For tied file handle calls, use PUSH* when we know that the stack has space.
[p5sagit/p5-mst-13.2.git] / regexec.c
index e2fc13e..50807e4 100644 (file)
--- a/regexec.c
+++ b/regexec.c
@@ -2,7 +2,11 @@
  */
 
 /*
- * "One Ring to rule them all, One Ring to find them..."
+ *     One Ring to rule them all, One Ring to find them
+ &
+ *     [p.v of _The Lord of the Rings_, opening poem]
+ *     [p.50 of _The Lord of the Rings_, I/iii: "The Shadow of the Past"]
+ *     [p.254 of _The Lord of the Rings_, II/ii: "The Council of Elrond"]
  */
 
 /* This file contains functions for executing a regular expression.  See
@@ -13,7 +17,6 @@
  * it's built with -DPERL_EXT_RE_BUILD -DPERL_EXT_RE_DEBUG -DPERL_EXT.
  * This causes the main functions to be compiled under new names and with
  * debugging support added, which makes "use re 'debug'" work.
  */
 
 /* NOTE: this is derived from Henry Spencer's regexp code, and should not
@@ -57,7 +60,8 @@
  ****    Alterations to Henry's code are...
  ****
  ****    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- ****    2000, 2001, 2002, 2003, 2004, 2005, 2006, by Larry Wall and others
+ ****    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ ****    by Larry Wall and others
  ****
  ****    You may distribute under the terms of either the GNU General Public
  ****    License or the Artistic License, as specified in the README file.
 
 #define RF_tainted     1               /* tainted information used? */
 #define RF_warned      2               /* warned about big count? */
-#define RF_evaled      4               /* Did an EVAL with setting? */
-#define RF_utf8                8               /* String contains multibyte chars? */
 
-#define UTF ((PL_reg_flags & RF_utf8) != 0)
+#define RF_utf8                8               /* Pattern contains multibyte chars? */
+
+#define UTF_PATTERN ((PL_reg_flags & RF_utf8) != 0)
 
 #define RS_init                1               /* eval environment created */
 #define RS_set         2               /* replsv value is set */
  * Forwards.
  */
 
-#define CHR_SVLEN(sv) (do_utf8 ? sv_len_utf8(sv) : SvCUR(sv))
+#define CHR_SVLEN(sv) (utf8_target ? sv_len_utf8(sv) : SvCUR(sv))
 #define CHR_DIST(a,b) (PL_reg_match_utf8 ? utf8_distance(a,b) : a - b)
 
-#define HOPc(pos,off) ((char *)(PL_reg_match_utf8 \
+#define HOPc(pos,off) \
+       (char *)(PL_reg_match_utf8 \
            ? reghop3((U8*)pos, off, (U8*)(off >= 0 ? PL_regeol : PL_bostr)) \
-           : (U8*)(pos + off)))
-#define HOPBACKc(pos, off) ((char*)    \
-    ((PL_reg_match_utf8)               \
-       ? reghopmaybe3((U8*)pos, -off, ((U8*)(off < 0 ? PL_regeol : PL_bostr))) \
-    : (pos - off >= PL_bostr)          \
-       ? (U8*)(pos - off)              \
-    : (U8*)NULL)                       \
-)
-
-#define reghopmaybe3_c(pos,off,lim) ((char*)reghopmaybe3((U8*)pos, off, (U8*)lim))
-#define HOP3(pos,off,lim) (PL_reg_match_utf8 ? reghop3((U8*)pos, off, (U8*)lim) : (U8*)(pos + off))
+           : (U8*)(pos + off))
+#define HOPBACKc(pos, off) \
+       (char*)(PL_reg_match_utf8\
+           ? reghopmaybe3((U8*)pos, -off, (U8*)PL_bostr) \
+           : (pos - off >= PL_bostr)           \
+               ? (U8*)pos - off                \
+               : NULL)
+
+#define HOP3(pos,off,lim) (PL_reg_match_utf8 ? reghop3((U8*)(pos), off, (U8*)(lim)) : (U8*)(pos + off))
 #define HOP3c(pos,off,lim) ((char*)HOP3(pos,off,lim))
 
+/* these are unrolled below in the CCC_TRY_XXX defined */
 #define LOAD_UTF8_CHARCLASS(class,str) STMT_START { \
     if (!CAT2(PL_utf8_,class)) { bool ok; ENTER; save_re_context(); ok=CAT2(is_utf8_,class)((const U8*)str); assert(ok); LEAVE; } } STMT_END
+
+/* Doesn't do an assert to verify that is correct */
+#define LOAD_UTF8_CHARCLASS_NO_CHECK(class) STMT_START { \
+    if (!CAT2(PL_utf8_,class)) { bool ok; ENTER; save_re_context(); ok=CAT2(is_utf8_,class)((const U8*)" "); LEAVE; } } STMT_END
+
 #define LOAD_UTF8_CHARCLASS_ALNUM() LOAD_UTF8_CHARCLASS(alnum,"a")
 #define LOAD_UTF8_CHARCLASS_DIGIT() LOAD_UTF8_CHARCLASS(digit,"0")
 #define LOAD_UTF8_CHARCLASS_SPACE() LOAD_UTF8_CHARCLASS(space," ")
-#define LOAD_UTF8_CHARCLASS_MARK()  LOAD_UTF8_CHARCLASS(mark, "\xcd\x86")
+
+#define LOAD_UTF8_CHARCLASS_GCB()  /* Grapheme cluster boundaries */        \
+       LOAD_UTF8_CHARCLASS(X_begin, " ");                                  \
+       LOAD_UTF8_CHARCLASS(X_non_hangul, "A");                             \
+       /* These are utf8 constants, and not utf-ebcdic constants, so the   \
+           * assert should likely and hopefully fail on an EBCDIC machine */ \
+       LOAD_UTF8_CHARCLASS(X_extend, "\xcc\x80"); /* U+0300 */             \
+                                                                           \
+       /* No asserts are done for these, in case called on an early        \
+           * Unicode version in which they map to nothing */               \
+       LOAD_UTF8_CHARCLASS_NO_CHECK(X_prepend);/* U+0E40 "\xe0\xb9\x80" */ \
+       LOAD_UTF8_CHARCLASS_NO_CHECK(X_L);          /* U+1100 "\xe1\x84\x80" */ \
+       LOAD_UTF8_CHARCLASS_NO_CHECK(X_LV);     /* U+AC00 "\xea\xb0\x80" */ \
+       LOAD_UTF8_CHARCLASS_NO_CHECK(X_LVT);    /* U+AC01 "\xea\xb0\x81" */ \
+       LOAD_UTF8_CHARCLASS_NO_CHECK(X_LV_LVT_V);/* U+AC01 "\xea\xb0\x81" */\
+       LOAD_UTF8_CHARCLASS_NO_CHECK(X_T);      /* U+11A8 "\xe1\x86\xa8" */ \
+       LOAD_UTF8_CHARCLASS_NO_CHECK(X_V)       /* U+1160 "\xe1\x85\xa0" */  
+
+/* 
+   We dont use PERL_LEGACY_UNICODE_CHARCLASS_MAPPINGS as the direct test
+   so that it is possible to override the option here without having to 
+   rebuild the entire core. as we are required to do if we change regcomp.h
+   which is where PERL_LEGACY_UNICODE_CHARCLASS_MAPPINGS is defined.
+*/
+#if PERL_LEGACY_UNICODE_CHARCLASS_MAPPINGS
+#define BROKEN_UNICODE_CHARCLASS_MAPPINGS
+#endif
+
+#ifdef BROKEN_UNICODE_CHARCLASS_MAPPINGS
+#define LOAD_UTF8_CHARCLASS_PERL_WORD()   LOAD_UTF8_CHARCLASS_ALNUM()
+#define LOAD_UTF8_CHARCLASS_PERL_SPACE()  LOAD_UTF8_CHARCLASS_SPACE()
+#define LOAD_UTF8_CHARCLASS_POSIX_DIGIT() LOAD_UTF8_CHARCLASS_DIGIT()
+#define RE_utf8_perl_word   PL_utf8_alnum
+#define RE_utf8_perl_space  PL_utf8_space
+#define RE_utf8_posix_digit PL_utf8_digit
+#define perl_word  alnum
+#define perl_space space
+#define posix_digit digit
+#else
+#define LOAD_UTF8_CHARCLASS_PERL_WORD()   LOAD_UTF8_CHARCLASS(perl_word,"a")
+#define LOAD_UTF8_CHARCLASS_PERL_SPACE()  LOAD_UTF8_CHARCLASS(perl_space," ")
+#define LOAD_UTF8_CHARCLASS_POSIX_DIGIT() LOAD_UTF8_CHARCLASS(posix_digit,"0")
+#define RE_utf8_perl_word   PL_utf8_perl_word
+#define RE_utf8_perl_space  PL_utf8_perl_space
+#define RE_utf8_posix_digit PL_utf8_posix_digit
+#endif
+
+
+#define CCC_TRY_AFF(NAME,NAMEL,CLASS,STR,LCFUNC_utf8,FUNC,LCFUNC)                          \
+        case NAMEL:                                                              \
+            PL_reg_flags |= RF_tainted;                                                 \
+            /* FALL THROUGH */                                                          \
+        case NAME:                                                                     \
+            if (!nextchr)                                                               \
+                sayNO;                                                                  \
+            if (utf8_target && UTF8_IS_CONTINUED(nextchr)) {                                \
+                if (!CAT2(PL_utf8_,CLASS)) {                                            \
+                    bool ok;                                                            \
+                    ENTER;                                                              \
+                    save_re_context();                                                  \
+                    ok=CAT2(is_utf8_,CLASS)((const U8*)STR);                            \
+                    assert(ok);                                                         \
+                    LEAVE;                                                              \
+                }                                                                       \
+                if (!(OP(scan) == NAME                                                  \
+                    ? cBOOL(swash_fetch(CAT2(PL_utf8_,CLASS), (U8*)locinput, utf8_target))  \
+                    : LCFUNC_utf8((U8*)locinput)))                                      \
+                {                                                                       \
+                    sayNO;                                                              \
+                }                                                                       \
+                locinput += PL_utf8skip[nextchr];                                       \
+                nextchr = UCHARAT(locinput);                                            \
+                break;                                                                  \
+            }                                                                           \
+            if (!(OP(scan) == NAME ? FUNC(nextchr) : LCFUNC(nextchr)))                  \
+                sayNO;                                                                  \
+            nextchr = UCHARAT(++locinput);                                              \
+            break
+
+#define CCC_TRY_NEG(NAME,NAMEL,CLASS,STR,LCFUNC_utf8,FUNC,LCFUNC)                        \
+        case NAMEL:                                                              \
+            PL_reg_flags |= RF_tainted;                                                 \
+            /* FALL THROUGH */                                                          \
+        case NAME :                                                                     \
+            if (!nextchr && locinput >= PL_regeol)                                      \
+                sayNO;                                                                  \
+            if (utf8_target && UTF8_IS_CONTINUED(nextchr)) {                                \
+                if (!CAT2(PL_utf8_,CLASS)) {                                            \
+                    bool ok;                                                            \
+                    ENTER;                                                              \
+                    save_re_context();                                                  \
+                    ok=CAT2(is_utf8_,CLASS)((const U8*)STR);                            \
+                    assert(ok);                                                         \
+                    LEAVE;                                                              \
+                }                                                                       \
+                if ((OP(scan) == NAME                                                  \
+                    ? cBOOL(swash_fetch(CAT2(PL_utf8_,CLASS), (U8*)locinput, utf8_target))  \
+                    : LCFUNC_utf8((U8*)locinput)))                                      \
+                {                                                                       \
+                    sayNO;                                                              \
+                }                                                                       \
+                locinput += PL_utf8skip[nextchr];                                       \
+                nextchr = UCHARAT(locinput);                                            \
+                break;                                                                  \
+            }                                                                           \
+            if ((OP(scan) == NAME ? FUNC(nextchr) : LCFUNC(nextchr)))                   \
+                sayNO;                                                                  \
+            nextchr = UCHARAT(++locinput);                                              \
+            break
+
+
+
+
+
+/* TODO: Combine JUMPABLE and HAS_TEXT to cache OP(rn) */
 
 /* for use after a quantifier and before an EXACT-like node -- japhy */
-#define JUMPABLE(rn) ( \
-    OP(rn) == OPEN || OP(rn) == CLOSE || OP(rn) == EVAL || \
+/* it would be nice to rework regcomp.sym to generate this stuff. sigh */
+#define JUMPABLE(rn) (      \
+    OP(rn) == OPEN ||       \
+    (OP(rn) == CLOSE && (!cur_eval || cur_eval->u.eval.close_paren != ARG(rn))) || \
+    OP(rn) == EVAL ||   \
     OP(rn) == SUSPEND || OP(rn) == IFMATCH || \
     OP(rn) == PLUS || OP(rn) == MINMOD || \
-    (PL_regkind[(U8)OP(rn)] == CURLY && ARG1(rn) > 0) \
+    OP(rn) == KEEPS || (PL_regkind[OP(rn)] == VERB) || \
+    (PL_regkind[OP(rn)] == CURLY && ARG1(rn) > 0) \
 )
+#define IS_EXACT(rn) (PL_regkind[OP(rn)] == EXACT)
 
-#define HAS_TEXT(rn) ( \
-    PL_regkind[(U8)OP(rn)] == EXACT || PL_regkind[(U8)OP(rn)] == REF \
-)
+#define HAS_TEXT(rn) ( IS_EXACT(rn) || PL_regkind[OP(rn)] == REF )
+
+#if 0 
+/* Currently these are only used when PL_regkind[OP(rn)] == EXACT so
+   we don't need this definition. */
+#define IS_TEXT(rn)   ( OP(rn)==EXACT   || OP(rn)==REF   || OP(rn)==NREF   )
+#define IS_TEXTF(rn)  ( OP(rn)==EXACTF  || OP(rn)==REFF  || OP(rn)==NREFF  )
+#define IS_TEXTFL(rn) ( OP(rn)==EXACTFL || OP(rn)==REFFL || OP(rn)==NREFFL )
+
+#else
+/* ... so we use this as its faster. */
+#define IS_TEXT(rn)   ( OP(rn)==EXACT   )
+#define IS_TEXTF(rn)  ( OP(rn)==EXACTF  )
+#define IS_TEXTFL(rn) ( OP(rn)==EXACTFL )
+
+#endif
 
 /*
   Search for mandatory following text node; for lookahead, the text must
   follow but for lookbehind (rn->flags != 0) we skip to the next step.
 */
 #define FIND_NEXT_IMPT(rn) STMT_START { \
-    while (JUMPABLE(rn)) \
-       if (OP(rn) == SUSPEND || PL_regkind[(U8)OP(rn)] == CURLY) \
+    while (JUMPABLE(rn)) { \
+       const OPCODE type = OP(rn); \
+       if (type == SUSPEND || PL_regkind[type] == CURLY) \
            rn = NEXTOPER(NEXTOPER(rn)); \
-       else if (OP(rn) == PLUS) \
+       else if (type == PLUS) \
            rn = NEXTOPER(rn); \
-       else if (OP(rn) == IFMATCH) \
+       else if (type == IFMATCH) \
            rn = (rn->flags == 0) ? NEXTOPER(NEXTOPER(rn)) : rn + ARG(rn); \
        else rn += NEXT_OFF(rn); \
+    } \
 } STMT_END 
 
+
 static void restore_pos(pTHX_ void *arg);
 
+#define REGCP_PAREN_ELEMS 4
+#define REGCP_OTHER_ELEMS 5
+#define REGCP_FRAME_ELEMS 1
+/* REGCP_FRAME_ELEMS are not part of the REGCP_OTHER_ELEMS and
+ * are needed for the regexp context stack bookkeeping. */
+
 STATIC CHECKPOINT
 S_regcppush(pTHX_ I32 parenfloor)
 {
     dVAR;
     const int retval = PL_savestack_ix;
-#define REGCP_PAREN_ELEMS 4
     const int paren_elems_to_push = (PL_regsize - parenfloor) * REGCP_PAREN_ELEMS;
+    const UV total_elems = paren_elems_to_push + REGCP_OTHER_ELEMS;
+    const UV elems_shifted = total_elems << SAVE_TIGHT_SHIFT;
     int p;
+    GET_RE_DEBUG_FLAGS_DECL;
 
     if (paren_elems_to_push < 0)
        Perl_croak(aTHX_ "panic: paren_elems_to_push < 0");
 
-#define REGCP_OTHER_ELEMS 6
-    SSGROW(paren_elems_to_push + REGCP_OTHER_ELEMS);
+    if ((elems_shifted >> SAVE_TIGHT_SHIFT) != total_elems)
+       Perl_croak(aTHX_ "panic: paren_elems_to_push offset %"UVuf
+                  " out of range (%lu-%ld)",
+                  total_elems, (unsigned long)PL_regsize, (long)parenfloor);
+
+    SSGROW(total_elems + REGCP_FRAME_ELEMS);
+    
     for (p = PL_regsize; p > parenfloor; p--) {
 /* REGCP_PARENS_ELEMS are pushed per pairs of parentheses. */
-       SSPUSHINT(PL_regendp[p]);
-       SSPUSHINT(PL_regstartp[p]);
+       SSPUSHINT(PL_regoffs[p].end);
+       SSPUSHINT(PL_regoffs[p].start);
        SSPUSHPTR(PL_reg_start_tmp[p]);
        SSPUSHINT(p);
+       DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
+         "     saving \\%"UVuf" %"IVdf"(%"IVdf")..%"IVdf"\n",
+                     (UV)p, (IV)PL_regoffs[p].start,
+                     (IV)(PL_reg_start_tmp[p] - PL_bostr),
+                     (IV)PL_regoffs[p].end
+       ));
     }
 /* REGCP_OTHER_ELEMS are pushed in any case, parentheses or no. */
+    SSPUSHPTR(PL_regoffs);
     SSPUSHINT(PL_regsize);
     SSPUSHINT(*PL_reglastparen);
     SSPUSHINT(*PL_reglastcloseparen);
     SSPUSHPTR(PL_reginput);
-#define REGCP_FRAME_ELEMS 2
-/* REGCP_FRAME_ELEMS are part of the REGCP_OTHER_ELEMS and
- * are needed for the regexp context stack bookkeeping. */
-    SSPUSHINT(paren_elems_to_push + REGCP_OTHER_ELEMS - REGCP_FRAME_ELEMS);
-    SSPUSHINT(SAVEt_REGCONTEXT); /* Magic cookie. */
+    SSPUSHUV(SAVEt_REGCONTEXT | elems_shifted); /* Magic cookie. */
 
     return retval;
 }
 
 /* These are needed since we do not localize EVAL nodes: */
-#  define REGCP_SET(cp)  DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,         \
-                            "  Setting an EVAL scope, savestack=%"IVdf"\n",    \
-                            (IV)PL_savestack_ix)); cp = PL_savestack_ix
-
-#  define REGCP_UNWIND(cp)  DEBUG_EXECUTE_r(cp != PL_savestack_ix ?            \
-                               PerlIO_printf(Perl_debug_log,           \
-                               "  Clearing an EVAL scope, savestack=%"IVdf"..%"IVdf"\n", \
-                               (IV)(cp), (IV)PL_savestack_ix) : 0); regcpblow(cp)
+#define REGCP_SET(cp)                                           \
+    DEBUG_STATE_r(                                              \
+            PerlIO_printf(Perl_debug_log,                      \
+               "  Setting an EVAL scope, savestack=%"IVdf"\n", \
+               (IV)PL_savestack_ix));                          \
+    cp = PL_savestack_ix
+
+#define REGCP_UNWIND(cp)                                        \
+    DEBUG_STATE_r(                                              \
+        if (cp != PL_savestack_ix)                             \
+           PerlIO_printf(Perl_debug_log,                       \
+               "  Clearing an EVAL scope, savestack=%"IVdf"..%"IVdf"\n", \
+               (IV)(cp), (IV)PL_savestack_ix));                \
+    regcpblow(cp)
 
 STATIC char *
 S_regcppop(pTHX_ const regexp *rex)
 {
     dVAR;
-    I32 i;
+    UV i;
     char *input;
-
     GET_RE_DEBUG_FLAGS_DECL;
 
+    PERL_ARGS_ASSERT_REGCPPOP;
+
     /* Pop REGCP_OTHER_ELEMS before the parentheses loop starts. */
-    i = SSPOPINT;
-    assert(i == SAVEt_REGCONTEXT); /* Check that the magic cookie is there. */
-    i = SSPOPINT; /* Parentheses elements to pop. */
+    i = SSPOPUV;
+    assert((i & SAVE_MASK) == SAVEt_REGCONTEXT); /* Check that the magic cookie is there. */
+    i >>= SAVE_TIGHT_SHIFT; /* Parentheses elements to pop. */
     input = (char *) SSPOPPTR;
     *PL_reglastcloseparen = SSPOPINT;
     *PL_reglastparen = SSPOPINT;
     PL_regsize = SSPOPINT;
+    PL_regoffs=(regexp_paren_pair *) SSPOPPTR;
 
+    i -= REGCP_OTHER_ELEMS;
     /* Now restore the parentheses context. */
-    for (i -= (REGCP_OTHER_ELEMS - REGCP_FRAME_ELEMS);
-        i > 0; i -= REGCP_PAREN_ELEMS) {
+    for ( ; i > 0; i -= REGCP_PAREN_ELEMS) {
        I32 tmps;
        U32 paren = (U32)SSPOPINT;
        PL_reg_start_tmp[paren] = (char *) SSPOPPTR;
-       PL_regstartp[paren] = SSPOPINT;
+       PL_regoffs[paren].start = SSPOPINT;
        tmps = SSPOPINT;
        if (paren <= *PL_reglastparen)
-           PL_regendp[paren] = tmps;
-       DEBUG_EXECUTE_r(
+           PL_regoffs[paren].end = tmps;
+       DEBUG_BUFFERS_r(
            PerlIO_printf(Perl_debug_log,
                          "     restoring \\%"UVuf" to %"IVdf"(%"IVdf")..%"IVdf"%s\n",
-                         (UV)paren, (IV)PL_regstartp[paren],
+                         (UV)paren, (IV)PL_regoffs[paren].start,
                          (IV)(PL_reg_start_tmp[paren] - PL_bostr),
-                         (IV)PL_regendp[paren],
+                         (IV)PL_regoffs[paren].end,
                          (paren > *PL_reglastparen ? "(no)" : ""));
        );
     }
-    DEBUG_EXECUTE_r(
-       if ((I32)(*PL_reglastparen + 1) <= rex->nparens) {
+    DEBUG_BUFFERS_r(
+       if (*PL_reglastparen + 1 <= rex->nparens) {
            PerlIO_printf(Perl_debug_log,
                          "     restoring \\%"IVdf"..\\%"IVdf" to undef\n",
                          (IV)(*PL_reglastparen + 1), (IV)rex->nparens);
@@ -247,13 +415,12 @@ S_regcppop(pTHX_ const regexp *rex)
      * requiring null fields (pat.t#187 and split.t#{13,14}
      * (as of patchlevel 7877)  will fail.  Then again,
      * this code seems to be necessary or otherwise
-     * building DynaLoader will fail:
-     * "Error: '*' not in typemap in DynaLoader.xs, line 164"
-     * --jhi */
+     * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
+     * --jhi updated by dapm */
     for (i = *PL_reglastparen + 1; i <= rex->nparens; i++) {
        if (i > PL_regsize)
-           PL_regstartp[i] = -1;
-       PL_regendp[i] = -1;
+           PL_regoffs[i].start = -1;
+       PL_regoffs[i].end = -1;
     }
 #endif
     return input;
@@ -261,23 +428,6 @@ S_regcppop(pTHX_ const regexp *rex)
 
 #define regcpblow(cp) LEAVE_SCOPE(cp)  /* Ignores regcppush()ed data. */
 
-#define TRYPAREN(paren, n, input, where) {                     \
-    if (paren) {                                               \
-       if (n) {                                                \
-           PL_regstartp[paren] = HOPc(input, -1) - PL_bostr;   \
-           PL_regendp[paren] = input - PL_bostr;               \
-       }                                                       \
-       else                                                    \
-           PL_regendp[paren] = -1;                             \
-    }                                                          \
-    REGMATCH(next, where);                                     \
-    if (result)                                                        \
-       sayYES;                                                 \
-    if (paren && n)                                            \
-       PL_regendp[paren] = -1;                                 \
-}
-
-
 /*
  * pregexec and friends
  */
@@ -287,13 +437,15 @@ S_regcppop(pTHX_ const regexp *rex)
  - pregexec - match a regexp against a string
  */
 I32
-Perl_pregexec(pTHX_ register regexp *prog, char *stringarg, register char *strend,
+Perl_pregexec(pTHX_ REGEXP * const prog, char* stringarg, register char *strend,
         char *strbeg, I32 minend, SV *screamer, U32 nosave)
 /* strend: pointer to null at end of string */
 /* strbeg: real beginning of string */
 /* minend: end of match must be >=minend after stringarg. */
 /* nosave: For optimizations. */
 {
+    PERL_ARGS_ASSERT_PREGEXEC;
+
     return
        regexec_flags(prog, stringarg, strend, strbeg, minend, screamer, NULL,
                      nosave ? 0 : REXEC_COPY_STR);
@@ -326,7 +478,11 @@ Perl_pregexec(pTHX_ register regexp *prog, char *stringarg, register char *stren
        RExen without fixed substrings.  Similarly, it is assumed that
        lengths of all the strings are no more than minlen, thus they
        cannot come from lookahead.
-       (Or minlen should take into account lookahead.) */
+       (Or minlen should take into account lookahead.) 
+  NOTE: Some of this comment is not correct. minlen does now take account
+  of lookahead/behind. Further research is required. -- demerphq
+
+*/
 
 /* A failure to find a constant substring means that there is no need to make
    an expensive call to REx engine, thus we celebrate a failure.  Similarly,
@@ -347,10 +503,11 @@ Perl_pregexec(pTHX_ register regexp *prog, char *stringarg, register char *stren
    deleted from the finite automaton. */
 
 char *
-Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
-                    char *strend, U32 flags, re_scream_pos_data *data)
+Perl_re_intuit_start(pTHX_ REGEXP * const rx, SV *sv, char *strpos,
+                    char *strend, const U32 flags, re_scream_pos_data *data)
 {
     dVAR;
+    struct regexp *const prog = (struct regexp *)SvANY(rx);
     register I32 start_shift = 0;
     /* Should be nonnegative! */
     register I32 end_shift   = 0;
@@ -358,49 +515,29 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     register SV *check;
     char *strbeg;
     char *t;
-    const int do_utf8 = sv ? SvUTF8(sv) : 0;   /* if no sv we have to assume bytes */
+    const bool utf8_target = (sv && SvUTF8(sv)) ? 1 : 0; /* if no sv we have to assume bytes */
     I32 ml_anch;
     register char *other_last = NULL;  /* other substr checked before this */
     char *check_at = NULL;             /* check substr found at this pos */
-    const I32 multiline = prog->reganch & PMf_MULTILINE;
+    const I32 multiline = prog->extflags & RXf_PMf_MULTILINE;
+    RXi_GET_DECL(prog,progi);
 #ifdef DEBUGGING
     const char * const i_strpos = strpos;
-    SV * const dsv = PERL_DEBUG_PAD_ZERO(0);
 #endif
-
     GET_RE_DEBUG_FLAGS_DECL;
 
-    RX_MATCH_UTF8_set(prog,do_utf8);
+    PERL_ARGS_ASSERT_RE_INTUIT_START;
 
-    if (prog->reganch & ROPT_UTF8) {
-       DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
-                             "UTF-8 regex...\n"));
+    RX_MATCH_UTF8_set(rx,utf8_target);
+
+    if (RX_UTF8(rx)) {
        PL_reg_flags |= RF_utf8;
     }
-
-    DEBUG_EXECUTE_r({
-        const char *s   = PL_reg_match_utf8 ?
-                        sv_uni_display(dsv, sv, 60, UNI_DISPLAY_REGEX) :
-                        strpos;
-        const int   len = PL_reg_match_utf8 ?
-                        strlen(s) : strend - strpos;
-        if (!PL_colorset)
-             reginitcolors();
-        if (PL_reg_match_utf8)
-            DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
-                                  "UTF-8 target...\n"));
-        PerlIO_printf(Perl_debug_log,
-                      "%sGuessing start of match, REx%s \"%s%.60s%s%s\" against \"%s%.*s%s%s\"...\n",
-                      PL_colors[4], PL_colors[5], PL_colors[0],
-                      prog->precomp,
-                      PL_colors[1],
-                      (strlen(prog->precomp) > 60 ? "..." : ""),
-                      PL_colors[0],
-                      (int)(len > 60 ? 60 : len),
-                      s, PL_colors[1],
-                      (len > 60 ? "..." : "")
+    DEBUG_EXECUTE_r( 
+        debug_start_match(rx, utf8_target, strpos, strend,
+            sv ? "Guessing start of match in sv for"
+               : "Guessing start of match in string for");
              );
-    });
 
     /* CHR_DIST() would be more correct here but it makes things slow. */
     if (prog->minlen > strend - strpos) {
@@ -408,9 +545,10 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                              "String too short... [re_intuit_start]\n"));
        goto fail;
     }
+                
     strbeg = (sv && SvPOK(sv)) ? strend - SvCUR(sv) : strpos;
     PL_regeol = strend;
-    if (do_utf8) {
+    if (utf8_target) {
        if (!prog->check_utf8 && prog->check_substr)
            to_utf8_substr(prog);
        check = prog->check_utf8;
@@ -419,19 +557,19 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
            to_byte_substr(prog);
        check = prog->check_substr;
     }
-   if (check == &PL_sv_undef) {
+    if (check == &PL_sv_undef) {
        DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
-               "Non-utf string cannot match utf check string\n"));
+               "Non-utf8 string cannot match utf8 check string\n"));
        goto fail;
     }
-    if (prog->reganch & ROPT_ANCH) {   /* Match at beg-of-str or after \n */
-       ml_anch = !( (prog->reganch & ROPT_ANCH_SINGLE)
-                    || ( (prog->reganch & ROPT_ANCH_BOL)
+    if (prog->extflags & RXf_ANCH) {   /* Match at beg-of-str or after \n */
+       ml_anch = !( (prog->extflags & RXf_ANCH_SINGLE)
+                    || ( (prog->extflags & RXf_ANCH_BOL)
                          && !multiline ) );    /* Check after \n? */
 
        if (!ml_anch) {
-         if ( !(prog->reganch & (ROPT_ANCH_GPOS /* Checked by the caller */
-                                 | ROPT_IMPLICIT)) /* not a real BOL */
+         if ( !(prog->extflags & RXf_ANCH_GPOS) /* Checked by the caller */
+               && !(prog->intflags & PREGf_IMPLICIT) /* not a real BOL */
               /* SvCUR is not set on references: SvRV and SvPVX_const overlap */
               && sv && !SvROK(sv)
               && (strpos != strbeg)) {
@@ -439,11 +577,12 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
              goto fail;
          }
          if (prog->check_offset_min == prog->check_offset_max &&
-             !(prog->reganch & ROPT_CANY_SEEN)) {
+             !(prog->extflags & RXf_CANY_SEEN)) {
            /* Substring at constant offset from beg-of-str... */
            I32 slen;
 
            s = HOP3c(strpos, prog->check_offset_min, strend);
+           
            if (SvTAIL(check)) {
                slen = SvCUR(check);    /* >= 1 */
 
@@ -473,8 +612,8 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        /* Match is anchored, but substr is not anchored wrt beg-of-str. */
        s = strpos;
        start_shift = prog->check_offset_min; /* okay to underestimate on CC */
-       end_shift = prog->minlen - start_shift -
-           CHR_SVLEN(check) + (SvTAIL(check) != 0);
+       end_shift = prog->check_end_shift;
+       
        if (!ml_anch) {
            const I32 end = prog->check_offset_max + CHR_SVLEN(check)
                                         - (SvTAIL(check) != 0);
@@ -487,20 +626,37 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     else {                             /* Can match at random position */
        ml_anch = 0;
        s = strpos;
-       start_shift = prog->check_offset_min; /* okay to underestimate on CC */
-       /* Should be nonnegative! */
-       end_shift = prog->minlen - start_shift -
-           CHR_SVLEN(check) + (SvTAIL(check) != 0);
+       start_shift = prog->check_offset_min;  /* okay to underestimate on CC */
+       end_shift = prog->check_end_shift;
+       
+       /* end shift should be non negative here */
     }
 
-#ifdef DEBUGGING       /* 7/99: reports of failure (with the older version) */
+#ifdef QDEBUGGING      /* 7/99: reports of failure (with the older version) */
     if (end_shift < 0)
-       Perl_croak(aTHX_ "panic: end_shift");
+       Perl_croak(aTHX_ "panic: end_shift: %"IVdf" pattern:\n%s\n ",
+                  (IV)end_shift, RX_PRECOMP(prog));
 #endif
 
   restart:
     /* Find a possible match in the region s..strend by looking for
        the "check" substring in the region corrected by start/end_shift. */
+    
+    {
+        I32 srch_start_shift = start_shift;
+        I32 srch_end_shift = end_shift;
+        if (srch_start_shift < 0 && strbeg - s > srch_start_shift) {
+           srch_end_shift -= ((strbeg - s) - srch_start_shift); 
+           srch_start_shift = strbeg - s;
+       }
+    DEBUG_OPTIMISE_MORE_r({
+        PerlIO_printf(Perl_debug_log, "Check offset min: %"IVdf" Start shift: %"IVdf" End shift %"IVdf" Real End Shift: %"IVdf"\n",
+            (IV)prog->check_offset_min,
+            (IV)srch_start_shift,
+            (IV)srch_end_shift, 
+            (IV)prog->check_end_shift);
+    });       
+        
     if (flags & REXEC_SCREAM) {
        I32 p = -1;                     /* Internal iterator of scream. */
        I32 * const pp = data ? data->scream_pos : &p;
@@ -510,44 +666,67 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                 && (BmPREVIOUS(check) == SvCUR(check) - 1)
                 && SvTAIL(check) ))
            s = screaminstr(sv, check,
-                           start_shift + (s - strbeg), end_shift, pp, 0);
+                           srch_start_shift + (s - strbeg), srch_end_shift, pp, 0);
        else
            goto fail_finish;
        /* we may be pointing at the wrong string */
-       if (s && RX_MATCH_COPIED(prog))
+       if (s && RXp_MATCH_COPIED(prog))
            s = strbeg + (s - SvPVX_const(sv));
        if (data)
            *data->scream_olds = s;
     }
-    else if (prog->reganch & ROPT_CANY_SEEN)
-       s = fbm_instr((U8*)(s + start_shift),
-                     (U8*)(strend - end_shift),
-                     check, multiline ? FBMrf_MULTILINE : 0);
-    else
-       s = fbm_instr(HOP3(s, start_shift, strend),
-                     HOP3(strend, -end_shift, strbeg),
+    else {
+        U8* start_point;
+        U8* end_point;
+        if (prog->extflags & RXf_CANY_SEEN) {
+            start_point= (U8*)(s + srch_start_shift);
+            end_point= (U8*)(strend - srch_end_shift);
+        } else {
+           start_point= HOP3(s, srch_start_shift, srch_start_shift < 0 ? strbeg : strend);
+            end_point= HOP3(strend, -srch_end_shift, strbeg);
+       }
+       DEBUG_OPTIMISE_MORE_r({
+            PerlIO_printf(Perl_debug_log, "fbm_instr len=%d str=<%.*s>\n", 
+                (int)(end_point - start_point),
+                (int)(end_point - start_point) > 20 ? 20 : (int)(end_point - start_point), 
+                start_point);
+        });
+
+       s = fbm_instr( start_point, end_point,
                      check, multiline ? FBMrf_MULTILINE : 0);
-
+    }
+    }
     /* Update the count-of-usability, remove useless subpatterns,
        unshift s.  */
 
-    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s %s substr \"%s%.*s%s\"%s%s",
+    DEBUG_EXECUTE_r({
+        RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
+            SvPVX_const(check), RE_SV_DUMPLEN(check), 30);
+        PerlIO_printf(Perl_debug_log, "%s %s substr %s%s%s",
                          (s ? "Found" : "Did not find"),
-                         (check == (do_utf8 ? prog->anchored_utf8 : prog->anchored_substr) ? "anchored" : "floating"),
-                         PL_colors[0],
-                         (int)(SvCUR(check) - (SvTAIL(check)!=0)),
-                         SvPVX_const(check),
-                         PL_colors[1], (SvTAIL(check) ? "$" : ""),
-                         (s ? " at offset " : "...\n") ) );
+           (check == (utf8_target ? prog->anchored_utf8 : prog->anchored_substr)
+               ? "anchored" : "floating"),
+           quoted,
+           RE_SV_TAIL(check),
+           (s ? " at offset " : "...\n") ); 
+    });
 
     if (!s)
        goto fail_finish;
-
-    check_at = s;
-
     /* Finish the diagnostic message */
     DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%ld...\n", (long)(s - i_strpos)) );
 
+    /* XXX dmq: first branch is for positive lookbehind...
+       Our check string is offset from the beginning of the pattern.
+       So we need to do any stclass tests offset forward from that 
+       point. I think. :-(
+     */
+    
+        
+    
+    check_at=s;
+     
+
     /* Got a candidate.  Check MBOL anchoring, and the *other* substr.
        Start with the other substr.
        XXXX no SCREAM optimization yet - and a very coarse implementation
@@ -556,23 +735,25 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        Probably it is right to do no SCREAM here...
      */
 
-    if (do_utf8 ? (prog->float_utf8 && prog->anchored_utf8) : (prog->float_substr && prog->anchored_substr)) {
+    if (utf8_target ? (prog->float_utf8 && prog->anchored_utf8)
+                : (prog->float_substr && prog->anchored_substr)) 
+    {
        /* Take into account the "other" substring. */
        /* XXXX May be hopelessly wrong for UTF... */
        if (!other_last)
            other_last = strpos;
-       if (check == (do_utf8 ? prog->float_utf8 : prog->float_substr)) {
+       if (check == (utf8_target ? prog->float_utf8 : prog->float_substr)) {
          do_other_anchored:
            {
                char * const last = HOP3c(s, -start_shift, strbeg);
                char *last1, *last2;
-               char *s1 = s;
+               char * const saved_s = s;
                SV* must;
 
                t = s - prog->check_offset_max;
                if (s - strpos > prog->check_offset_max  /* signed-corrected t > strpos */
-                   && (!do_utf8
-                       || ((t = reghopmaybe3_c(s, -(prog->check_offset_max), strpos))
+                   && (!utf8_target
+                       || ((t = (char*)reghopmaybe3((U8*)s, -(prog->check_offset_max), (U8*)strpos))
                            && t > strpos)))
                    NOOP;
                else
@@ -583,12 +764,17 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                last2 = last1 = HOP3c(strend, -prog->minlen, strbeg);
                if (last < last1)
                    last1 = last;
- /* XXXX It is not documented what units *_offsets are in.  Assume bytes.  */
+                /* XXXX It is not documented what units *_offsets are in.  
+                   We assume bytes, but this is clearly wrong. 
+                   Meaning this code needs to be carefully reviewed for errors.
+                   dmq.
+                  */
                /* On end-of-str: see comment below. */
-               must = do_utf8 ? prog->anchored_utf8 : prog->anchored_substr;
+               must = utf8_target ? prog->anchored_utf8 : prog->anchored_substr;
                if (must == &PL_sv_undef) {
                    s = (char*)NULL;
-                   DEBUG_EXECUTE_r(must = prog->anchored_utf8);        /* for debug */
+                   DEBUG_r(must = prog->anchored_utf8);        /* for debug */
                }
                else
                    s = fbm_instr(
@@ -598,14 +784,15 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                        must,
                        multiline ? FBMrf_MULTILINE : 0
                    );
-               DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
-                       "%s anchored substr \"%s%.*s%s\"%s",
+                DEBUG_EXECUTE_r({
+                    RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
+                        SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
+                    PerlIO_printf(Perl_debug_log, "%s anchored substr %s%s",
                        (s ? "Found" : "Contradicts"),
-                       PL_colors[0],
-                         (int)(SvCUR(must)
-                         - (SvTAIL(must)!=0)),
-                         SvPVX_const(must),
-                         PL_colors[1], (SvTAIL(must) ? "$" : "")));
+                        quoted, RE_SV_TAIL(must));
+                });                
+               
+                           
                if (!s) {
                    if (last1 >= last2) {
                        DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
@@ -614,7 +801,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                    }
                    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
                        ", trying floating at offset %ld...\n",
-                       (long)(HOP3c(s1, 1, strend) - i_strpos)));
+                       (long)(HOP3c(saved_s, 1, strend) - i_strpos)));
                    other_last = HOP3c(last1, prog->anchored_offset+1, strend);
                    s = HOP3c(last, 1, strend);
                    goto restart;
@@ -624,7 +811,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                          (long)(s - i_strpos)));
                    t = HOP3c(s, -prog->anchored_offset, strbeg);
                    other_last = HOP3c(s, 1, strend);
-                   s = s1;
+                   s = saved_s;
                    if (t == strpos)
                        goto try_at_start;
                    goto try_at_offset;
@@ -633,7 +820,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        }
        else {          /* Take into account the floating substring. */
            char *last, *last1;
-           char *s1 = s;
+           char * const saved_s = s;
            SV* must;
 
            t = HOP3c(s, -start_shift, strbeg);
@@ -645,25 +832,26 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
            if (s < other_last)
                s = other_last;
  /* XXXX It is not documented what units *_offsets are in.  Assume bytes.  */
-           must = do_utf8 ? prog->float_utf8 : prog->float_substr;
+           must = utf8_target ? prog->float_utf8 : prog->float_substr;
            /* fbm_instr() takes into account exact value of end-of-str
               if the check is SvTAIL(ed).  Since false positives are OK,
               and end-of-str is not later than strend we are OK. */
            if (must == &PL_sv_undef) {
                s = (char*)NULL;
-               DEBUG_EXECUTE_r(must = prog->float_utf8);       /* for debug message */
+               DEBUG_r(must = prog->float_utf8);       /* for debug message */
            }
            else
                s = fbm_instr((unsigned char*)s,
                              (unsigned char*)last + SvCUR(must)
                                  - (SvTAIL(must)!=0),
                              must, multiline ? FBMrf_MULTILINE : 0);
-           DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s floating substr \"%s%.*s%s\"%s",
+           DEBUG_EXECUTE_r({
+               RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
+                   SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
+               PerlIO_printf(Perl_debug_log, "%s floating substr %s%s",
                    (s ? "Found" : "Contradicts"),
-                   PL_colors[0],
-                     (int)(SvCUR(must) - (SvTAIL(must)!=0)),
-                     SvPVX_const(must),
-                     PL_colors[1], (SvTAIL(must) ? "$" : "")));
+                   quoted, RE_SV_TAIL(must));
+            });
            if (!s) {
                if (last1 == last) {
                    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
@@ -672,7 +860,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                }
                DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
                    ", trying anchored starting at offset %ld...\n",
-                   (long)(s1 + 1 - i_strpos)));
+                   (long)(saved_s + 1 - i_strpos)));
                other_last = last;
                s = HOP3c(t, 1, strend);
                goto restart;
@@ -681,7 +869,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, " at offset %ld...\n",
                      (long)(s - i_strpos)));
                other_last = s; /* Fix this later. --Hugo */
-               s = s1;
+               s = saved_s;
                if (t == strpos)
                    goto try_at_start;
                goto try_at_offset;
@@ -689,11 +877,26 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        }
     }
 
-    t = s - prog->check_offset_max;
+    
+    t= (char*)HOP3( s, -prog->check_offset_max, (prog->check_offset_max<0) ? strend : strpos);
+        
+    DEBUG_OPTIMISE_MORE_r(
+        PerlIO_printf(Perl_debug_log, 
+            "Check offset min:%"IVdf" max:%"IVdf" S:%"IVdf" t:%"IVdf" D:%"IVdf" end:%"IVdf"\n",
+            (IV)prog->check_offset_min,
+            (IV)prog->check_offset_max,
+            (IV)(s-strpos),
+            (IV)(t-strpos),
+            (IV)(t-s),
+            (IV)(strend-strpos)
+        )
+    );
+
     if (s - strpos > prog->check_offset_max  /* signed-corrected t > strpos */
-        && (!do_utf8
-           || ((t = reghopmaybe3_c(s, -prog->check_offset_max, strpos))
-                && t > strpos))) {
+        && (!utf8_target
+           || ((t = (char*)reghopmaybe3((U8*)s, -prog->check_offset_max, (U8*) ((prog->check_offset_max<0) ? strend : strpos)))
+                && t > strpos))) 
+    {
        /* Fixed substring is found far enough so that the match
           cannot start at strpos. */
       try_at_offset:
@@ -708,7 +911,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
            while (t < strend - prog->minlen) {
                if (*t == '\n') {
                    if (t < check_at - prog->check_offset_min) {
-                       if (do_utf8 ? prog->anchored_utf8 : prog->anchored_substr) {
+                       if (utf8_target ? prog->anchored_utf8 : prog->anchored_substr) {
                            /* Since we moved from the found position,
                               we definitely contradict the found anchored
                               substr.  Due to the above check we do not
@@ -748,7 +951,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        }
        s = t;
       set_useful:
-       ++BmUSEFUL(do_utf8 ? prog->check_utf8 : prog->check_substr);    /* hooray/5 */
+       ++BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr);        /* hooray/5 */
     }
     else {
        /* The found string does not prohibit matching at strpos,
@@ -761,18 +964,18 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        if (ml_anch && sv && !SvROK(sv) /* See prev comment on SvROK */
            && (strpos != strbeg) && strpos[-1] != '\n'
            /* May be due to an implicit anchor of m{.*foo}  */
-           && !(prog->reganch & ROPT_IMPLICIT))
+           && !(prog->intflags & PREGf_IMPLICIT))
        {
            t = strpos;
            goto find_anchor;
        }
        DEBUG_EXECUTE_r( if (ml_anch)
            PerlIO_printf(Perl_debug_log, "Position at offset %ld does not contradict /%s^%s/m...\n",
-                       (long)(strpos - i_strpos), PL_colors[0], PL_colors[1]);
+                         (long)(strpos - i_strpos), PL_colors[0], PL_colors[1]);
        );
       success_at_start:
-       if (!(prog->reganch & ROPT_NAUGHTY)     /* XXXX If strpos moved? */
-           && (do_utf8 ? (
+       if (!(prog->intflags & PREGf_NAUGHTY)   /* XXXX If strpos moved? */
+           && (utf8_target ? (
                prog->check_utf8                /* Could be deleted already */
                && --BmUSEFUL(prog->check_utf8) < 0
                && (prog->check_utf8 == prog->float_utf8)
@@ -784,9 +987,9 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        {
            /* If flags & SOMETHING - do not do it many times on the same match */
            DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "... Disabling check substring...\n"));
-           SvREFCNT_dec(do_utf8 ? prog->check_utf8 : prog->check_substr);
-           if (do_utf8 ? prog->check_substr : prog->check_utf8)
-               SvREFCNT_dec(do_utf8 ? prog->check_substr : prog->check_utf8);
+           /* XXX Does the destruction order has to change with utf8_target? */
+           SvREFCNT_dec(utf8_target ? prog->check_utf8 : prog->check_substr);
+           SvREFCNT_dec(utf8_target ? prog->check_substr : prog->check_utf8);
            prog->check_substr = prog->check_utf8 = NULL;       /* disable */
            prog->float_substr = prog->float_utf8 = NULL;       /* clear */
            check = NULL;                       /* abort */
@@ -794,7 +997,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
            /* XXXX This is a remnant of the old implementation.  It
                    looks wasteful, since now INTUIT can use many
                    other heuristics. */
-           prog->reganch &= ~RE_USE_INTUIT;
+           prog->extflags &= ~RXf_USE_INTUIT;
        }
        else
            s = strpos;
@@ -802,7 +1005,9 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 
     /* Last resort... */
     /* XXXX BmUSEFUL already changed, maybe multiple change is meaningful... */
-    if (prog->regstclass) {
+    /* trie stclasses are too expensive to use here, we are better off to
+       leave it to regmatch itself */
+    if (progi->regstclass && PL_regkind[OP(progi->regstclass)]!=TRIE) {
        /* minlen == 0 is possible if regstclass is \b or \B,
           and the fixed substr is ''$.
           Since minlen is already taken into account, s+1 is before strend;
@@ -811,19 +1016,23 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
           regstclass does not come from lookahead...  */
        /* If regstclass takes bytelength more than 1: If charlength==1, OK.
           This leaves EXACTF only, which is dealt with in find_byclass().  */
-        const U8* const str = (U8*)STRING(prog->regstclass);
-        const int cl_l = (PL_regkind[(U8)OP(prog->regstclass)] == EXACT
-                   ? CHR_DIST(str+STR_LEN(prog->regstclass), str)
+        const U8* const str = (U8*)STRING(progi->regstclass);
+        const int cl_l = (PL_regkind[OP(progi->regstclass)] == EXACT
+                   ? CHR_DIST(str+STR_LEN(progi->regstclass), str)
                    : 1);
-       const char * const endpos = (prog->anchored_substr || prog->anchored_utf8 || ml_anch)
-               ? HOP3c(s, (prog->minlen ? cl_l : 0), strend)
-               : (prog->float_substr || prog->float_utf8
-                  ? HOP3c(HOP3c(check_at, -start_shift, strbeg),
-                          cl_l, strend)
-                  : strend);
-
+       char * endpos;
+       if (prog->anchored_substr || prog->anchored_utf8 || ml_anch)
+            endpos= HOP3c(s, (prog->minlen ? cl_l : 0), strend);
+        else if (prog->float_substr || prog->float_utf8)
+           endpos= HOP3c(HOP3c(check_at, -start_shift, strbeg), cl_l, strend);
+        else 
+            endpos= strend;
+                   
+        DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "start_shift: %"IVdf" check_at: %"IVdf" s: %"IVdf" endpos: %"IVdf"\n",
+                                     (IV)start_shift, (IV)(check_at - strbeg), (IV)(s - strbeg), (IV)(endpos - strbeg)));
+       
        t = s;
-        s = find_byclass(prog, prog->regstclass, s, endpos, NULL);
+        s = find_byclass(prog, progi->regstclass, s, endpos, NULL);
        if (!s) {
 #ifdef DEBUGGING
            const char *what = NULL;
@@ -835,11 +1044,11 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
            }
            DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
                                   "This position contradicts STCLASS...\n") );
-           if ((prog->reganch & ROPT_ANCH) && !ml_anch)
+           if ((prog->extflags & RXf_ANCH) && !ml_anch)
                goto fail;
            /* Contradict one of substrings */
            if (prog->anchored_substr || prog->anchored_utf8) {
-               if ((do_utf8 ? prog->anchored_utf8 : prog->anchored_substr) == check) {
+               if ((utf8_target ? prog->anchored_utf8 : prog->anchored_substr) == check) {
                    DEBUG_EXECUTE_r( what = "anchored" );
                  hop_and_restart:
                    s = HOP3c(t, 1, strend);
@@ -879,7 +1088,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                          PL_colors[0], PL_colors[1], (long)(t - i_strpos)) );
                goto try_at_offset;
            }
-           if (!(do_utf8 ? prog->float_utf8 : prog->float_substr))     /* Could have been deleted */
+           if (!(utf8_target ? prog->float_utf8 : prog->float_substr)) /* Could have been deleted */
                goto fail;
            /* Check is floating subtring. */
          retry_floating_check:
@@ -907,22 +1116,193 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 
   fail_finish:                         /* Substring not found */
     if (prog->check_substr || prog->check_utf8)                /* could be removed already */
-       BmUSEFUL(do_utf8 ? prog->check_utf8 : prog->check_substr) += 5; /* hooray */
+       BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr) += 5; /* hooray */
   fail:
     DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch rejected by optimizer%s\n",
                          PL_colors[4], PL_colors[5]));
     return NULL;
 }
 
+#define DECL_TRIE_TYPE(scan) \
+    const enum { trie_plain, trie_utf8, trie_utf8_fold, trie_latin_utf8_fold } \
+                   trie_type = (scan->flags != EXACT) \
+                             ? (utf8_target ? trie_utf8_fold : (UTF_PATTERN ? trie_latin_utf8_fold : trie_plain)) \
+                              : (utf8_target ? trie_utf8 : trie_plain)
+
+#define REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc, uscan, len,  \
+uvc, charid, foldlen, foldbuf, uniflags) STMT_START {                       \
+    switch (trie_type) {                                                    \
+    case trie_utf8_fold:                                                    \
+       if ( foldlen>0 ) {                                                  \
+           uvc = utf8n_to_uvuni( uscan, UTF8_MAXLEN, &len, uniflags ); \
+           foldlen -= len;                                                 \
+           uscan += len;                                                   \
+           len=0;                                                          \
+       } else {                                                            \
+           uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN, &len, uniflags ); \
+           uvc = to_uni_fold( uvc, foldbuf, &foldlen );                    \
+           foldlen -= UNISKIP( uvc );                                      \
+           uscan = foldbuf + UNISKIP( uvc );                               \
+       }                                                                   \
+       break;                                                              \
+    case trie_latin_utf8_fold:                                              \
+       if ( foldlen>0 ) {                                                  \
+           uvc = utf8n_to_uvuni( uscan, UTF8_MAXLEN, &len, uniflags );     \
+           foldlen -= len;                                                 \
+           uscan += len;                                                   \
+           len=0;                                                          \
+       } else {                                                            \
+           len = 1;                                                        \
+           uvc = to_uni_fold( *(U8*)uc, foldbuf, &foldlen );               \
+           foldlen -= UNISKIP( uvc );                                      \
+           uscan = foldbuf + UNISKIP( uvc );                               \
+       }                                                                   \
+       break;                                                              \
+    case trie_utf8:                                                         \
+       uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN, &len, uniflags );       \
+       break;                                                              \
+    case trie_plain:                                                        \
+       uvc = (UV)*uc;                                                      \
+       len = 1;                                                            \
+    }                                                                       \
+    if (uvc < 256) {                                                        \
+       charid = trie->charmap[ uvc ];                                      \
+    }                                                                       \
+    else {                                                                  \
+       charid = 0;                                                         \
+       if (widecharmap) {                                                  \
+           SV** const svpp = hv_fetch(widecharmap,                         \
+                       (char*)&uvc, sizeof(UV), 0);                        \
+           if (svpp)                                                       \
+               charid = (U16)SvIV(*svpp);                                  \
+       }                                                                   \
+    }                                                                       \
+} STMT_END
+
+#define REXEC_FBC_EXACTISH_CHECK(CoNd)                 \
+{                                                      \
+    char *my_strend= (char *)strend;                   \
+    if ( (CoNd)                                        \
+        && (ln == len ||                              \
+            foldEQ_utf8(s, &my_strend, 0,  utf8_target,   \
+                       m, NULL, ln, cBOOL(UTF_PATTERN)))      \
+        && (!reginfo || regtry(reginfo, &s)) )        \
+       goto got_it;                                   \
+    else {                                             \
+        U8 foldbuf[UTF8_MAXBYTES_CASE+1];             \
+        uvchr_to_utf8(tmpbuf, c);                     \
+        f = to_utf8_fold(tmpbuf, foldbuf, &foldlen);  \
+        if ( f != c                                   \
+             && (f == c1 || f == c2)                  \
+             && (ln == len ||                         \
+               foldEQ_utf8(s, &my_strend, 0,  utf8_target,\
+                             m, NULL, ln, cBOOL(UTF_PATTERN)))\
+             && (!reginfo || regtry(reginfo, &s)) )   \
+             goto got_it;                             \
+    }                                                  \
+}                                                      \
+s += len
+
+#define REXEC_FBC_EXACTISH_SCAN(CoNd)                     \
+STMT_START {                                              \
+    while (s <= e) {                                      \
+       if ( (CoNd)                                       \
+            && (ln == 1 || (OP(c) == EXACTF             \
+                             ? foldEQ(s, m, ln)           \
+                             : foldEQ_locale(s, m, ln)))  \
+            && (!reginfo || regtry(reginfo, &s)) )        \
+           goto got_it;                                  \
+       s++;                                              \
+    }                                                     \
+} STMT_END
+
+#define REXEC_FBC_UTF8_SCAN(CoDe)                     \
+STMT_START {                                          \
+    while (s + (uskip = UTF8SKIP(s)) <= strend) {     \
+       CoDe                                          \
+       s += uskip;                                   \
+    }                                                 \
+} STMT_END
+
+#define REXEC_FBC_SCAN(CoDe)                          \
+STMT_START {                                          \
+    while (s < strend) {                              \
+       CoDe                                          \
+       s++;                                          \
+    }                                                 \
+} STMT_END
+
+#define REXEC_FBC_UTF8_CLASS_SCAN(CoNd)               \
+REXEC_FBC_UTF8_SCAN(                                  \
+    if (CoNd) {                                       \
+       if (tmp && (!reginfo || regtry(reginfo, &s)))  \
+           goto got_it;                              \
+       else                                          \
+           tmp = doevery;                            \
+    }                                                 \
+    else                                              \
+       tmp = 1;                                      \
+)
+
+#define REXEC_FBC_CLASS_SCAN(CoNd)                    \
+REXEC_FBC_SCAN(                                       \
+    if (CoNd) {                                       \
+       if (tmp && (!reginfo || regtry(reginfo, &s)))  \
+           goto got_it;                              \
+       else                                          \
+           tmp = doevery;                            \
+    }                                                 \
+    else                                              \
+       tmp = 1;                                      \
+)
+
+#define REXEC_FBC_TRYIT               \
+if ((!reginfo || regtry(reginfo, &s))) \
+    goto got_it
+
+#define REXEC_FBC_CSCAN(CoNdUtF8,CoNd)                         \
+    if (utf8_target) {                                             \
+       REXEC_FBC_UTF8_CLASS_SCAN(CoNdUtF8);                   \
+    }                                                          \
+    else {                                                     \
+       REXEC_FBC_CLASS_SCAN(CoNd);                            \
+    }                                                          \
+    break
+    
+#define REXEC_FBC_CSCAN_PRELOAD(UtFpReLoAd,CoNdUtF8,CoNd)      \
+    if (utf8_target) {                                             \
+       UtFpReLoAd;                                            \
+       REXEC_FBC_UTF8_CLASS_SCAN(CoNdUtF8);                   \
+    }                                                          \
+    else {                                                     \
+       REXEC_FBC_CLASS_SCAN(CoNd);                            \
+    }                                                          \
+    break
+
+#define REXEC_FBC_CSCAN_TAINT(CoNdUtF8,CoNd)                   \
+    PL_reg_flags |= RF_tainted;                                \
+    if (utf8_target) {                                             \
+       REXEC_FBC_UTF8_CLASS_SCAN(CoNdUtF8);                   \
+    }                                                          \
+    else {                                                     \
+       REXEC_FBC_CLASS_SCAN(CoNd);                            \
+    }                                                          \
+    break
+
+#define DUMP_EXEC_POS(li,s,doutf8) \
+    dump_exec_pos(li,s,(PL_regeol),(PL_bostr),(PL_reg_starttry),doutf8)
+
 /* We know what class REx starts with.  Try to find this position... */
 /* if reginfo is NULL, its a dryrun */
+/* annoyingly all the vars in this routine have different names from their counterparts
+   in regmatch. /grrr */
 
 STATIC char *
-S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
-*strend, const regmatch_info *reginfo)
+S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, 
+    const char *strend, regmatch_info *reginfo)
 {
        dVAR;
-       const I32 doevery = (prog->reganch & ROPT_SKIP) == 0;
+       const I32 doevery = (prog->intflags & PREGf_SKIP) == 0;
        char *m;
        STRLEN ln;
        STRLEN lnc;
@@ -931,26 +1311,19 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
        unsigned int c2;
        char *e;
        register I32 tmp = 1;   /* Scratch variable? */
-       register const bool do_utf8 = PL_reg_match_utf8;
+       register const bool utf8_target = PL_reg_match_utf8;
+        RXi_GET_DECL(prog,progi);
 
+       PERL_ARGS_ASSERT_FIND_BYCLASS;
+        
        /* We know what class it must start with. */
        switch (OP(c)) {
        case ANYOF:
-           if (do_utf8) {
-                while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                     if ((ANYOF_FLAGS(c) & ANYOF_UNICODE) ||
+           if (utf8_target) {
+                REXEC_FBC_UTF8_CLASS_SCAN((ANYOF_FLAGS(c) & ANYOF_UNICODE) ||
                          !UTF8_IS_INVARIANT((U8)s[0]) ?
-                         reginclass(prog, c, (U8*)s, 0, do_utf8) :
-                         REGINCLASS(prog, c, (U8*)s)) {
-                          if (tmp && (!reginfo || regtry(reginfo, s)))
-                               goto got_it;
-                          else
-                               tmp = doevery;
-                     }
-                     else 
-                          tmp = 1;
-                     s += uskip;
-                }
+                         reginclass(prog, c, (U8*)s, 0, utf8_target) :
+                         REGINCLASS(prog, c, (U8*)s));
            }
            else {
                 while (s < strend) {
@@ -961,7 +1334,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
                           /* The assignment of 2 is intentional:
                            * for the folded sharp s, the skip is 2. */
                           (skip = SHARP_S_SKIP))) {
-                          if (tmp && (!reginfo || regtry(reginfo, s)))
+                          if (tmp && (!reginfo || regtry(reginfo, &s)))
                                goto got_it;
                           else
                                tmp = doevery;
@@ -973,32 +1346,44 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
            }
            break;
        case CANY:
-           while (s < strend) {
-               if (tmp && (!reginfo || regtry(reginfo, s)))
+           REXEC_FBC_SCAN(
+               if (tmp && (!reginfo || regtry(reginfo, &s)))
                    goto got_it;
                else
                    tmp = doevery;
-               s++;
-           }
+           );
            break;
        case EXACTF:
            m   = STRING(c);
            ln  = STR_LEN(c);   /* length to match in octets/bytes */
            lnc = (I32) ln;     /* length to match in characters */
-           if (UTF) {
+           if (UTF_PATTERN) {
                STRLEN ulen1, ulen2;
                U8 *sm = (U8 *) m;
                U8 tmpbuf1[UTF8_MAXBYTES_CASE+1];
                U8 tmpbuf2[UTF8_MAXBYTES_CASE+1];
-               const U32 uniflags = UTF8_ALLOW_DEFAULT;
-
-               to_utf8_lower((U8*)m, tmpbuf1, &ulen1);
-               to_utf8_upper((U8*)m, tmpbuf2, &ulen2);
-
+               /* used by commented-out code below */
+               /*const U32 uniflags = UTF8_ALLOW_DEFAULT;*/
+               
+                /* XXX: Since the node will be case folded at compile
+                   time this logic is a little odd, although im not 
+                   sure that its actually wrong. --dmq */
+                   
+               c1 = to_utf8_lower((U8*)m, tmpbuf1, &ulen1);
+               c2 = to_utf8_upper((U8*)m, tmpbuf2, &ulen2);
+
+               /* XXX: This is kinda strange. to_utf8_XYZ returns the 
+                   codepoint of the first character in the converted
+                   form, yet originally we did the extra step. 
+                   No tests fail by commenting this code out however
+                   so Ive left it out. -- dmq.
+                   
                c1 = utf8n_to_uvchr(tmpbuf1, UTF8_MAXBYTES_CASE, 
                                    0, uniflags);
                c2 = utf8n_to_uvchr(tmpbuf2, UTF8_MAXBYTES_CASE,
                                    0, uniflags);
+                */
+                
                lnc = 0;
                while (sm < ((U8 *) m + ln)) {
                    lnc++;
@@ -1031,46 +1416,35 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
             * than just upper and lower: one needs to use
             * the so-called folding case for case-insensitive
             * matching (called "loose matching" in Unicode).
-            * ibcmp_utf8() will do just that. */
+            * foldEQ_utf8() will do just that. */
 
-           if (do_utf8) {
+           if (utf8_target || UTF_PATTERN) {
                UV c, f;
                U8 tmpbuf [UTF8_MAXBYTES+1];
-               STRLEN len, foldlen;
+               STRLEN len = 1;
+               STRLEN foldlen;
                const U32 uniflags = UTF8_ALLOW_DEFAULT;
                if (c1 == c2) {
                    /* Upper and lower of 1st char are equal -
                     * probably not a "letter". */
                    while (s <= e) {
-                       c = utf8n_to_uvchr((U8*)s, UTF8_MAXBYTES, &len,
+                       if (utf8_target) {
+                           c = utf8n_to_uvchr((U8*)s, UTF8_MAXBYTES, &len,
                                           uniflags);
-                       if ( c == c1
-                            && (ln == len ||
-                                ibcmp_utf8(s, (char **)0, 0,  do_utf8,
-                                           m, (char **)0, ln, (bool)UTF))
-                            && (!reginfo || regtry(reginfo, s)) )
-                           goto got_it;
-                       else {
-                            U8 foldbuf[UTF8_MAXBYTES_CASE+1];
-                            uvchr_to_utf8(tmpbuf, c);
-                            f = to_utf8_fold(tmpbuf, foldbuf, &foldlen);
-                            if ( f != c
-                                 && (f == c1 || f == c2)
-                                 && (ln == foldlen ||
-                                     !ibcmp_utf8((char *) foldbuf,
-                                                 (char **)0, foldlen, do_utf8,
-                                                 m,
-                                                 (char **)0, ln, (bool)UTF))
-                                 && (!reginfo || regtry(reginfo, s)) )
-                                 goto got_it;
-                       }
-                       s += len;
+                        } else {
+                            c = *((U8*)s);
+                        }                                        
+                       REXEC_FBC_EXACTISH_CHECK(c == c1);
                    }
                }
                else {
                    while (s <= e) {
-                     c = utf8n_to_uvchr((U8*)s, UTF8_MAXBYTES, &len,
+                       if (utf8_target) {
+                           c = utf8n_to_uvchr((U8*)s, UTF8_MAXBYTES, &len,
                                           uniflags);
+                        } else {
+                            c = *((U8*)s);
+                        }
 
                        /* Handle some of the three Greek sigmas cases.
                         * Note that not all the possible combinations
@@ -1083,58 +1457,23 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
                            c == (UV)UNICODE_GREEK_SMALL_LETTER_FINAL_SIGMA)
                            c = (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA;
 
-                       if ( (c == c1 || c == c2)
-                            && (ln == len ||
-                                ibcmp_utf8(s, (char **)0, 0,  do_utf8,
-                                           m, (char **)0, ln, (bool)UTF))
-                            && (!reginfo || regtry(reginfo, s)) )
-                           goto got_it;
-                       else {
-                            U8 foldbuf[UTF8_MAXBYTES_CASE+1];
-                            uvchr_to_utf8(tmpbuf, c);
-                            f = to_utf8_fold(tmpbuf, foldbuf, &foldlen);
-                            if ( f != c
-                                 && (f == c1 || f == c2)
-                                 && (ln == foldlen ||
-                                     !ibcmp_utf8((char *) foldbuf,
-                                                 (char **)0, foldlen, do_utf8,
-                                                 m,
-                                                 (char **)0, ln, (bool)UTF))
-                                 && (!reginfo || regtry(reginfo, s)) )
-                                 goto got_it;
-                       }
-                       s += len;
+                       REXEC_FBC_EXACTISH_CHECK(c == c1 || c == c2);
                    }
                }
            }
            else {
+               /* Neither pattern nor string are UTF8 */
                if (c1 == c2)
-                   while (s <= e) {
-                       if ( *(U8*)s == c1
-                            && (ln == 1 || !(OP(c) == EXACTF
-                                             ? ibcmp(s, m, ln)
-                                             : ibcmp_locale(s, m, ln)))
-                            && (!reginfo || regtry(reginfo, s)) )
-                           goto got_it;
-                       s++;
-                   }
+                   REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1);
                else
-                   while (s <= e) {
-                       if ( (*(U8*)s == c1 || *(U8*)s == c2)
-                            && (ln == 1 || !(OP(c) == EXACTF
-                                             ? ibcmp(s, m, ln)
-                                             : ibcmp_locale(s, m, ln)))
-                            && (!reginfo || regtry(reginfo, s)) )
-                           goto got_it;
-                       s++;
-                   }
+                   REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1 || *(U8*)s == c2);
            }
            break;
        case BOUNDL:
            PL_reg_flags |= RF_tainted;
            /* FALL THROUGH */
        case BOUND:
-           if (do_utf8) {
+           if (utf8_target) {
                if (s == PL_bostr)
                    tmp = '\n';
                else {
@@ -1144,39 +1483,35 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
                tmp = ((OP(c) == BOUND ?
                        isALNUM_uni(tmp) : isALNUM_LC_uvchr(UNI_TO_NATIVE(tmp))) != 0);
                LOAD_UTF8_CHARCLASS_ALNUM();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
+               REXEC_FBC_UTF8_SCAN(
                    if (tmp == !(OP(c) == BOUND ?
-                                swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8) :
+                                cBOOL(swash_fetch(PL_utf8_alnum, (U8*)s, utf8_target)) :
                                 isALNUM_LC_utf8((U8*)s)))
                    {
                        tmp = !tmp;
-                       if ((!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                   }
-                   s += uskip;
+                       REXEC_FBC_TRYIT;
                }
+               );
            }
            else {
                tmp = (s != PL_bostr) ? UCHARAT(s - 1) : '\n';
                tmp = ((OP(c) == BOUND ? isALNUM(tmp) : isALNUM_LC(tmp)) != 0);
-               while (s < strend) {
+               REXEC_FBC_SCAN(
                    if (tmp ==
                        !(OP(c) == BOUND ? isALNUM(*s) : isALNUM_LC(*s))) {
                        tmp = !tmp;
-                       if ((!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                   }
-                   s++;
+                       REXEC_FBC_TRYIT;
                }
+               );
            }
-           if ((!prog->minlen && tmp) && (!reginfo || regtry(reginfo, s)))
+           if ((!prog->minlen && tmp) && (!reginfo || regtry(reginfo, &s)))
                goto got_it;
            break;
        case NBOUNDL:
            PL_reg_flags |= RF_tainted;
            /* FALL THROUGH */
        case NBOUND:
-           if (do_utf8) {
+           if (utf8_target) {
                if (s == PL_bostr)
                    tmp = '\n';
                else {
@@ -1186,378 +1521,326 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
                tmp = ((OP(c) == NBOUND ?
                        isALNUM_uni(tmp) : isALNUM_LC_uvchr(UNI_TO_NATIVE(tmp))) != 0);
                LOAD_UTF8_CHARCLASS_ALNUM();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
+               REXEC_FBC_UTF8_SCAN(
                    if (tmp == !(OP(c) == NBOUND ?
-                                swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8) :
+                                cBOOL(swash_fetch(PL_utf8_alnum, (U8*)s, utf8_target)) :
                                 isALNUM_LC_utf8((U8*)s)))
                        tmp = !tmp;
-                   else if ((!reginfo || regtry(reginfo, s)))
-                       goto got_it;
-                   s += uskip;
-               }
+                   else REXEC_FBC_TRYIT;
+               );
            }
            else {
                tmp = (s != PL_bostr) ? UCHARAT(s - 1) : '\n';
                tmp = ((OP(c) == NBOUND ?
                        isALNUM(tmp) : isALNUM_LC(tmp)) != 0);
-               while (s < strend) {
+               REXEC_FBC_SCAN(
                    if (tmp ==
                        !(OP(c) == NBOUND ? isALNUM(*s) : isALNUM_LC(*s)))
                        tmp = !tmp;
-                   else if ((!reginfo || regtry(reginfo, s)))
-                       goto got_it;
-                   s++;
-               }
+                   else REXEC_FBC_TRYIT;
+               );
            }
-           if ((!prog->minlen && !tmp) && (!reginfo || regtry(reginfo, s)))
+           if ((!prog->minlen && !tmp) && (!reginfo || regtry(reginfo, &s)))
                goto got_it;
            break;
        case ALNUM:
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_ALNUM();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (isALNUM(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_PRELOAD(
+               LOAD_UTF8_CHARCLASS_PERL_WORD(),
+               swash_fetch(RE_utf8_perl_word, (U8*)s, utf8_target),
+               isALNUM(*s)
+           );
        case ALNUML:
-           PL_reg_flags |= RF_tainted;
-           if (do_utf8) {
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (isALNUM_LC_utf8((U8*)s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (isALNUM_LC(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_TAINT(
+               isALNUM_LC_utf8((U8*)s),
+               isALNUM_LC(*s)
+           );
        case NALNUM:
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_ALNUM();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (!swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (!isALNUM(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_PRELOAD(
+               LOAD_UTF8_CHARCLASS_PERL_WORD(),
+               !swash_fetch(RE_utf8_perl_word, (U8*)s, utf8_target),
+               !isALNUM(*s)
+           );
        case NALNUML:
-           PL_reg_flags |= RF_tainted;
-           if (do_utf8) {
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (!isALNUM_LC_utf8((U8*)s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (!isALNUM_LC(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_TAINT(
+               !isALNUM_LC_utf8((U8*)s),
+               !isALNUM_LC(*s)
+           );
        case SPACE:
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_SPACE();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (*s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, do_utf8)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (isSPACE(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_PRELOAD(
+               LOAD_UTF8_CHARCLASS_PERL_SPACE(),
+               *s == ' ' || swash_fetch(RE_utf8_perl_space,(U8*)s, utf8_target),
+               isSPACE(*s)
+           );
        case SPACEL:
-           PL_reg_flags |= RF_tainted;
-           if (do_utf8) {
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (*s == ' ' || isSPACE_LC_utf8((U8*)s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (isSPACE_LC(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_TAINT(
+               *s == ' ' || isSPACE_LC_utf8((U8*)s),
+               isSPACE_LC(*s)
+           );
        case NSPACE:
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_SPACE();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (!(*s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, do_utf8))) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (!isSPACE(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_PRELOAD(
+               LOAD_UTF8_CHARCLASS_PERL_SPACE(),
+               !(*s == ' ' || swash_fetch(RE_utf8_perl_space,(U8*)s, utf8_target)),
+               !isSPACE(*s)
+           );
        case NSPACEL:
-           PL_reg_flags |= RF_tainted;
-           if (do_utf8) {
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (!(*s == ' ' || isSPACE_LC_utf8((U8*)s))) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (!isSPACE_LC(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_TAINT(
+               !(*s == ' ' || isSPACE_LC_utf8((U8*)s)),
+               !isSPACE_LC(*s)
+           );
        case DIGIT:
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_DIGIT();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (swash_fetch(PL_utf8_digit,(U8*)s, do_utf8)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (isDIGIT(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_PRELOAD(
+               LOAD_UTF8_CHARCLASS_POSIX_DIGIT(),
+               swash_fetch(RE_utf8_posix_digit,(U8*)s, utf8_target),
+               isDIGIT(*s)
+           );
        case DIGITL:
-           PL_reg_flags |= RF_tainted;
-           if (do_utf8) {
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (isDIGIT_LC_utf8((U8*)s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (isDIGIT_LC(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_TAINT(
+               isDIGIT_LC_utf8((U8*)s),
+               isDIGIT_LC(*s)
+           );
        case NDIGIT:
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_DIGIT();
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (!swash_fetch(PL_utf8_digit,(U8*)s, do_utf8)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (!isDIGIT(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
-           }
-           break;
+           REXEC_FBC_CSCAN_PRELOAD(
+               LOAD_UTF8_CHARCLASS_POSIX_DIGIT(),
+               !swash_fetch(RE_utf8_posix_digit,(U8*)s, utf8_target),
+               !isDIGIT(*s)
+           );
        case NDIGITL:
-           PL_reg_flags |= RF_tainted;
-           if (do_utf8) {
-               while (s + (uskip = UTF8SKIP(s)) <= strend) {
-                   if (!isDIGIT_LC_utf8((U8*)s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s += uskip;
-               }
-           }
-           else {
-               while (s < strend) {
-                   if (!isDIGIT_LC(*s)) {
-                       if (tmp && (!reginfo || regtry(reginfo, s)))
-                           goto got_it;
-                       else
-                           tmp = doevery;
-                   }
-                   else
-                       tmp = 1;
-                   s++;
-               }
+           REXEC_FBC_CSCAN_TAINT(
+               !isDIGIT_LC_utf8((U8*)s),
+               !isDIGIT_LC(*s)
+           );
+       case LNBREAK:
+           REXEC_FBC_CSCAN(
+               is_LNBREAK_utf8(s),
+               is_LNBREAK_latin1(s)
+           );
+       case VERTWS:
+           REXEC_FBC_CSCAN(
+               is_VERTWS_utf8(s),
+               is_VERTWS_latin1(s)
+           );
+       case NVERTWS:
+           REXEC_FBC_CSCAN(
+               !is_VERTWS_utf8(s),
+               !is_VERTWS_latin1(s)
+           );
+       case HORIZWS:
+           REXEC_FBC_CSCAN(
+               is_HORIZWS_utf8(s),
+               is_HORIZWS_latin1(s)
+           );
+       case NHORIZWS:
+           REXEC_FBC_CSCAN(
+               !is_HORIZWS_utf8(s),
+               !is_HORIZWS_latin1(s)
+           );      
+       case AHOCORASICKC:
+       case AHOCORASICK: 
+           {
+               DECL_TRIE_TYPE(c);
+                /* what trie are we using right now */
+               reg_ac_data *aho
+                   = (reg_ac_data*)progi->data->data[ ARG( c ) ];
+               reg_trie_data *trie
+                   = (reg_trie_data*)progi->data->data[ aho->trie ];
+               HV *widecharmap = MUTABLE_HV(progi->data->data[ aho->trie + 1 ]);
+
+               const char *last_start = strend - trie->minlen;
+#ifdef DEBUGGING
+               const char *real_start = s;
+#endif
+               STRLEN maxlen = trie->maxlen;
+               SV *sv_points;
+               U8 **points; /* map of where we were in the input string
+                               when reading a given char. For ASCII this
+                               is unnecessary overhead as the relationship
+                               is always 1:1, but for Unicode, especially
+                               case folded Unicode this is not true. */
+               U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
+               U8 *bitmap=NULL;
+
+
+                GET_RE_DEBUG_FLAGS_DECL;
+
+                /* We can't just allocate points here. We need to wrap it in
+                 * an SV so it gets freed properly if there is a croak while
+                 * running the match */
+                ENTER;
+               SAVETMPS;
+                sv_points=newSV(maxlen * sizeof(U8 *));
+                SvCUR_set(sv_points,
+                    maxlen * sizeof(U8 *));
+                SvPOK_on(sv_points);
+                sv_2mortal(sv_points);
+                points=(U8**)SvPV_nolen(sv_points );
+                if ( trie_type != trie_utf8_fold 
+                     && (trie->bitmap || OP(c)==AHOCORASICKC) ) 
+                {
+                    if (trie->bitmap) 
+                        bitmap=(U8*)trie->bitmap;
+                    else
+                        bitmap=(U8*)ANYOF_BITMAP(c);
+                }
+                /* this is the Aho-Corasick algorithm modified a touch
+                   to include special handling for long "unknown char" 
+                   sequences. The basic idea being that we use AC as long
+                   as we are dealing with a possible matching char, when
+                   we encounter an unknown char (and we have not encountered
+                   an accepting state) we scan forward until we find a legal 
+                   starting char. 
+                   AC matching is basically that of trie matching, except
+                   that when we encounter a failing transition, we fall back
+                   to the current states "fail state", and try the current char 
+                   again, a process we repeat until we reach the root state, 
+                   state 1, or a legal transition. If we fail on the root state 
+                   then we can either terminate if we have reached an accepting 
+                   state previously, or restart the entire process from the beginning 
+                   if we have not.
+
+                 */
+                while (s <= last_start) {
+                    const U32 uniflags = UTF8_ALLOW_DEFAULT;
+                    U8 *uc = (U8*)s;
+                    U16 charid = 0;
+                    U32 base = 1;
+                    U32 state = 1;
+                    UV uvc = 0;
+                    STRLEN len = 0;
+                    STRLEN foldlen = 0;
+                    U8 *uscan = (U8*)NULL;
+                    U8 *leftmost = NULL;
+#ifdef DEBUGGING                    
+                    U32 accepted_word= 0;
+#endif
+                    U32 pointpos = 0;
+
+                    while ( state && uc <= (U8*)strend ) {
+                        int failed=0;
+                        U32 word = aho->states[ state ].wordnum;
+
+                        if( state==1 ) {
+                            if ( bitmap ) {
+                                DEBUG_TRIE_EXECUTE_r(
+                                    if ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
+                                        dump_exec_pos( (char *)uc, c, strend, real_start, 
+                                            (char *)uc, utf8_target );
+                                        PerlIO_printf( Perl_debug_log,
+                                            " Scanning for legal start char...\n");
+                                    }
+                                );            
+                                while ( uc <= (U8*)last_start  && !BITMAP_TEST(bitmap,*uc) ) {
+                                    uc++;
+                                }
+                                s= (char *)uc;
+                            }
+                            if (uc >(U8*)last_start) break;
+                        }
+                                            
+                        if ( word ) {
+                            U8 *lpos= points[ (pointpos - trie->wordinfo[word].len) % maxlen ];
+                            if (!leftmost || lpos < leftmost) {
+                                DEBUG_r(accepted_word=word);
+                                leftmost= lpos;
+                            }
+                            if (base==0) break;
+                            
+                        }
+                        points[pointpos++ % maxlen]= uc;
+                       REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc,
+                                            uscan, len, uvc, charid, foldlen,
+                                            foldbuf, uniflags);
+                        DEBUG_TRIE_EXECUTE_r({
+                            dump_exec_pos( (char *)uc, c, strend, real_start, 
+                                s,   utf8_target );
+                            PerlIO_printf(Perl_debug_log,
+                                " Charid:%3u CP:%4"UVxf" ",
+                                 charid, uvc);
+                        });
+
+                        do {
+#ifdef DEBUGGING
+                            word = aho->states[ state ].wordnum;
+#endif
+                            base = aho->states[ state ].trans.base;
+
+                            DEBUG_TRIE_EXECUTE_r({
+                                if (failed) 
+                                    dump_exec_pos( (char *)uc, c, strend, real_start, 
+                                        s,   utf8_target );
+                                PerlIO_printf( Perl_debug_log,
+                                    "%sState: %4"UVxf", word=%"UVxf,
+                                    failed ? " Fail transition to " : "",
+                                    (UV)state, (UV)word);
+                            });
+                            if ( base ) {
+                                U32 tmp;
+                               I32 offset;
+                                if (charid &&
+                                    ( ((offset = base + charid
+                                       - 1 - trie->uniquecharcount)) >= 0)
+                                     && ((U32)offset < trie->lasttrans)
+                                     && trie->trans[offset].check == state
+                                     && (tmp=trie->trans[offset].next))
+                                {
+                                    DEBUG_TRIE_EXECUTE_r(
+                                        PerlIO_printf( Perl_debug_log," - legal\n"));
+                                    state = tmp;
+                                    break;
+                                }
+                                else {
+                                    DEBUG_TRIE_EXECUTE_r(
+                                        PerlIO_printf( Perl_debug_log," - fail\n"));
+                                    failed = 1;
+                                    state = aho->fail[state];
+                                }
+                            }
+                            else {
+                                /* we must be accepting here */
+                                DEBUG_TRIE_EXECUTE_r(
+                                        PerlIO_printf( Perl_debug_log," - accepting\n"));
+                                failed = 1;
+                                break;
+                            }
+                        } while(state);
+                        uc += len;
+                        if (failed) {
+                            if (leftmost)
+                                break;
+                            if (!state) state = 1;
+                        }
+                    }
+                    if ( aho->states[ state ].wordnum ) {
+                        U8 *lpos = points[ (pointpos - trie->wordinfo[aho->states[ state ].wordnum].len) % maxlen ];
+                        if (!leftmost || lpos < leftmost) {
+                            DEBUG_r(accepted_word=aho->states[ state ].wordnum);
+                            leftmost = lpos;
+                        }
+                    }
+                    if (leftmost) {
+                        s = (char*)leftmost;
+                        DEBUG_TRIE_EXECUTE_r({
+                            PerlIO_printf( 
+                                Perl_debug_log,"Matches word #%"UVxf" at position %"IVdf". Trying full pattern...\n",
+                                (UV)accepted_word, (IV)(s - real_start)
+                            );
+                        });
+                        if (!reginfo || regtry(reginfo, &s)) {
+                            FREETMPS;
+                           LEAVE;
+                            goto got_it;
+                        }
+                        s = HOPc(s,1);
+                        DEBUG_TRIE_EXECUTE_r({
+                            PerlIO_printf( Perl_debug_log,"Pattern failed. Looking for new start point...\n");
+                        });
+                    } else {
+                        DEBUG_TRIE_EXECUTE_r(
+                            PerlIO_printf( Perl_debug_log,"No match.\n"));
+                        break;
+                    }
+                }
+                FREETMPS;
+                LEAVE;
            }
            break;
        default:
@@ -1569,38 +1852,39 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
        return s;
 }
 
+
 /*
  - regexec_flags - match a regexp against a string
  */
 I32
-Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *strend,
+Perl_regexec_flags(pTHX_ REGEXP * const rx, char *stringarg, register char *strend,
              char *strbeg, I32 minend, SV *sv, void *data, U32 flags)
 /* strend: pointer to null at end of string */
 /* strbeg: real beginning of string */
 /* minend: end of match must be >=minend after stringarg. */
-/* data: May be used for some additional optimizations. */
+/* data: May be used for some additional optimizations. 
+         Currently its only used, with a U32 cast, for transmitting 
+         the ganch offset when doing a /g match. This will change */
 /* nosave: For optimizations. */
 {
     dVAR;
-    register char *s;
+    struct regexp *const prog = (struct regexp *)SvANY(rx);
+    /*register*/ char *s;
     register regnode *c;
-    register char *startpos = stringarg;
+    /*register*/ char *startpos = stringarg;
     I32 minlen;                /* must match at least this many chars */
     I32 dontbother = 0;        /* how many characters not to try at end */
     I32 end_shift = 0;                 /* Same for the end. */         /* CC */
     I32 scream_pos = -1;               /* Internal iterator of scream. */
     char *scream_olds = NULL;
-    SV* oreplsv = GvSV(PL_replgv);
-    const bool do_utf8 = DO_UTF8(sv);
+    const bool utf8_target = cBOOL(DO_UTF8(sv));
     I32 multiline;
-#ifdef DEBUGGING
-    SV* dsv0;
-    SV* dsv1;
-#endif
+    RXi_GET_DECL(prog,progi);
     regmatch_info reginfo;  /* create some info to pass to regtry etc */
-
+    regexp_paren_pair *swap = NULL;
     GET_RE_DEBUG_FLAGS_DECL;
 
+    PERL_ARGS_ASSERT_REGEXEC_FLAGS;
     PERL_UNUSED_ARG(data);
 
     /* Be paranoid... */
@@ -1609,25 +1893,26 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        return 0;
     }
 
-    multiline = prog->reganch & PMf_MULTILINE;
-    reginfo.prog = prog;
-
-#ifdef DEBUGGING
-    dsv0 = PERL_DEBUG_PAD_ZERO(0);
-    dsv1 = PERL_DEBUG_PAD_ZERO(1);
-#endif
+    multiline = prog->extflags & RXf_PMf_MULTILINE;
+    reginfo.prog = rx;  /* Yes, sorry that this is confusing.  */
 
-    RX_MATCH_UTF8_set(prog, do_utf8);
+    RX_MATCH_UTF8_set(rx, utf8_target);
+    DEBUG_EXECUTE_r( 
+        debug_start_match(rx, utf8_target, startpos, strend,
+        "Matching");
+    );
 
     minlen = prog->minlen;
-    if (strend - startpos < minlen) {
+    
+    if (strend - startpos < (minlen+(prog->check_offset_min<0?prog->check_offset_min:0))) {
         DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
                              "String too short [regexec_flags]...\n"));
        goto phooey;
     }
 
+    
     /* Check validity of program. */
-    if (UCHARAT(prog->program) != REG_MAGIC) {
+    if (UCHARAT(progi->program) != REG_MAGIC) {
        Perl_croak(aTHX_ "corrupted regexp program");
     }
 
@@ -1635,7 +1920,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     PL_reg_eval_set = 0;
     PL_reg_maxiter = 0;
 
-    if (prog->reganch & ROPT_UTF8)
+    if (RX_UTF8(rx))
        PL_reg_flags |= RF_utf8;
 
     /* Mark beginning of line for ^ and lookbehind. */
@@ -1652,69 +1937,74 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     /* If there is a "must appear" string, look for it. */
     s = startpos;
 
-    if (prog->reganch & ROPT_GPOS_SEEN) { /* Need to set reginfo->ganch */
+    if (prog->extflags & RXf_GPOS_SEEN) { /* Need to set reginfo->ganch */
        MAGIC *mg;
-
-       if (flags & REXEC_IGNOREPOS)    /* Means: check only at start */
-           reginfo.ganch = startpos;
-       else if (sv && SvTYPE(sv) >= SVt_PVMG
+       if (flags & REXEC_IGNOREPOS){   /* Means: check only at start */
+           reginfo.ganch = startpos + prog->gofs;
+           DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
+             "GPOS IGNOREPOS: reginfo.ganch = startpos + %"UVxf"\n",(UV)prog->gofs));
+       } else if (sv && SvTYPE(sv) >= SVt_PVMG
                  && SvMAGIC(sv)
                  && (mg = mg_find(sv, PERL_MAGIC_regex_global))
                  && mg->mg_len >= 0) {
            reginfo.ganch = strbeg + mg->mg_len;        /* Defined pos() */
-           if (prog->reganch & ROPT_ANCH_GPOS) {
+           DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
+               "GPOS MAGIC: reginfo.ganch = strbeg + %"IVdf"\n",(IV)mg->mg_len));
+
+           if (prog->extflags & RXf_ANCH_GPOS) {
                if (s > reginfo.ganch)
                    goto phooey;
-               s = reginfo.ganch;
+               s = reginfo.ganch - prog->gofs;
+               DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
+                    "GPOS ANCH_GPOS: s = ganch - %"UVxf"\n",(UV)prog->gofs));
+               if (s < strbeg)
+                   goto phooey;
            }
        }
-       else                            /* pos() not defined */
+       else if (data) {
+           reginfo.ganch = strbeg + PTR2UV(data);
+            DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
+                "GPOS DATA: reginfo.ganch= strbeg + %"UVxf"\n",PTR2UV(data)));
+
+       } else {                                /* pos() not defined */
            reginfo.ganch = strbeg;
+            DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
+                "GPOS: reginfo.ganch = strbeg\n"));
+       }
+    }
+    if (PL_curpm && (PM_GETRE(PL_curpm) == rx)) {
+        /* We have to be careful. If the previous successful match
+           was from this regex we don't want a subsequent partially
+           successful match to clobber the old results.
+           So when we detect this possibility we add a swap buffer
+           to the re, and switch the buffer each match. If we fail
+           we switch it back, otherwise we leave it swapped.
+        */
+        swap = prog->offs;
+        /* do we need a save destructor here for eval dies? */
+        Newxz(prog->offs, (prog->nparens + 1), regexp_paren_pair);
     }
-
     if (!(flags & REXEC_CHECKED) && (prog->check_substr != NULL || prog->check_utf8 != NULL)) {
        re_scream_pos_data d;
 
        d.scream_olds = &scream_olds;
        d.scream_pos = &scream_pos;
-       s = re_intuit_start(prog, sv, s, strend, flags, &d);
+       s = re_intuit_start(rx, sv, s, strend, flags, &d);
        if (!s) {
            DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Not present...\n"));
            goto phooey;        /* not present */
        }
     }
 
-    DEBUG_EXECUTE_r({
-       const char * const s0   = UTF
-           ? pv_uni_display(dsv0, (U8*)prog->precomp, prog->prelen, 60,
-                         UNI_DISPLAY_REGEX)
-           : prog->precomp;
-       const int len0 = UTF ? SvCUR(dsv0) : prog->prelen;
-       const char * const s1 = do_utf8 ? sv_uni_display(dsv1, sv, 60,
-                                              UNI_DISPLAY_REGEX) : startpos;
-       const int len1 = do_utf8 ? SvCUR(dsv1) : strend - startpos;
-        if (!PL_colorset)
-            reginitcolors();
-        PerlIO_printf(Perl_debug_log,
-                      "%sMatching REx%s \"%s%*.*s%s%s\" against \"%s%.*s%s%s\"\n",
-                      PL_colors[4], PL_colors[5], PL_colors[0],
-                      len0, len0, s0,
-                      PL_colors[1],
-                      len0 > 60 ? "..." : "",
-                      PL_colors[0],
-                      (int)(len1 > 60 ? 60 : len1),
-                      s1, PL_colors[1],
-                      (len1 > 60 ? "..." : "")
-             );
-    });
+
 
     /* Simplest case:  anchored match need be tried only once. */
     /*  [unless only anchor is BOL and multiline is set] */
-    if (prog->reganch & (ROPT_ANCH & ~ROPT_ANCH_GPOS)) {
-       if (s == startpos && regtry(&reginfo, startpos))
+    if (prog->extflags & (RXf_ANCH & ~RXf_ANCH_GPOS)) {
+       if (s == startpos && regtry(&reginfo, &startpos))
            goto got_it;
-       else if (multiline || (prog->reganch & ROPT_IMPLICIT)
-                || (prog->reganch & ROPT_ANCH_MBOL)) /* XXXX SBOL? */
+       else if (multiline || (prog->intflags & PREGf_IMPLICIT)
+                || (prog->extflags & RXf_ANCH_MBOL)) /* XXXX SBOL? */
        {
            char *end;
 
@@ -1726,13 +2016,13 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                if (s == startpos)
                    goto after_try;
                while (1) {
-                   if (regtry(&reginfo, s))
+                   if (regtry(&reginfo, &s))
                        goto got_it;
                  after_try:
-                   if (s >= end)
+                   if (s > end)
                        goto phooey;
-                   if (prog->reganch & RE_USE_INTUIT) {
-                       s = re_intuit_start(prog, sv, s + 1, strend, flags, NULL);
+                   if (prog->extflags & RXf_USE_INTUIT) {
+                       s = re_intuit_start(rx, sv, s + 1, strend, flags, NULL);
                        if (!s)
                            goto phooey;
                    }
@@ -1744,54 +2034,58 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                    s--;
                while (s < end) {
                    if (*s++ == '\n') { /* don't need PL_utf8skip here */
-                       if (regtry(&reginfo, s))
+                       if (regtry(&reginfo, &s))
                            goto got_it;
                    }
                }               
            }
        }
        goto phooey;
-    } else if (prog->reganch & ROPT_ANCH_GPOS) {
-       if (regtry(&reginfo, reginfo.ganch))
+    } else if (RXf_GPOS_CHECK == (prog->extflags & RXf_GPOS_CHECK)) 
+    {
+        /* the warning about reginfo.ganch being used without intialization
+           is bogus -- we set it above, when prog->extflags & RXf_GPOS_SEEN 
+           and we only enter this block when the same bit is set. */
+        char *tmp_s = reginfo.ganch - prog->gofs;
+
+       if (tmp_s >= strbeg && regtry(&reginfo, &tmp_s))
            goto got_it;
        goto phooey;
     }
 
     /* Messy cases:  unanchored match. */
-    if ((prog->anchored_substr || prog->anchored_utf8) && prog->reganch & ROPT_SKIP) {
+    if ((prog->anchored_substr || prog->anchored_utf8) && prog->intflags & PREGf_SKIP) {
        /* we have /x+whatever/ */
-       /* it must be a one character string (XXXX Except UTF?) */
+       /* it must be a one character string (XXXX Except UTF_PATTERN?) */
        char ch;
 #ifdef DEBUGGING
        int did_match = 0;
 #endif
-       if (!(do_utf8 ? prog->anchored_utf8 : prog->anchored_substr))
-           do_utf8 ? to_utf8_substr(prog) : to_byte_substr(prog);
-       ch = SvPVX_const(do_utf8 ? prog->anchored_utf8 : prog->anchored_substr)[0];
+       if (!(utf8_target ? prog->anchored_utf8 : prog->anchored_substr))
+           utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
+       ch = SvPVX_const(utf8_target ? prog->anchored_utf8 : prog->anchored_substr)[0];
 
-       if (do_utf8) {
-           while (s < strend) {
+       if (utf8_target) {
+           REXEC_FBC_SCAN(
                if (*s == ch) {
                    DEBUG_EXECUTE_r( did_match = 1 );
-                   if (regtry(&reginfo, s)) goto got_it;
+                   if (regtry(&reginfo, &s)) goto got_it;
                    s += UTF8SKIP(s);
                    while (s < strend && *s == ch)
                        s += UTF8SKIP(s);
                }
-               s += UTF8SKIP(s);
-           }
+           );
        }
        else {
-           while (s < strend) {
+           REXEC_FBC_SCAN(
                if (*s == ch) {
                    DEBUG_EXECUTE_r( did_match = 1 );
-                   if (regtry(&reginfo, s)) goto got_it;
+                   if (regtry(&reginfo, &s)) goto got_it;
                    s++;
                    while (s < strend && *s == ch)
                        s++;
                }
-               s++;
-           }
+           );
        }
        DEBUG_EXECUTE_r(if (!did_match)
                PerlIO_printf(Perl_debug_log,
@@ -1811,25 +2105,30 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        int did_match = 0;
 #endif
        if (prog->anchored_substr || prog->anchored_utf8) {
-           if (!(do_utf8 ? prog->anchored_utf8 : prog->anchored_substr))
-               do_utf8 ? to_utf8_substr(prog) : to_byte_substr(prog);
-           must = do_utf8 ? prog->anchored_utf8 : prog->anchored_substr;
+           if (!(utf8_target ? prog->anchored_utf8 : prog->anchored_substr))
+               utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
+           must = utf8_target ? prog->anchored_utf8 : prog->anchored_substr;
            back_max = back_min = prog->anchored_offset;
        } else {
-           if (!(do_utf8 ? prog->float_utf8 : prog->float_substr))
-               do_utf8 ? to_utf8_substr(prog) : to_byte_substr(prog);
-           must = do_utf8 ? prog->float_utf8 : prog->float_substr;
+           if (!(utf8_target ? prog->float_utf8 : prog->float_substr))
+               utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
+           must = utf8_target ? prog->float_utf8 : prog->float_substr;
            back_max = prog->float_max_offset;
            back_min = prog->float_min_offset;
        }
+       
+           
        if (must == &PL_sv_undef)
            /* could not downgrade utf8 check substring, so must fail */
            goto phooey;
 
-       last = HOP3c(strend,    /* Cannot start after this */
-                         -(I32)(CHR_SVLEN(must)
-                                - (SvTAIL(must) != 0) + back_min), strbeg);
-
+        if (back_min<0) {
+           last = strend;
+       } else {
+            last = HOP3c(strend,       /* Cannot start after this */
+                 -(I32)(CHR_SVLEN(must)
+                        - (SvTAIL(must) != 0) + back_min), strbeg);
+        }
        if (s > PL_bostr)
            last1 = HOPc(s, -1);
        else
@@ -1842,13 +2141,13 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        strend = HOPc(strend, -dontbother);
        while ( (s <= last) &&
                ((flags & REXEC_SCREAM)
-                ? (s = screaminstr(sv, must, HOP3c(s, back_min, strend) - strbeg,
+                ? (s = screaminstr(sv, must, HOP3c(s, back_min, (back_min<0 ? strbeg : strend)) - strbeg,
                                    end_shift, &scream_pos, 0))
-                : (s = fbm_instr((unsigned char*)HOP3(s, back_min, strend),
+                : (s = fbm_instr((unsigned char*)HOP3(s, back_min, (back_min<0 ? strbeg : strend)),
                                  (unsigned char*)strend, must,
                                  multiline ? FBMrf_MULTILINE : 0))) ) {
            /* we may be pointing at the wrong string */
-           if ((flags & REXEC_SCREAM) && RX_MATCH_COPIED(prog))
+           if ((flags & REXEC_SCREAM) && RXp_MATCH_COPIED(prog))
                s = strbeg + (s - SvPVX_const(sv));
            DEBUG_EXECUTE_r( did_match = 1 );
            if (HOPc(s, -back_max) > last1) {
@@ -1861,64 +2160,53 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                last1 = HOPc(s, -back_min);
                s = t;
            }
-           if (do_utf8) {
+           if (utf8_target) {
                while (s <= last1) {
-                   if (regtry(&reginfo, s))
+                   if (regtry(&reginfo, &s))
                        goto got_it;
                    s += UTF8SKIP(s);
                }
            }
            else {
                while (s <= last1) {
-                   if (regtry(&reginfo, s))
+                   if (regtry(&reginfo, &s))
                        goto got_it;
                    s++;
                }
            }
        }
-       DEBUG_EXECUTE_r(if (!did_match)
-                    PerlIO_printf(Perl_debug_log, 
-                                  "Did not find %s substr \"%s%.*s%s\"%s...\n",
+       DEBUG_EXECUTE_r(if (!did_match) {
+            RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
+                SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
+            PerlIO_printf(Perl_debug_log, "Did not find %s substr %s%s...\n",
                              ((must == prog->anchored_substr || must == prog->anchored_utf8)
                               ? "anchored" : "floating"),
-                             PL_colors[0],
-                             (int)(SvCUR(must) - (SvTAIL(must)!=0)),
-                             SvPVX_const(must),
-                                  PL_colors[1], (SvTAIL(must) ? "$" : ""))
-               );
+                quoted, RE_SV_TAIL(must));
+        });                
        goto phooey;
     }
-    else if ((c = prog->regstclass)) {
+    else if ( (c = progi->regstclass) ) {
        if (minlen) {
-           I32 op = (U8)OP(prog->regstclass);
+           const OPCODE op = OP(progi->regstclass);
            /* don't bother with what can't match */
-           if (PL_regkind[op] != EXACT && op != CANY)
+           if (PL_regkind[op] != EXACT && op != CANY && PL_regkind[op] != TRIE)
                strend = HOPc(strend, -(minlen - 1));
        }
        DEBUG_EXECUTE_r({
-           SV *prop = sv_newmortal();
-           const char *s0;
-           const char *s1;
-           int len0;
-           int len1;
-
+           SV * const prop = sv_newmortal();
            regprop(prog, prop, c);
-           s0 = UTF ?
-             pv_uni_display(dsv0, (U8*)SvPVX_const(prop), SvCUR(prop), 60,
-                            UNI_DISPLAY_REGEX) :
-             SvPVX_const(prop);
-           len0 = UTF ? SvCUR(dsv0) : SvCUR(prop);
-           s1 = UTF ?
-             sv_uni_display(dsv1, sv, 60, UNI_DISPLAY_REGEX) : s;
-           len1 = UTF ? SvCUR(dsv1) : strend - s;
-           PerlIO_printf(Perl_debug_log,
-                         "Matching stclass \"%*.*s\" against \"%*.*s\"\n",
-                         len0, len0, s0,
-                         len1, len1, s1);
+           {
+               RE_PV_QUOTED_DECL(quoted,utf8_target,PERL_DEBUG_PAD_ZERO(1),
+                   s,strend-s,60);
+               PerlIO_printf(Perl_debug_log,
+                   "Matching stclass %.*s against %s (%d bytes)\n",
+                   (int)SvCUR(prop), SvPVX_const(prop),
+                    quoted, (int)(strend - s));
+           }
        });
         if (find_byclass(prog, c, s, strend, &reginfo))
            goto got_it;
-       DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Contradicts stclass...\n"));
+       DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Contradicts stclass... [regexec_flags]\n"));
     }
     else {
        dontbother = 0;
@@ -1927,9 +2215,9 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
            char *last;
            SV* float_real;
 
-           if (!(do_utf8 ? prog->float_utf8 : prog->float_substr))
-               do_utf8 ? to_utf8_substr(prog) : to_byte_substr(prog);
-           float_real = do_utf8 ? prog->float_utf8 : prog->float_substr;
+           if (!(utf8_target ? prog->float_utf8 : prog->float_substr))
+               utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
+           float_real = utf8_target ? prog->float_utf8 : prog->float_substr;
 
            if (flags & REXEC_SCREAM) {
                last = screaminstr(sv, float_real, s - strbeg,
@@ -1937,7 +2225,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                if (!last)
                    last = scream_olds; /* Only one occurrence. */
                /* we may be pointing at the wrong string */
-               else if (RX_MATCH_COPIED(prog))
+               else if (RXp_MATCH_COPIED(prog))
                    s = strbeg + (s - SvPVX_const(sv));
            }
            else {
@@ -1961,9 +2249,10 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                }
            }
            if (last == NULL) {
-               DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
-                                     "%sCan't trim the tail, match fails (should not happen)%s\n",
-                                     PL_colors[4], PL_colors[5]));
+               DEBUG_EXECUTE_r(
+                   PerlIO_printf(Perl_debug_log,
+                       "%sCan't trim the tail, match fails (should not happen)%s\n",
+                       PL_colors[4], PL_colors[5]));
                goto phooey; /* Should not happen! */
            }
            dontbother = strend - last + prog->float_min_offset;
@@ -1972,9 +2261,9 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
            dontbother = minlen - 1;
        strend -= dontbother;              /* this one's always in bytes! */
        /* We don't know much -- general case. */
-       if (do_utf8) {
+       if (utf8_target) {
            for (;;) {
-               if (regtry(&reginfo, s))
+               if (regtry(&reginfo, &s))
                    goto got_it;
                if (s >= strend)
                    break;
@@ -1983,7 +2272,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        }
        else {
            do {
-               if (regtry(&reginfo, s))
+               if (regtry(&reginfo, &s))
                    goto got_it;
            } while (s++ < strend);
        }
@@ -1993,22 +2282,19 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     goto phooey;
 
 got_it:
-    RX_MATCH_TAINTED_set(prog, PL_reg_flags & RF_tainted);
+    Safefree(swap);
+    RX_MATCH_TAINTED_set(rx, PL_reg_flags & RF_tainted);
 
-    if (PL_reg_eval_set) {
-       /* Preserve the current value of $^R */
-       if (oreplsv != GvSV(PL_replgv))
-           sv_setsv(oreplsv, GvSV(PL_replgv));/* So that when GvSV(replgv) is
-                                                 restored, the value remains
-                                                 the same. */
+    if (PL_reg_eval_set)
        restore_pos(aTHX_ prog);
-    }
+    if (RXp_PAREN_NAMES(prog)) 
+        (void)hv_iterinit(RXp_PAREN_NAMES(prog));
 
     /* make sure $`, $&, $', and $digit will work later */
     if ( !(flags & REXEC_NOT_FIRST) ) {
-       RX_MATCH_COPY_FREE(prog);
+       RX_MATCH_COPY_FREE(rx);
        if (flags & REXEC_COPY_STR) {
-           I32 i = PL_regeol - startpos + (stringarg - strbeg);
+           const I32 i = PL_regeol - startpos + (stringarg - strbeg);
 #ifdef PERL_OLD_COPY_ON_WRITE
            if ((SvIsCOW(sv)
                 || (SvFLAGS(sv) & CAN_COW_MASK) == CAN_COW_FLAGS)) {
@@ -2023,7 +2309,7 @@ got_it:
            } else
 #endif
            {
-               RX_MATCH_COPIED_on(prog);
+               RX_MATCH_COPIED_on(rx);
                s = savepvn(strbeg, i);
                prog->subbeg = s;
            }
@@ -2042,26 +2328,34 @@ phooey:
                          PL_colors[4], PL_colors[5]));
     if (PL_reg_eval_set)
        restore_pos(aTHX_ prog);
+    if (swap) {
+        /* we failed :-( roll it back */
+        Safefree(prog->offs);
+        prog->offs = swap;
+    }
+
     return 0;
 }
 
+
 /*
  - regtry - try match at specific point
  */
 STATIC I32                     /* 0 failure, 1 success */
-S_regtry(pTHX_ const regmatch_info *reginfo, char *startpos)
+S_regtry(pTHX_ regmatch_info *reginfo, char **startpos)
 {
     dVAR;
-    register I32 *sp;
-    register I32 *ep;
     CHECKPOINT lastcp;
-    regexp *prog = reginfo->prog;
+    REGEXP *const rx = reginfo->prog;
+    regexp *const prog = (struct regexp *)SvANY(rx);
+    RXi_GET_DECL(prog,progi);
     GET_RE_DEBUG_FLAGS_DECL;
 
-#ifdef DEBUGGING
-    PL_regindent = 0;  /* XXXX Not good when matches are reenterable... */
-#endif
-    if ((prog->reganch & ROPT_EVAL_SEEN) && !PL_reg_eval_set) {
+    PERL_ARGS_ASSERT_REGTRY;
+
+    reginfo->cutpoint=NULL;
+
+    if ((prog->extflags & RXf_EVAL_SEEN) && !PL_reg_eval_set) {
        MAGIC *mg;
 
        PL_reg_eval_set = RS_init;
@@ -2069,7 +2363,7 @@ S_regtry(pTHX_ const regmatch_info *reginfo, char *startpos)
            PerlIO_printf(Perl_debug_log, "  setting stack tmpbase at %"IVdf"\n",
                          (IV)(PL_stack_sp - PL_stack_base));
            ));
-       SAVEI32(cxstack[cxstack_ix].blk_oldsp);
+       SAVESTACK_CXPOS();
        cxstack[cxstack_ix].blk_oldsp = PL_stack_sp - PL_stack_base;
        /* Otherwise OP_NEXTSTATE will free whatever on stack now.  */
        SAVETMPS;
@@ -2081,17 +2375,17 @@ S_regtry(pTHX_ const regmatch_info *reginfo, char *startpos)
            /* Make $_ available to executed code. */
            if (reginfo->sv != DEFSV) {
                SAVE_DEFSV;
-               DEFSV = reginfo->sv;
+               DEFSV_set(reginfo->sv);
            }
        
            if (!(SvTYPE(reginfo->sv) >= SVt_PVMG && SvMAGIC(reginfo->sv)
                  && (mg = mg_find(reginfo->sv, PERL_MAGIC_regex_global)))) {
                /* prepare for quick setting of pos */
 #ifdef PERL_OLD_COPY_ON_WRITE
-               if (SvIsCOW(sv))
-                   sv_force_normal_flags(sv, 0);
+               if (SvIsCOW(reginfo->sv))
+                   sv_force_normal_flags(reginfo->sv, 0);
 #endif
-               mg = sv_magicext(reginfo->sv, (SV*)0, PERL_MAGIC_regex_global,
+               mg = sv_magicext(reginfo->sv, NULL, PERL_MAGIC_regex_global,
                                 &PL_vtbl_mglob, NULL, 0);
                mg->mg_len = -1;
            }
@@ -2103,19 +2397,28 @@ S_regtry(pTHX_ const regmatch_info *reginfo, char *startpos)
            Newxz(PL_reg_curpm, 1, PMOP);
 #ifdef USE_ITHREADS
             {
-                SV* repointer = newSViv(0);
-                /* so we know which PL_regex_padav element is PL_reg_curpm */
-                SvFLAGS(repointer) |= SVf_BREAK;
-                av_push(PL_regex_padav,repointer);
+               SV* const repointer = &PL_sv_undef;
+                /* this regexp is also owned by the new PL_reg_curpm, which
+                  will try to free it.  */
+                av_push(PL_regex_padav, repointer);
                 PL_reg_curpm->op_pmoffset = av_len(PL_regex_padav);
                 PL_regex_pad = AvARRAY(PL_regex_padav);
             }
 #endif      
         }
-       PM_SETRE(PL_reg_curpm, prog);
+#ifdef USE_ITHREADS
+       /* It seems that non-ithreads works both with and without this code.
+          So for efficiency reasons it seems best not to have the code
+          compiled when it is not needed.  */
+       /* This is safe against NULLs: */
+       ReREFCNT_dec(PM_GETRE(PL_reg_curpm));
+       /* PM_reg_curpm owns a reference to this regexp.  */
+       ReREFCNT_inc(rx);
+#endif
+       PM_SETRE(PL_reg_curpm, rx);
        PL_reg_oldcurpm = PL_curpm;
        PL_curpm = PL_reg_curpm;
-       if (RX_MATCH_COPIED(prog)) {
+       if (RXp_MATCH_COPIED(prog)) {
            /*  Here is a serious problem: we cannot rewrite subbeg,
                since it may be needed if this match fails.  Thus
                $` inside (?{}) could fail... */
@@ -2124,23 +2427,22 @@ S_regtry(pTHX_ const regmatch_info *reginfo, char *startpos)
 #ifdef PERL_OLD_COPY_ON_WRITE
            PL_nrs = prog->saved_copy;
 #endif
-           RX_MATCH_COPIED_off(prog);
+           RXp_MATCH_COPIED_off(prog);
        }
        else
            PL_reg_oldsaved = NULL;
        prog->subbeg = PL_bostr;
        prog->sublen = PL_regeol - PL_bostr; /* strend may have been modified */
     }
-    prog->startp[0] = startpos - PL_bostr;
-    PL_reginput = startpos;
-    PL_regstartp = prog->startp;
-    PL_regendp = prog->endp;
+    DEBUG_EXECUTE_r(PL_reg_starttry = *startpos);
+    prog->offs[0].start = *startpos - PL_bostr;
+    PL_reginput = *startpos;
     PL_reglastparen = &prog->lastparen;
     PL_reglastcloseparen = &prog->lastcloseparen;
     prog->lastparen = 0;
     prog->lastcloseparen = 0;
     PL_regsize = 0;
-    DEBUG_EXECUTE_r(PL_reg_starttry = startpos);
+    PL_regoffs = prog->offs;
     if (PL_reg_start_tmpl <= prog->nparens) {
        PL_reg_start_tmpl = prog->nparens*3/2 + 3;
         if(PL_reg_start_tmp)
@@ -2156,134 +2458,55 @@ S_regtry(pTHX_ const regmatch_info *reginfo, char *startpos)
     /* Tests pat.t#187 and split.t#{13,14} seem to depend on this code.
      * Actually, the code in regcppop() (which Ilya may be meaning by
      * PL_reglastparen), is not needed at all by the test suite
-     * (op/regexp, op/pat, op/split), but that code is needed, oddly
-     * enough, for building DynaLoader, or otherwise this
-     * "Error: '*' not in typemap in DynaLoader.xs, line 164"
-     * will happen.  Meanwhile, this code *is* needed for the
+     * (op/regexp, op/pat, op/split), but that code is needed otherwise
+     * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
+     * Meanwhile, this code *is* needed for the
      * above-mentioned test suite tests to succeed.  The common theme
      * on those tests seems to be returning null fields from matches.
-     * --jhi */
+     * --jhi updated by dapm */
 #if 1
-    sp = prog->startp;
-    ep = prog->endp;
     if (prog->nparens) {
+       regexp_paren_pair *pp = PL_regoffs;
        register I32 i;
        for (i = prog->nparens; i > (I32)*PL_reglastparen; i--) {
-           *++sp = -1;
-           *++ep = -1;
+           ++pp;
+           pp->start = -1;
+           pp->end = -1;
        }
     }
 #endif
     REGCP_SET(lastcp);
-    if (regmatch(reginfo, prog->program + 1)) {
-       prog->endp[0] = PL_reginput - PL_bostr;
+    if (regmatch(reginfo, progi->program + 1)) {
+       PL_regoffs[0].end = PL_reginput - PL_bostr;
        return 1;
     }
+    if (reginfo->cutpoint)
+        *startpos= reginfo->cutpoint;
     REGCP_UNWIND(lastcp);
     return 0;
 }
 
-#define RE_UNWIND_BRANCH       1
-#define RE_UNWIND_BRANCHJ      2
-
-union re_unwind_t;
-
-typedef struct {               /* XX: makes sense to enlarge it... */
-    I32 type;
-    I32 prev;
-    CHECKPOINT lastcp;
-} re_unwind_generic_t;
-
-typedef struct {
-    I32 type;
-    I32 prev;
-    CHECKPOINT lastcp;
-    I32 lastparen;
-    regnode *next;
-    char *locinput;
-    I32 nextchr;
-    int minmod;
-#ifdef DEBUGGING
-    int regindent;
-#endif
-} re_unwind_branch_t;
-
-typedef union re_unwind_t {
-    I32 type;
-    re_unwind_generic_t generic;
-    re_unwind_branch_t branch;
-} re_unwind_t;
 
 #define sayYES goto yes
 #define sayNO goto no
-#define sayNO_ANYOF goto no_anyof
-#define sayYES_FINAL goto yes_final
-#define sayNO_FINAL  goto no_final
-#define sayNO_SILENT goto do_no
-#define saySAME(x) if (x) goto yes; else goto no
-
-#define POSCACHE_SUCCESS 0     /* caching success rather than failure */
-#define POSCACHE_SEEN 1                /* we know what we're caching */
-#define POSCACHE_START 2       /* the real cache: this bit maps to pos 0 */
-
-#define CACHEsayYES STMT_START { \
-    if (st->u.whilem.cache_offset | st->u.whilem.cache_bit) { \
-       if (!(PL_reg_poscache[0] & (1<<POSCACHE_SEEN))) { \
-           PL_reg_poscache[0] |= (1<<POSCACHE_SUCCESS) | (1<<POSCACHE_SEEN); \
-           PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
-       } \
-        else if (PL_reg_poscache[0] & (1<<POSCACHE_SUCCESS)) { \
-           PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
-       } \
-       else { \
-           /* cache records failure, but this is success */ \
-           DEBUG_r( \
-               PerlIO_printf(Perl_debug_log, \
-                   "%*s  (remove success from failure cache)\n", \
-                   REPORT_CODE_OFF+PL_regindent*2, "") \
-           ); \
-           PL_reg_poscache[st->u.whilem.cache_offset] &= ~(1<<st->u.whilem.cache_bit); \
-       } \
-    } \
-    sayYES; \
-} STMT_END
+#define sayNO_SILENT goto no_silent
 
-#define CACHEsayNO STMT_START { \
-    if (st->u.whilem.cache_offset | st->u.whilem.cache_bit) { \
-       if (!(PL_reg_poscache[0] & (1<<POSCACHE_SEEN))) { \
-           PL_reg_poscache[0] |= (1<<POSCACHE_SEEN); \
-           PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
-       } \
-        else if (!(PL_reg_poscache[0] & (1<<POSCACHE_SUCCESS))) { \
-           PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
-       } \
-       else { \
-           /* cache records success, but this is failure */ \
-           DEBUG_r( \
-               PerlIO_printf(Perl_debug_log, \
-                   "%*s  (remove failure from success cache)\n", \
-                   REPORT_CODE_OFF+PL_regindent*2, "") \
-           ); \
-           PL_reg_poscache[st->u.whilem.cache_offset] &= ~(1<<st->u.whilem.cache_bit); \
-       } \
-    } \
-    sayNO; \
-} STMT_END
+/* we dont use STMT_START/END here because it leads to 
+   "unreachable code" warnings, which are bogus, but distracting. */
+#define CACHEsayNO \
+    if (ST.cache_mask) \
+       PL_reg_poscache[ST.cache_offset] |= ST.cache_mask; \
+    sayNO
 
 /* this is used to determine how far from the left messages like
-   'failed...' are printed. Currently 29 makes these messages line
-   up with the opcode they refer to. Earlier perls used 25 which
-   left these messages outdented making reviewing a debug output
-   quite difficult.
+   'failed...' are printed. It should be set such that messages 
+   are inline with the regop output that created them.
 */
-#define REPORT_CODE_OFF 29
+#define REPORT_CODE_OFF 32
 
 
-/* Make sure there is a test for this +1 options in re_tests */
-#define TRIE_INITAL_ACCEPT_BUFFLEN 4;
-
-/* this value indiciates that the c1/c2 "next char" test should be skipped */
-#define CHRTEST_VOID -1000
+#define CHRTEST_UNINIT -1001 /* c1/c2 haven't been calculated yet */
+#define CHRTEST_VOID   -1000 /* the c1/c2 "next char" test should be skipped */
 
 #define SLAB_FIRST(s) (&(s)->states[0])
 #define SLAB_LAST(s)  (&(s)->states[PERL_REGMATCH_SLAB_SLOTS-1])
@@ -2293,7 +2516,7 @@ typedef union re_unwind_t {
 STATIC regmatch_state *
 S_push_slab(pTHX)
 {
-#if PERL_VERSION < 9
+#if PERL_VERSION < 9 && !defined(PERL_CORE)
     dMY_CXT;
 #endif
     regmatch_slab *s = PL_regmatch_slab->next;
@@ -2307,198 +2530,392 @@ S_push_slab(pTHX)
     return SLAB_FIRST(s);
 }
 
-/* simulate a recursive call to regmatch */
-
-#define REGMATCH(ns, where) \
-    st->scan = scan; \
-    scan = (ns); \
-    st->resume_state = resume_##where; \
-    goto start_recurse; \
-    resume_point_##where:
-
-
-/* push a new regex state. Set newst to point to it */
-
-#define PUSH_STATE(newst, resume) \
-    depth++;   \
-    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "PUSH STATE(%d)\n", depth)); \
-    st->scan = scan;   \
-    st->next = next;   \
-    st->n = n; \
-    st->locinput = locinput;   \
-    st->resume_state = resume; \
-    newst = st+1;   \
-    if (newst >  SLAB_LAST(PL_regmatch_slab)) \
-       newst = S_push_slab(aTHX);  \
-    PL_regmatch_state = newst; \
-    newst->cc = 0;  \
-    newst->minmod = 0; \
-    newst->sw = 0;  \
-    newst->logical = 0;        \
-    newst->unwind = 0; \
-    locinput = PL_reginput; \
-    nextchr = UCHARAT(locinput);    
-
-#define POP_STATE \
-    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "POP STATE(%d)\n", depth)); \
-    depth--; \
-    st--; \
-    if (st < SLAB_FIRST(PL_regmatch_slab)) { \
-       PL_regmatch_slab = PL_regmatch_slab->prev; \
-       st = SLAB_LAST(PL_regmatch_slab); \
-    } \
-    PL_regmatch_state = st; \
-    scan       = st->scan; \
-    next       = st->next; \
-    n          = st->n; \
-    locinput   = st->locinput; \
-    nextchr = UCHARAT(locinput);
+
+/* push a new state then goto it */
+
+#define PUSH_STATE_GOTO(state, node) \
+    scan = node; \
+    st->resume_state = state; \
+    goto push_state;
+
+/* push a new state with success backtracking, then goto it */
+
+#define PUSH_YES_STATE_GOTO(state, node) \
+    scan = node; \
+    st->resume_state = state; \
+    goto push_yes_state;
+
+
 
 /*
- - regmatch - main matching routine
- *
- * Conceptually the strategy is simple:  check to see whether the current
- * node matches, call self recursively to see whether the rest matches,
- * and then act accordingly.  In practice we make some effort to avoid
- * recursion, in particular by going through "ordinary" nodes (that don't
- * need to know whether the rest of the match failed) by a loop instead of
- * by recursion.
- */
-/* [lwall] I've hoisted the register declarations to the outer block in order to
- * maybe save a little bit of pushing and popping on the stack.  It also takes
- * advantage of machines that use a register save mask on subroutine entry.
- *
- * This function used to be heavily recursive, but since this had the
- * effect of blowing the CPU stack on complex regexes, it has been
- * restructured to be iterative, and to save state onto the heap rather
- * than the stack. Essentially whereever regmatch() used to be called, it
- * pushes the current state, notes where to return, then jumps back into
- * the main loop.
- *
- * Originally the structure of this function used to look something like
 
-    S_regmatch() {
-       int a = 1, b = 2;
+regmatch() - main matching routine
+
+This is basically one big switch statement in a loop. We execute an op,
+set 'next' to point the next op, and continue. If we come to a point which
+we may need to backtrack to on failure such as (A|B|C), we push a
+backtrack state onto the backtrack stack. On failure, we pop the top
+state, and re-enter the loop at the state indicated. If there are no more
+states to pop, we return failure.
+
+Sometimes we also need to backtrack on success; for example /A+/, where
+after successfully matching one A, we need to go back and try to
+match another one; similarly for lookahead assertions: if the assertion
+completes successfully, we backtrack to the state just before the assertion
+and then carry on.  In these cases, the pushed state is marked as
+'backtrack on success too'. This marking is in fact done by a chain of
+pointers, each pointing to the previous 'yes' state. On success, we pop to
+the nearest yes state, discarding any intermediate failure-only states.
+Sometimes a yes state is pushed just to force some cleanup code to be
+called at the end of a successful match or submatch; e.g. (??{$re}) uses
+it to free the inner regex.
+
+Note that failure backtracking rewinds the cursor position, while
+success backtracking leaves it alone.
+
+A pattern is complete when the END op is executed, while a subpattern
+such as (?=foo) is complete when the SUCCESS op is executed. Both of these
+ops trigger the "pop to last yes state if any, otherwise return true"
+behaviour.
+
+A common convention in this function is to use A and B to refer to the two
+subpatterns (or to the first nodes thereof) in patterns like /A*B/: so A is
+the subpattern to be matched possibly multiple times, while B is the entire
+rest of the pattern. Variable and state names reflect this convention.
+
+The states in the main switch are the union of ops and failure/success of
+substates associated with with that op.  For example, IFMATCH is the op
+that does lookahead assertions /(?=A)B/ and so the IFMATCH state means
+'execute IFMATCH'; while IFMATCH_A is a state saying that we have just
+successfully matched A and IFMATCH_A_fail is a state saying that we have
+just failed to match A. Resume states always come in pairs. The backtrack
+state we push is marked as 'IFMATCH_A', but when that is popped, we resume
+at IFMATCH_A or IFMATCH_A_fail, depending on whether we are backtracking
+on success or failure.
+
+The struct that holds a backtracking state is actually a big union, with
+one variant for each major type of op. The variable st points to the
+top-most backtrack struct. To make the code clearer, within each
+block of code we #define ST to alias the relevant union.
+
+Here's a concrete example of a (vastly oversimplified) IFMATCH
+implementation:
+
+    switch (state) {
+    ....
+
+#define ST st->u.ifmatch
+
+    case IFMATCH: // we are executing the IFMATCH op, (?=A)B
+       ST.foo = ...; // some state we wish to save
        ...
-       while (scan != NULL) {
-           a++; // do stuff with a and b
-           ...
-           switch (OP(scan)) {
-               case FOO: {
-                   int local = 3;
-                   ...
-                   if (regmatch(...))  // recurse
-                       goto yes;
-               }
-               ...
-           }
-       }
-       yes:
-       return 1;
-    }
+       // push a yes backtrack state with a resume value of
+       // IFMATCH_A/IFMATCH_A_fail, then continue execution at the
+       // first node of A:
+       PUSH_YES_STATE_GOTO(IFMATCH_A, A);
+       // NOTREACHED
+
+    case IFMATCH_A: // we have successfully executed A; now continue with B
+       next = B;
+       bar = ST.foo; // do something with the preserved value
+       break;
+
+    case IFMATCH_A_fail: // A failed, so the assertion failed
+       ...;   // do some housekeeping, then ...
+       sayNO; // propagate the failure
 
- * Now it looks something like this:
+#undef ST
+
+    ...
+    }
 
-    typedef struct {
-       int a, b, local;
-       int resume_state;
-    } regmatch_state;
+For any old-timers reading this who are familiar with the old recursive
+approach, the code above is equivalent to:
 
-    S_regmatch() {
-       regmatch_state *st = new();
-       int depth=0;
-       st->a++; // do stuff with a and b
+    case IFMATCH: // we are executing the IFMATCH op, (?=A)B
+    {
+       int foo = ...
        ...
-       while (scan != NULL) {
-           ...
-           switch (OP(scan)) {
-               case FOO: {
-                   st->local = 3;
-                   ...
-                   st->scan = scan;
-                   scan = ...;
-                   st->resume_state = resume_FOO;
-                   goto start_recurse; // recurse
-
-                   resume_point_FOO:
-                   if (result)
-                       goto yes;
-               }
-               ...
-           }
-         start_recurse:
-           st = new(); push a new state
-           st->a = 1; st->b = 2;
-           depth++;
-       }
-      yes:
-       result = 1;
-       if (depth--) {
-           st = pop();
-           switch (resume_state) {
-           case resume_FOO:
-               goto resume_point_FOO;
-           ...
-           }
+       if (regmatch(A)) {
+           next = B;
+           bar = foo;
+           break;
        }
-       return result
+       ...;   // do some housekeeping, then ...
+       sayNO; // propagate the failure
     }
-           
- * WARNING: this means that any line in this function that contains a
- * REGMATCH() or TRYPAREN() is actually simulating a recursive call to
- * regmatch() using gotos instead. Thus the values of any local variables
- * not saved in the regmatch_state structure will have been lost when
- * execution resumes on the next line .
- *
- * States (ie the st pointer) are allocated in slabs of about 4K in size.
- * PL_regmatch_state always points to the currently active state, and
- * PL_regmatch_slab points to the slab currently containing PL_regmatch_state.
- * The first time regmatch is called, the first slab is allocated, and is
- * never freed until interpreter desctruction. When the slab is full,
- * a new one is allocated chained to the end. At exit from regmatch, slabs
- * allocated since entry are freed.
- */
+
+The topmost backtrack state, pointed to by st, is usually free. If you
+want to claim it, populate any ST.foo fields in it with values you wish to
+save, then do one of
+
+       PUSH_STATE_GOTO(resume_state, node);
+       PUSH_YES_STATE_GOTO(resume_state, node);
+
+which sets that backtrack state's resume value to 'resume_state', pushes a
+new free entry to the top of the backtrack stack, then goes to 'node'.
+On backtracking, the free slot is popped, and the saved state becomes the
+new free state. An ST.foo field in this new top state can be temporarily
+accessed to retrieve values, but once the main loop is re-entered, it
+becomes available for reuse.
+
+Note that the depth of the backtrack stack constantly increases during the
+left-to-right execution of the pattern, rather than going up and down with
+the pattern nesting. For example the stack is at its maximum at Z at the
+end of the pattern, rather than at X in the following:
+
+    /(((X)+)+)+....(Y)+....Z/
+
+The only exceptions to this are lookahead/behind assertions and the cut,
+(?>A), which pop all the backtrack states associated with A before
+continuing.
+Bascktrack state structs are allocated in slabs of about 4K in size.
+PL_regmatch_state and st always point to the currently active state,
+and PL_regmatch_slab points to the slab currently containing
+PL_regmatch_state.  The first time regmatch() is called, the first slab is
+allocated, and is never freed until interpreter destruction. When the slab
+is full, a new one is allocated and chained to the end. At exit from
+regmatch(), slabs allocated since entry are freed.
+
+*/
  
 
+#define DEBUG_STATE_pp(pp)                                 \
+    DEBUG_STATE_r({                                        \
+       DUMP_EXEC_POS(locinput, scan, utf8_target);                 \
+       PerlIO_printf(Perl_debug_log,                       \
+           "    %*s"pp" %s%s%s%s%s\n",                     \
+           depth*2, "",                                    \
+           PL_reg_name[st->resume_state],                     \
+           ((st==yes_state||st==mark_state) ? "[" : ""),   \
+           ((st==yes_state) ? "Y" : ""),                   \
+           ((st==mark_state) ? "M" : ""),                  \
+           ((st==yes_state||st==mark_state) ? "]" : "")    \
+       );                                                  \
+    });
+
+
+#define REG_NODE_NUM(x) ((x) ? (int)((x)-prog) : -1)
+
+#ifdef DEBUGGING
+
+STATIC void
+S_debug_start_match(pTHX_ const REGEXP *prog, const bool utf8_target,
+    const char *start, const char *end, const char *blurb)
+{
+    const bool utf8_pat = RX_UTF8(prog) ? 1 : 0;
+
+    PERL_ARGS_ASSERT_DEBUG_START_MATCH;
+
+    if (!PL_colorset)   
+            reginitcolors();    
+    {
+        RE_PV_QUOTED_DECL(s0, utf8_pat, PERL_DEBUG_PAD_ZERO(0), 
+            RX_PRECOMP_const(prog), RX_PRELEN(prog), 60);   
+        
+        RE_PV_QUOTED_DECL(s1, utf8_target, PERL_DEBUG_PAD_ZERO(1),
+            start, end - start, 60); 
+        
+        PerlIO_printf(Perl_debug_log, 
+            "%s%s REx%s %s against %s\n", 
+                      PL_colors[4], blurb, PL_colors[5], s0, s1); 
+        
+        if (utf8_target||utf8_pat)
+            PerlIO_printf(Perl_debug_log, "UTF-8 %s%s%s...\n",
+                utf8_pat ? "pattern" : "",
+                utf8_pat && utf8_target ? " and " : "",
+                utf8_target ? "string" : ""
+            ); 
+    }
+}
+
+STATIC void
+S_dump_exec_pos(pTHX_ const char *locinput, 
+                      const regnode *scan, 
+                      const char *loc_regeol, 
+                      const char *loc_bostr, 
+                      const char *loc_reg_starttry,
+                      const bool utf8_target)
+{
+    const int docolor = *PL_colors[0] || *PL_colors[2] || *PL_colors[4];
+    const int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */
+    int l = (loc_regeol - locinput) > taill ? taill : (loc_regeol - locinput);
+    /* The part of the string before starttry has one color
+       (pref0_len chars), between starttry and current
+       position another one (pref_len - pref0_len chars),
+       after the current position the third one.
+       We assume that pref0_len <= pref_len, otherwise we
+       decrease pref0_len.  */
+    int pref_len = (locinput - loc_bostr) > (5 + taill) - l
+       ? (5 + taill) - l : locinput - loc_bostr;
+    int pref0_len;
+
+    PERL_ARGS_ASSERT_DUMP_EXEC_POS;
+
+    while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput - pref_len)))
+       pref_len++;
+    pref0_len = pref_len  - (locinput - loc_reg_starttry);
+    if (l + pref_len < (5 + taill) && l < loc_regeol - locinput)
+       l = ( loc_regeol - locinput > (5 + taill) - pref_len
+             ? (5 + taill) - pref_len : loc_regeol - locinput);
+    while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput + l)))
+       l--;
+    if (pref0_len < 0)
+       pref0_len = 0;
+    if (pref0_len > pref_len)
+       pref0_len = pref_len;
+    {
+       const int is_uni = (utf8_target && OP(scan) != CANY) ? 1 : 0;
+
+       RE_PV_COLOR_DECL(s0,len0,is_uni,PERL_DEBUG_PAD(0),
+           (locinput - pref_len),pref0_len, 60, 4, 5);
+       
+       RE_PV_COLOR_DECL(s1,len1,is_uni,PERL_DEBUG_PAD(1),
+                   (locinput - pref_len + pref0_len),
+                   pref_len - pref0_len, 60, 2, 3);
+       
+       RE_PV_COLOR_DECL(s2,len2,is_uni,PERL_DEBUG_PAD(2),
+                   locinput, loc_regeol - locinput, 10, 0, 1);
+
+       const STRLEN tlen=len0+len1+len2;
+       PerlIO_printf(Perl_debug_log,
+                   "%4"IVdf" <%.*s%.*s%s%.*s>%*s|",
+                   (IV)(locinput - loc_bostr),
+                   len0, s0,
+                   len1, s1,
+                   (docolor ? "" : "> <"),
+                   len2, s2,
+                   (int)(tlen > 19 ? 0 :  19 - tlen),
+                   "");
+    }
+}
+
+#endif
+
+/* reg_check_named_buff_matched()
+ * Checks to see if a named buffer has matched. The data array of 
+ * buffer numbers corresponding to the buffer is expected to reside
+ * in the regexp->data->data array in the slot stored in the ARG() of
+ * node involved. Note that this routine doesn't actually care about the
+ * name, that information is not preserved from compilation to execution.
+ * Returns the index of the leftmost defined buffer with the given name
+ * or 0 if non of the buffers matched.
+ */
+STATIC I32
+S_reg_check_named_buff_matched(pTHX_ const regexp *rex, const regnode *scan)
+{
+    I32 n;
+    RXi_GET_DECL(rex,rexi);
+    SV *sv_dat= MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
+    I32 *nums=(I32*)SvPVX(sv_dat);
+
+    PERL_ARGS_ASSERT_REG_CHECK_NAMED_BUFF_MATCHED;
+
+    for ( n=0; n<SvIVX(sv_dat); n++ ) {
+        if ((I32)*PL_reglastparen >= nums[n] &&
+            PL_regoffs[nums[n]].end != -1)
+        {
+            return nums[n];
+        }
+    }
+    return 0;
+}
+
+
+/* free all slabs above current one  - called during LEAVE_SCOPE */
+
+STATIC void
+S_clear_backtrack_stack(pTHX_ void *p)
+{
+    regmatch_slab *s = PL_regmatch_slab->next;
+    PERL_UNUSED_ARG(p);
+
+    if (!s)
+       return;
+    PL_regmatch_slab->next = NULL;
+    while (s) {
+       regmatch_slab * const osl = s;
+       s = s->next;
+       Safefree(osl);
+    }
+}
+
+
+#define SETREX(Re1,Re2) \
+    if (PL_reg_eval_set) PM_SETRE((PL_reg_curpm), (Re2)); \
+    Re1 = (Re2)
+
 STATIC I32                     /* 0 failure, 1 success */
-S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
+S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
 {
-#if PERL_VERSION < 9
+#if PERL_VERSION < 9 && !defined(PERL_CORE)
     dMY_CXT;
 #endif
     dVAR;
-    register const bool do_utf8 = PL_reg_match_utf8;
+    register const bool utf8_target = PL_reg_match_utf8;
     const U32 uniflags = UTF8_ALLOW_DEFAULT;
-
-    regexp *rex = reginfo->prog;
-
-    regmatch_slab  *orig_slab;
-    regmatch_state *orig_state;
-
+    REGEXP *rex_sv = reginfo->prog;
+    regexp *rex = (struct regexp *)SvANY(rex_sv);
+    RXi_GET_DECL(rex,rexi);
+    I32        oldsave;
     /* the current state. This is a cached copy of PL_regmatch_state */
     register regmatch_state *st;
-
     /* cache heavy used fields of st in registers */
     register regnode *scan;
     register regnode *next;
-    register I32 n = 0;        /* initialize to shut up compiler warning */
+    register U32 n = 0;        /* general value; init to avoid compiler warning */
+    register I32 ln = 0; /* len or last;  init to avoid compiler warning */
     register char *locinput = PL_reginput;
-
-    /* these variables are NOT saved during a recusive RFEGMATCH: */
     register I32 nextchr;   /* is always set to UCHARAT(locinput) */
-    bool result;           /* return value of S_regmatch */
-    regnode *inner;        /* Next node in internal branch. */
-    int depth = 0;         /* depth of recursion */
-    regmatch_state *newst;  /* when pushing a state, this is the new one */
+
+    bool result = 0;       /* return value of S_regmatch */
+    int depth = 0;         /* depth of backtrack stack */
+    U32 nochange_depth = 0; /* depth of GOSUB recursion with nochange */
+    const U32 max_nochange_depth =
+        (3 * rex->nparens > MAX_RECURSE_EVAL_NOCHANGE_DEPTH) ?
+        3 * rex->nparens : MAX_RECURSE_EVAL_NOCHANGE_DEPTH;
     regmatch_state *yes_state = NULL; /* state to pop to on success of
                                                            subpattern */
-    
+    /* mark_state piggy backs on the yes_state logic so that when we unwind 
+       the stack on success we can update the mark_state as we go */
+    regmatch_state *mark_state = NULL; /* last mark state we have seen */
+    regmatch_state *cur_eval = NULL; /* most recent EVAL_AB state */
+    struct regmatch_state  *cur_curlyx = NULL; /* most recent curlyx */
+    U32 state_num;
+    bool no_final = 0;      /* prevent failure from backtracking? */
+    bool do_cutgroup = 0;   /* no_final only until next branch/trie entry */
+    char *startpoint = PL_reginput;
+    SV *popmark = NULL;     /* are we looking for a mark? */
+    SV *sv_commit = NULL;   /* last mark name seen in failure */
+    SV *sv_yes_mark = NULL; /* last mark name we have seen 
+                               during a successfull match */
+    U32 lastopen = 0;       /* last open we saw */
+    bool has_cutgroup = RX_HAS_CUTGROUP(rex) ? 1 : 0;   
+    SV* const oreplsv = GvSV(PL_replgv);
+    /* these three flags are set by various ops to signal information to
+     * the very next op. They have a useful lifetime of exactly one loop
+     * iteration, and are not preserved or restored by state pushes/pops
+     */
+    bool sw = 0;           /* the condition value in (?(cond)a|b) */
+    bool minmod = 0;       /* the next "{n,m}" is a "{n,m}?" */
+    int logical = 0;       /* the following EVAL is:
+                               0: (?{...})
+                               1: (?(?{...})X|Y)
+                               2: (??{...})
+                              or the following IFMATCH/UNLESSM is:
+                               false: plain (?=foo)
+                               true:  used as a condition: (?(?=foo))
+                           */
 #ifdef DEBUGGING
-    SV *re_debug_flags = NULL;
-    GET_RE_DEBUG_FLAGS;
-    PL_regindent++;
+    GET_RE_DEBUG_FLAGS_DECL;
 #endif
 
+    PERL_ARGS_ASSERT_REGMATCH;
+
+    DEBUG_OPTIMISE_r( DEBUG_EXECUTE_r({
+           PerlIO_printf(Perl_debug_log,"regmatch start\n");
+    }));
     /* on first ever call to regmatch, allocate first slab */
     if (!PL_regmatch_slab) {
        Newx(PL_regmatch_slab, 1, regmatch_slab);
@@ -2507,21 +2924,16 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
        PL_regmatch_state = SLAB_FIRST(PL_regmatch_slab);
     }
 
-    /* remember current high-water mark for exit */
-    /* XXX this should be done with SAVE* instead */
-    orig_slab  = PL_regmatch_slab;
-    orig_state = PL_regmatch_state;
+    oldsave = PL_savestack_ix;
+    SAVEDESTRUCTOR_X(S_clear_backtrack_stack, NULL);
+    SAVEVPTR(PL_regmatch_slab);
+    SAVEVPTR(PL_regmatch_state);
 
     /* grab next free state slot */
     st = ++PL_regmatch_state;
     if (st >  SLAB_LAST(PL_regmatch_slab))
        st = PL_regmatch_state = S_push_slab(aTHX);
 
-    st->minmod = 0;
-    st->sw = 0;
-    st->logical = 0;
-    st->unwind = 0;
-    st->cc = NULL;
     /* Note that nextchr is a byte even in UTF */
     nextchr = UCHARAT(locinput);
     scan = prog;
@@ -2529,75 +2941,30 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
 
         DEBUG_EXECUTE_r( {
            SV * const prop = sv_newmortal();
-           const int docolor = *PL_colors[0];
-           const int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */
-           int l = (PL_regeol - locinput) > taill ? taill : (PL_regeol - locinput);
-           /* The part of the string before starttry has one color
-              (pref0_len chars), between starttry and current
-              position another one (pref_len - pref0_len chars),
-              after the current position the third one.
-              We assume that pref0_len <= pref_len, otherwise we
-              decrease pref0_len.  */
-           int pref_len = (locinput - PL_bostr) > (5 + taill) - l
-               ? (5 + taill) - l : locinput - PL_bostr;
-           int pref0_len;
-
-           while (do_utf8 && UTF8_IS_CONTINUATION(*(U8*)(locinput - pref_len)))
-               pref_len++;
-           pref0_len = pref_len  - (locinput - PL_reg_starttry);
-           if (l + pref_len < (5 + taill) && l < PL_regeol - locinput)
-               l = ( PL_regeol - locinput > (5 + taill) - pref_len
-                     ? (5 + taill) - pref_len : PL_regeol - locinput);
-           while (do_utf8 && UTF8_IS_CONTINUATION(*(U8*)(locinput + l)))
-               l--;
-           if (pref0_len < 0)
-               pref0_len = 0;
-           if (pref0_len > pref_len)
-               pref0_len = pref_len;
+           regnode *rnext=regnext(scan);
+           DUMP_EXEC_POS( locinput, scan, utf8_target );
            regprop(rex, prop, scan);
-           {
-             const char * const s0 =
-               do_utf8 && OP(scan) != CANY ?
-               pv_uni_display(PERL_DEBUG_PAD(0), (U8*)(locinput - pref_len),
-                              pref0_len, 60, UNI_DISPLAY_REGEX) :
-               locinput - pref_len;
-             const int len0 = do_utf8 ? strlen(s0) : pref0_len;
-             const char * const s1 = do_utf8 && OP(scan) != CANY ?
-               pv_uni_display(PERL_DEBUG_PAD(1),
-                              (U8*)(locinput - pref_len + pref0_len),
-                              pref_len - pref0_len, 60, UNI_DISPLAY_REGEX) :
-               locinput - pref_len + pref0_len;
-             const int len1 = do_utf8 ? strlen(s1) : pref_len - pref0_len;
-             const char * const s2 = do_utf8 && OP(scan) != CANY ?
-               pv_uni_display(PERL_DEBUG_PAD(2), (U8*)locinput,
-                              PL_regeol - locinput, 60, UNI_DISPLAY_REGEX) :
-               locinput;
-             const int len2 = do_utf8 ? strlen(s2) : l;
-             PerlIO_printf(Perl_debug_log,
-                           "%4"IVdf" <%s%.*s%s%s%.*s%s%s%s%.*s%s>%*s|%3"IVdf":%*s%s\n",
-                           (IV)(locinput - PL_bostr),
-                           PL_colors[4],
-                           len0, s0,
-                           PL_colors[5],
-                           PL_colors[2],
-                           len1, s1,
-                           PL_colors[3],
-                           (docolor ? "" : "> <"),
-                           PL_colors[0],
-                           len2, s2,
-                           PL_colors[1],
-                           15 - l - pref_len + 1,
-                           "",
-                           (IV)(scan - rex->program), PL_regindent*2, "",
-                           SvPVX_const(prop));
-           }
+            
+           PerlIO_printf(Perl_debug_log,
+                   "%3"IVdf":%*s%s(%"IVdf")\n",
+                   (IV)(scan - rexi->program), depth*2, "",
+                   SvPVX_const(prop),
+                   (PL_regkind[OP(scan)] == END || !rnext) ? 
+                       0 : (IV)(rnext - rexi->program));
        });
 
        next = scan + NEXT_OFF(scan);
        if (next == scan)
            next = NULL;
+       state_num = OP(scan);
+
+      reenter_switch:
 
-       switch (OP(scan)) {
+       assert(PL_reglastparen == &rex->lastparen);
+       assert(PL_reglastcloseparen == &rex->lastcloseparen);
+       assert(PL_regoffs == rex->offs);
+
+       switch (state_num) {
        case BOL:
            if (locinput == PL_bostr)
            {
@@ -2620,6 +2987,19 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
            if (locinput == reginfo->ganch)
                break;
            sayNO;
+
+       case KEEPS:
+           /* update the startpoint */
+           st->u.keeper.val = PL_regoffs[0].start;
+           PL_reginput = locinput;
+           PL_regoffs[0].start = locinput - PL_bostr;
+           PUSH_STATE_GOTO(KEEPS_next, next);
+           /*NOT-REACHED*/
+       case KEEPS_next_fail:
+           /* rollback the start point change */
+           PL_regoffs[0].start = st->u.keeper.val;
+           sayNO_SILENT;
+           /*NOT-REACHED*/
        case EOL:
                goto seol;
        case MEOL:
@@ -2640,7 +3020,7 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
        case SANY:
            if (!nextchr && locinput >= PL_regeol)
                sayNO;
-           if (do_utf8) {
+           if (utf8_target) {
                locinput += PL_utf8skip[nextchr];
                if (locinput > PL_regeol)
                    sayNO;
@@ -2657,7 +3037,7 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
        case REG_ANY:
            if ((!nextchr && locinput >= PL_regeol) || nextchr == '\n')
                sayNO;
-           if (do_utf8) {
+           if (utf8_target) {
                locinput += PL_utf8skip[nextchr];
                if (locinput > PL_regeol)
                    sayNO;
@@ -2667,132 +3047,175 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                nextchr = UCHARAT(++locinput);
            break;
 
-
-
-       /*
-          traverse the TRIE keeping track of all accepting states
-          we transition through until we get to a failing node.
-
-
-       */
+#undef  ST
+#define ST st->u.trie
+        case TRIEC:
+            /* In this case the charclass data is available inline so
+               we can fail fast without a lot of extra overhead. 
+             */
+            if (scan->flags == EXACT || !utf8_target) {
+                if(!ANYOF_BITMAP_TEST(scan, *locinput)) {
+                    DEBUG_EXECUTE_r(
+                        PerlIO_printf(Perl_debug_log,
+                                 "%*s  %sfailed to match trie start class...%s\n",
+                                 REPORT_CODE_OFF+depth*2, "", PL_colors[4], PL_colors[5])
+                    );
+                    sayNO_SILENT;
+                    /* NOTREACHED */
+                }                      
+            }
+            /* FALL THROUGH */
        case TRIE:
-       case TRIEF:
-       case TRIEFL:
+           /* the basic plan of execution of the trie is:
+            * At the beginning, run though all the states, and
+            * find the longest-matching word. Also remember the position
+            * of the shortest matching word. For example, this pattern:
+            *    1  2 3 4    5
+            *    ab|a|x|abcd|abc
+            * when matched against the string "abcde", will generate
+            * accept states for all words except 3, with the longest
+            * matching word being 4, and the shortest being 1 (with
+            * the position being after char 1 of the string).
+            *
+            * Then for each matching word, in word order (i.e. 1,2,4,5),
+            * we run the remainder of the pattern; on each try setting
+            * the current position to the character following the word,
+            * returning to try the next word on failure.
+            *
+            * We avoid having to build a list of words at runtime by
+            * using a compile-time structure, wordinfo[].prev, which
+            * gives, for each word, the previous accepting word (if any).
+            * In the case above it would contain the mappings 1->2, 2->0,
+            * 3->0, 4->5, 5->1.  We can use this table to generate, from
+            * the longest word (4 above), a list of all words, by
+            * following the list of prev pointers; this gives us the
+            * unordered list 4,5,1,2. Then given the current word we have
+            * just tried, we can go through the list and find the
+            * next-biggest word to try (so if we just failed on word 2,
+            * the next in the list is 4).
+            *
+            * Since at runtime we don't record the matching position in
+            * the string for each word, we have to work that out for
+            * each word we're about to process. The wordinfo table holds
+            * the character length of each word; given that we recorded
+            * at the start: the position of the shortest word and its
+            * length in chars, we just need to move the pointer the
+            * difference between the two char lengths. Depending on
+            * Unicode status and folding, that's cheap or expensive.
+            *
+            * This algorithm is optimised for the case where are only a
+            * small number of accept states, i.e. 0,1, or maybe 2.
+            * With lots of accepts states, and having to try all of them,
+            * it becomes quadratic on number of accept states to find all
+            * the next words.
+            */
+
            {
+                /* what type of TRIE am I? (utf8 makes this contextual) */
+                DECL_TRIE_TYPE(scan);
+
+                /* what trie are we using right now */
+               reg_trie_data * const trie
+                   = (reg_trie_data*)rexi->data->data[ ARG( scan ) ];
+               HV * widecharmap = MUTABLE_HV(rexi->data->data[ ARG( scan ) + 1 ]);
+                U32 state = trie->startstate;
+
+               if (trie->bitmap && trie_type != trie_utf8_fold &&
+                   !TRIE_BITMAP_TEST(trie,*locinput)
+               ) {
+                   if (trie->states[ state ].wordnum) {
+                        DEBUG_EXECUTE_r(
+                            PerlIO_printf(Perl_debug_log,
+                                         "%*s  %smatched empty string...%s\n",
+                                         REPORT_CODE_OFF+depth*2, "", PL_colors[4], PL_colors[5])
+                        );
+                       break;
+                   } else {
+                       DEBUG_EXECUTE_r(
+                            PerlIO_printf(Perl_debug_log,
+                                         "%*s  %sfailed to match trie start class...%s\n",
+                                         REPORT_CODE_OFF+depth*2, "", PL_colors[4], PL_colors[5])
+                        );
+                       sayNO_SILENT;
+                  }
+                }
+
+            { 
                U8 *uc = ( U8* )locinput;
-               U32 state = 1;
-               U16 charid = 0;
-               U32 base = 0;
-               UV uvc = 0;
+
                STRLEN len = 0;
                STRLEN foldlen = 0;
                U8 *uscan = (U8*)NULL;
-               STRLEN bufflen=0;
-               SV *sv_accept_buff = NULL;
-               const enum { trie_plain, trie_utf8, trie_uft8_fold }
-                   trie_type = do_utf8 ?
-                         (OP(scan) == TRIE ? trie_utf8 : trie_uft8_fold)
-                       : trie_plain;
-
-               /* what trie are we using right now */
-               reg_trie_data *trie
-                   = (reg_trie_data*)rex->data->data[ ARG( scan ) ];
-               st->u.trie.accepted = 0; /* how many accepting states we have seen */
-               result = 0;
+               U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
+               U32 charcount = 0; /* how many input chars we have matched */
+               U32 accepted = 0; /* have we seen any accepting states? */
 
-               while ( state && uc <= (U8*)PL_regeol ) {
+               ST.B = next;
+               ST.jump = trie->jump;
+               ST.me = scan;
+               ST.firstpos = NULL;
+               ST.longfold = FALSE; /* char longer if folded => it's harder */
+               ST.nextword = 0;
 
-                   if (trie->states[ state ].wordnum) {
-                       if (!st->u.trie.accepted ) {
-                           ENTER;
-                           SAVETMPS;
-                           bufflen = TRIE_INITAL_ACCEPT_BUFFLEN;
-                           sv_accept_buff=newSV(bufflen *
-                                           sizeof(reg_trie_accepted) - 1);
-                           SvCUR_set(sv_accept_buff,
-                                               sizeof(reg_trie_accepted));
-                           SvPOK_on(sv_accept_buff);
-                           sv_2mortal(sv_accept_buff);
-                           st->u.trie.accept_buff =
-                               (reg_trie_accepted*)SvPV_nolen(sv_accept_buff );
-                       }
-                       else {
-                           if (st->u.trie.accepted >= bufflen) {
-                               bufflen *= 2;
-                               st->u.trie.accept_buff =(reg_trie_accepted*)
-                                   SvGROW(sv_accept_buff,
-                                       bufflen * sizeof(reg_trie_accepted));
+               /* fully traverse the TRIE; note the position of the
+                  shortest accept state and the wordnum of the longest
+                  accept state */
+
+               while ( state && uc <= (U8*)PL_regeol ) {
+                    U32 base = trie->states[ state ].trans.base;
+                    UV uvc = 0;
+                    U16 charid;
+                   U16 wordnum;
+                    wordnum = trie->states[ state ].wordnum;
+
+                   if (wordnum) { /* it's an accept state */
+                       if (!accepted) {
+                           accepted = 1;
+                           /* record first match position */
+                           if (ST.longfold) {
+                               ST.firstpos = (U8*)locinput;
+                               ST.firstchars = 0;
+                           }
+                           else {
+                               ST.firstpos = uc;
+                               ST.firstchars = charcount;
                            }
-                           SvCUR_set(sv_accept_buff,SvCUR(sv_accept_buff)
-                               + sizeof(reg_trie_accepted));
                        }
-                       st->u.trie.accept_buff[st->u.trie.accepted].wordnum = trie->states[state].wordnum;
-                       st->u.trie.accept_buff[st->u.trie.accepted].endpos = uc;
-                       ++st->u.trie.accepted;
+                       if (!ST.nextword || wordnum < ST.nextword)
+                           ST.nextword = wordnum;
+                       ST.topword = wordnum;
                    }
 
-                   base = trie->states[ state ].trans.base;
-
-                   DEBUG_TRIE_EXECUTE_r(
+                   DEBUG_TRIE_EXECUTE_r({
+                               DUMP_EXEC_POS( (char *)uc, scan, utf8_target );
                                PerlIO_printf( Perl_debug_log,
-                                   "%*s  %sState: %4"UVxf", Base: %4"UVxf", Accepted: %4"UVxf" ",
-                                   REPORT_CODE_OFF + PL_regindent * 2, "", PL_colors[4],
-                                   (UV)state, (UV)base, (UV)st->u.trie.accepted );
-                   );
+                                   "%*s  %sState: %4"UVxf" Accepted: %c ",
+                                   2+depth * 2, "", PL_colors[4],
+                                   (UV)state, (accepted ? 'Y' : 'N'));
+                   });
 
+                   /* read a char and goto next state */
                    if ( base ) {
-                       switch (trie_type) {
-                       case trie_uft8_fold:
-                           if ( foldlen>0 ) {
-                               uvc = utf8n_to_uvuni( uscan, UTF8_MAXLEN, &len, uniflags );
-                               foldlen -= len;
-                               uscan += len;
-                               len=0;
-                           } else {
-                               U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
-                               uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN, &len, uniflags );
-                               uvc = to_uni_fold( uvc, foldbuf, &foldlen );
-                               foldlen -= UNISKIP( uvc );
-                               uscan = foldbuf + UNISKIP( uvc );
-                           }
-                           break;
-                       case trie_utf8:
-                           uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN,
-                                                           &len, uniflags );
-                           break;
-                       case trie_plain:
-                           uvc = (UV)*uc;
-                           len = 1;
-                       }
+                       I32 offset;
+                       REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc,
+                                            uscan, len, uvc, charid, foldlen,
+                                            foldbuf, uniflags);
+                       charcount++;
+                       if (foldlen>0)
+                           ST.longfold = TRUE;
+                       if (charid &&
+                            ( ((offset =
+                             base + charid - 1 - trie->uniquecharcount)) >= 0)
 
-                       if (uvc < 256) {
-                           charid = trie->charmap[ uvc ];
+                            && ((U32)offset < trie->lasttrans)
+                            && trie->trans[offset].check == state)
+                       {
+                           state = trie->trans[offset].next;
                        }
                        else {
-                           charid = 0;
-                           if (trie->widecharmap) {
-                               SV** svpp = (SV**)NULL;
-                               svpp = hv_fetch(trie->widecharmap,
-                                           (char*)&uvc, sizeof(UV), 0);
-                               if (svpp)
-                                   charid = (U16)SvIV(*svpp);
-                           }
+                           state = 0;
                        }
-
-                       if (charid &&
-                            (base + charid > trie->uniquecharcount )
-                            && (base + charid - 1 - trie->uniquecharcount
-                                   < trie->lasttrans)
-                            && trie->trans[base + charid - 1 -
-                                   trie->uniquecharcount].check == state)
-                       {
-                           state = trie->trans[base + charid - 1 -
-                               trie->uniquecharcount ].next;
-                       }
-                       else {
-                           state = 0;
-                       }
-                       uc += len;
+                       uc += len;
 
                    }
                    else {
@@ -2800,113 +3223,183 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                    }
                    DEBUG_TRIE_EXECUTE_r(
                        PerlIO_printf( Perl_debug_log,
-                           "Charid:%3x CV:%4"UVxf" After State: %4"UVxf"%s\n",
+                           "Charid:%3x CP:%4"UVxf" After State: %4"UVxf"%s\n",
                            charid, uvc, (UV)state, PL_colors[5] );
                    );
                }
-               if (!st->u.trie.accepted )
+               if (!accepted)
                   sayNO;
 
-           /*
-              There was at least one accepting state that we
-              transitioned through. Presumably the number of accepting
-              states is going to be low, typically one or two. So we
-              simply scan through to find the one with lowest wordnum.
-              Once we find it, we swap the last state into its place
-              and decrement the size. We then try to match the rest of
-              the pattern at the point where the word ends, if we
-              succeed then we end the loop, otherwise the loop
-              eventually terminates once all of the accepting states
-              have been tried.
-           */
+               /* calculate total number of accept states */
+               {
+                   U16 w = ST.topword;
+                   accepted = 0;
+                   while (w) {
+                       w = trie->wordinfo[w].prev;
+                       accepted++;
+                   }
+                   ST.accepted = accepted;
+               }
 
-               if ( st->u.trie.accepted == 1 ) {
-                   DEBUG_EXECUTE_r({
-                        SV ** const tmp = av_fetch( trie->words, st->u.trie.accept_buff[ 0 ].wordnum-1, 0 );
-                               PerlIO_printf( Perl_debug_log,
-                           "%*s  %sonly one match : #%d <%s>%s\n",
-                           REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4],
-                           st->u.trie.accept_buff[ 0 ].wordnum,
-                           tmp ? SvPV_nolen_const( *tmp ) : "not compiled under -Dr",
-                           PL_colors[5] );
-                   });
-                   PL_reginput = (char *)st->u.trie.accept_buff[ 0 ].endpos;
-                   /* in this case we free tmps/leave before we call regmatch
-                      as we wont be using accept_buff again. */
-                   FREETMPS;
-                   LEAVE;
-                   REGMATCH(scan + NEXT_OFF(scan), TRIE1);
-                   /*** all unsaved local vars undefined at this point */
-               } else {
-                    DEBUG_EXECUTE_r(
-                        PerlIO_printf( Perl_debug_log,"%*s  %sgot %"IVdf" possible matches%s\n",
-                            REPORT_CODE_OFF + PL_regindent * 2, "", PL_colors[4], (IV)st->u.trie.accepted,
-                            PL_colors[5] );
-                    );
-                   while ( !result && st->u.trie.accepted-- ) {
-                       U32 best = 0;
-                       U32 cur;
-                       for( cur = 1 ; cur <= st->u.trie.accepted ; cur++ ) {
-                           DEBUG_TRIE_EXECUTE_r(
-                               PerlIO_printf( Perl_debug_log,
-                                   "%*s  %sgot %"IVdf" (%d) as best, looking at %"IVdf" (%d)%s\n",
-                                   REPORT_CODE_OFF + PL_regindent * 2, "", PL_colors[4],
-                                   (IV)best, st->u.trie.accept_buff[ best ].wordnum, (IV)cur,
-                                   st->u.trie.accept_buff[ cur ].wordnum, PL_colors[5] );
-                           );
-
-                           if (st->u.trie.accept_buff[cur].wordnum <
-                                   st->u.trie.accept_buff[best].wordnum)
-                               best = cur;
+               DEBUG_EXECUTE_r(
+                   PerlIO_printf( Perl_debug_log,
+                       "%*s  %sgot %"IVdf" possible matches%s\n",
+                       REPORT_CODE_OFF + depth * 2, "",
+                       PL_colors[4], (IV)ST.accepted, PL_colors[5] );
+               );
+               goto trie_first_try; /* jump into the fail handler */
+           }}
+           /* NOTREACHED */
+
+       case TRIE_next_fail: /* we failed - try next alternative */
+            if ( ST.jump) {
+                REGCP_UNWIND(ST.cp);
+               for (n = *PL_reglastparen; n > ST.lastparen; n--)
+                   PL_regoffs[n].end = -1;
+               *PL_reglastparen = n;
+           }
+           if (!--ST.accepted) {
+               DEBUG_EXECUTE_r({
+                   PerlIO_printf( Perl_debug_log,
+                       "%*s  %sTRIE failed...%s\n",
+                       REPORT_CODE_OFF+depth*2, "", 
+                       PL_colors[4],
+                       PL_colors[5] );
+               });
+               sayNO_SILENT;
+           }
+           {
+               /* Find next-highest word to process.  Note that this code
+                * is O(N^2) per trie run (O(N) per branch), so keep tight */
+               register U16 min = 0;
+               register U16 word;
+               register U16 const nextword = ST.nextword;
+               register reg_trie_wordinfo * const wordinfo
+                   = ((reg_trie_data*)rexi->data->data[ARG(ST.me)])->wordinfo;
+               for (word=ST.topword; word; word=wordinfo[word].prev) {
+                   if (word > nextword && (!min || word < min))
+                       min = word;
+               }
+               ST.nextword = min;
+           }
+
+          trie_first_try:
+            if (do_cutgroup) {
+                do_cutgroup = 0;
+                no_final = 0;
+            }
+
+            if ( ST.jump) {
+                ST.lastparen = *PL_reglastparen;
+               REGCP_SET(ST.cp);
+            }
+
+           /* find start char of end of current word */
+           {
+               U32 chars; /* how many chars to skip */
+               U8 *uc = ST.firstpos;
+               reg_trie_data * const trie
+                   = (reg_trie_data*)rexi->data->data[ARG(ST.me)];
+
+               assert((trie->wordinfo[ST.nextword].len - trie->prefixlen)
+                           >=  ST.firstchars);
+               chars = (trie->wordinfo[ST.nextword].len - trie->prefixlen)
+                           - ST.firstchars;
+
+               if (ST.longfold) {
+                   /* the hard option - fold each char in turn and find
+                    * its folded length (which may be different */
+                   U8 foldbuf[UTF8_MAXBYTES_CASE + 1];
+                   STRLEN foldlen;
+                   STRLEN len;
+                   UV uvc;
+                   U8 *uscan;
+
+                   while (chars) {
+                       if (utf8_target) {
+                           uvc = utf8n_to_uvuni((U8*)uc, UTF8_MAXLEN, &len,
+                                                   uniflags);
+                           uc += len;
                        }
-                       DEBUG_EXECUTE_r({
-                           reg_trie_data * const trie = (reg_trie_data*)
-                                           rex->data->data[ARG(scan)];
-                           SV ** const tmp = av_fetch( trie->words, st->u.trie.accept_buff[ best ].wordnum - 1, 0 );
-                           PerlIO_printf( Perl_debug_log, "%*s  %strying alternation #%d <%s> at 0x%p%s\n",
-                               REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4],
-                               st->u.trie.accept_buff[best].wordnum,
-                               tmp ? SvPV_nolen_const( *tmp ) : "not compiled under -Dr",scan,
-                               PL_colors[5] );
-                       });
-                       if ( best<st->u.trie.accepted ) {
-                           reg_trie_accepted tmp = st->u.trie.accept_buff[ best ];
-                           st->u.trie.accept_buff[ best ] = st->u.trie.accept_buff[ st->u.trie.accepted ];
-                           st->u.trie.accept_buff[ st->u.trie.accepted ] = tmp;
-                           best = st->u.trie.accepted;
+                       else {
+                           uvc = *uc;
+                           uc++;
+                       }
+                       uvc = to_uni_fold(uvc, foldbuf, &foldlen);
+                       uscan = foldbuf;
+                       while (foldlen) {
+                           if (!--chars)
+                               break;
+                           uvc = utf8n_to_uvuni(uscan, UTF8_MAXLEN, &len,
+                                           uniflags);
+                           uscan += len;
+                           foldlen -= len;
                        }
-                       PL_reginput = (char *)st->u.trie.accept_buff[ best ].endpos;
-
-                        /* 
-                           as far as I can tell we only need the SAVETMPS/FREETMPS 
-                           for re's with EVAL in them but I'm leaving them in for 
-                           all until I can be sure.
-                         */
-                       SAVETMPS;
-                       REGMATCH(scan + NEXT_OFF(scan), TRIE2);
-                       /*** all unsaved local vars undefined at this point */
-                       FREETMPS;
                    }
-                   FREETMPS;
-                   LEAVE;
                }
-               
-               if (result) {
-                   sayYES;
-               } else {
-                   sayNO;
+               else {
+                   if (utf8_target)
+                       while (chars--)
+                           uc += UTF8SKIP(uc);
+                   else
+                       uc += chars;
                }
+               PL_reginput = (char *)uc;
            }
-           /* unreached codepoint */
+
+           scan = (ST.jump && ST.jump[ST.nextword]) 
+                       ? ST.me + ST.jump[ST.nextword]
+                       : ST.B;
+
+           DEBUG_EXECUTE_r({
+               PerlIO_printf( Perl_debug_log,
+                   "%*s  %sTRIE matched word #%d, continuing%s\n",
+                   REPORT_CODE_OFF+depth*2, "", 
+                   PL_colors[4],
+                   ST.nextword,
+                   PL_colors[5]
+                   );
+           });
+
+           if (ST.accepted > 1 || has_cutgroup) {
+               PUSH_STATE_GOTO(TRIE_next, scan);
+               /* NOTREACHED */
+           }
+           /* only one choice left - just continue */
+           DEBUG_EXECUTE_r({
+               AV *const trie_words
+                   = MUTABLE_AV(rexi->data->data[ARG(ST.me)+TRIE_WORDS_OFFSET]);
+               SV ** const tmp = av_fetch( trie_words,
+                   ST.nextword-1, 0 );
+               SV *sv= tmp ? sv_newmortal() : NULL;
+
+               PerlIO_printf( Perl_debug_log,
+                   "%*s  %sonly one match left, short-circuiting: #%d <%s>%s\n",
+                   REPORT_CODE_OFF+depth*2, "", PL_colors[4],
+                   ST.nextword,
+                   tmp ? pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp), 0,
+                           PL_colors[0], PL_colors[1],
+                           (SvUTF8(*tmp) ? PERL_PV_ESCAPE_UNI : 0)
+                       ) 
+                   : "not compiled under -Dr",
+                   PL_colors[5] );
+           });
+
+           locinput = PL_reginput;
+           nextchr = UCHARAT(locinput);
+           continue; /* execute rest of RE */
+           /* NOTREACHED */
+#undef  ST
+
        case EXACT: {
            char *s = STRING(scan);
-           st->ln = STR_LEN(scan);
-           if (do_utf8 != UTF) {
+           ln = STR_LEN(scan);
+           if (utf8_target != UTF_PATTERN) {
                /* The target and the pattern have differing utf8ness. */
                char *l = locinput;
-               const char *e = s + st->ln;
+               const char * const e = s + ln;
 
-               if (do_utf8) {
+               if (utf8_target) {
                    /* The target is utf8, the pattern is not utf8. */
                    while (s < e) {
                        STRLEN ulen;
@@ -2942,11 +3435,11 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
            /* Inline the first character, for speed. */
            if (UCHARAT(s) != nextchr)
                sayNO;
-           if (PL_regeol - locinput < st->ln)
+           if (PL_regeol - locinput < ln)
                sayNO;
-           if (st->ln > 1 && memNE(s, locinput, st->ln))
+           if (ln > 1 && memNE(s, locinput, ln))
                sayNO;
-           locinput += st->ln;
+           locinput += ln;
            nextchr = UCHARAT(locinput);
            break;
            }
@@ -2954,23 +3447,24 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
            PL_reg_flags |= RF_tainted;
            /* FALL THROUGH */
        case EXACTF: {
-           char *s = STRING(scan);
-           st->ln = STR_LEN(scan);
+           char * const s = STRING(scan);
+           ln = STR_LEN(scan);
 
-           if (do_utf8 || UTF) {
+           if (utf8_target || UTF_PATTERN) {
              /* Either target or the pattern are utf8. */
-               char *l = locinput;
+               const char * const l = locinput;
                char *e = PL_regeol;
 
-               if (ibcmp_utf8(s, 0,  st->ln, (bool)UTF,
-                              l, &e, 0,  do_utf8)) {
+               if (! foldEQ_utf8(s, 0,  ln, cBOOL(UTF_PATTERN),
+                              l, &e, 0,  utf8_target)) {
                     /* One more case for the sharp s:
                      * pack("U0U*", 0xDF) =~ /ss/i,
                      * the 0xC3 0x9F are the UTF-8
                      * byte sequence for the U+00DF. */
-                    if (!(do_utf8 &&
-                          toLOWER(s[0]) == 's' &&
-                          st->ln >= 2 &&
+
+                    if (!(utf8_target &&
+                          toLOWER(s[0]) == 's' &&
+                          ln >= 2 &&
                           toLOWER(s[1]) == 's' &&
                           (U8)l[0] == 0xC3 &&
                           e - l >= 2 &&
@@ -2989,95 +3483,16 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                UCHARAT(s) != ((OP(scan) == EXACTF)
                               ? PL_fold : PL_fold_locale)[nextchr])
                sayNO;
-           if (PL_regeol - locinput < st->ln)
+           if (PL_regeol - locinput < ln)
                sayNO;
-           if (st->ln > 1 && (OP(scan) == EXACTF
-                          ? ibcmp(s, locinput, st->ln)
-                          : ibcmp_locale(s, locinput, st->ln)))
+           if (ln > 1 && (OP(scan) == EXACTF
+                          ? ! foldEQ(s, locinput, ln)
+                          : ! foldEQ_locale(s, locinput, ln)))
                sayNO;
-           locinput += st->ln;
+           locinput += ln;
            nextchr = UCHARAT(locinput);
            break;
            }
-       case ANYOF:
-           if (do_utf8) {
-               STRLEN inclasslen = PL_regeol - locinput;
-
-               if (!reginclass(rex, scan, (U8*)locinput, &inclasslen, do_utf8))
-                   sayNO_ANYOF;
-               if (locinput >= PL_regeol)
-                   sayNO;
-               locinput += inclasslen ? inclasslen : UTF8SKIP(locinput);
-               nextchr = UCHARAT(locinput);
-               break;
-           }
-           else {
-               if (nextchr < 0)
-                   nextchr = UCHARAT(locinput);
-               if (!REGINCLASS(rex, scan, (U8*)locinput))
-                   sayNO_ANYOF;
-               if (!nextchr && locinput >= PL_regeol)
-                   sayNO;
-               nextchr = UCHARAT(++locinput);
-               break;
-           }
-       no_anyof:
-           /* If we might have the case of the German sharp s
-            * in a casefolding Unicode character class. */
-
-           if (ANYOF_FOLD_SHARP_S(scan, locinput, PL_regeol)) {
-                locinput += SHARP_S_SKIP;
-                nextchr = UCHARAT(locinput);
-           }
-           else
-                sayNO;
-           break;
-       case ALNUML:
-           PL_reg_flags |= RF_tainted;
-           /* FALL THROUGH */
-       case ALNUM:
-           if (!nextchr)
-               sayNO;
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_ALNUM();
-               if (!(OP(scan) == ALNUM
-                     ? swash_fetch(PL_utf8_alnum, (U8*)locinput, do_utf8)
-                     : isALNUM_LC_utf8((U8*)locinput)))
-               {
-                   sayNO;
-               }
-               locinput += PL_utf8skip[nextchr];
-               nextchr = UCHARAT(locinput);
-               break;
-           }
-           if (!(OP(scan) == ALNUM
-                 ? isALNUM(nextchr) : isALNUM_LC(nextchr)))
-               sayNO;
-           nextchr = UCHARAT(++locinput);
-           break;
-       case NALNUML:
-           PL_reg_flags |= RF_tainted;
-           /* FALL THROUGH */
-       case NALNUM:
-           if (!nextchr && locinput >= PL_regeol)
-               sayNO;
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_ALNUM();
-               if (OP(scan) == NALNUM
-                   ? swash_fetch(PL_utf8_alnum, (U8*)locinput, do_utf8)
-                   : isALNUM_LC_utf8((U8*)locinput))
-               {
-                   sayNO;
-               }
-               locinput += PL_utf8skip[nextchr];
-               nextchr = UCHARAT(locinput);
-               break;
-           }
-           if (OP(scan) == NALNUM
-               ? isALNUM(nextchr) : isALNUM_LC(nextchr))
-               sayNO;
-           nextchr = UCHARAT(++locinput);
-           break;
        case BOUNDL:
        case NBOUNDL:
            PL_reg_flags |= RF_tainted;
@@ -3085,182 +3500,339 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
        case BOUND:
        case NBOUND:
            /* was last char in word? */
-           if (do_utf8) {
+           if (utf8_target) {
                if (locinput == PL_bostr)
-                   st->ln = '\n';
+                   ln = '\n';
                else {
                    const U8 * const r = reghop3((U8*)locinput, -1, (U8*)PL_bostr);
-               
-                   st->ln = utf8n_to_uvchr(r, UTF8SKIP(r), 0, uniflags);
+
+                   ln = utf8n_to_uvchr(r, UTF8SKIP(r), 0, uniflags);
                }
                if (OP(scan) == BOUND || OP(scan) == NBOUND) {
-                   st->ln = isALNUM_uni(st->ln);
+                   ln = isALNUM_uni(ln);
                    LOAD_UTF8_CHARCLASS_ALNUM();
-                   n = swash_fetch(PL_utf8_alnum, (U8*)locinput, do_utf8);
+                   n = swash_fetch(PL_utf8_alnum, (U8*)locinput, utf8_target);
                }
                else {
-                   st->ln = isALNUM_LC_uvchr(UNI_TO_NATIVE(st->ln));
+                   ln = isALNUM_LC_uvchr(UNI_TO_NATIVE(ln));
                    n = isALNUM_LC_utf8((U8*)locinput);
                }
            }
            else {
-               st->ln = (locinput != PL_bostr) ?
+               ln = (locinput != PL_bostr) ?
                    UCHARAT(locinput - 1) : '\n';
                if (OP(scan) == BOUND || OP(scan) == NBOUND) {
-                   st->ln = isALNUM(st->ln);
+                   ln = isALNUM(ln);
                    n = isALNUM(nextchr);
                }
                else {
-                   st->ln = isALNUM_LC(st->ln);
+                   ln = isALNUM_LC(ln);
                    n = isALNUM_LC(nextchr);
                }
            }
-           if (((!st->ln) == (!n)) == (OP(scan) == BOUND ||
+           if (((!ln) == (!n)) == (OP(scan) == BOUND ||
                                    OP(scan) == BOUNDL))
                    sayNO;
            break;
-       case SPACEL:
-           PL_reg_flags |= RF_tainted;
-           /* FALL THROUGH */
-       case SPACE:
-           if (!nextchr)
-               sayNO;
-           if (do_utf8) {
-               if (UTF8_IS_CONTINUED(nextchr)) {
-                   LOAD_UTF8_CHARCLASS_SPACE();
-                   if (!(OP(scan) == SPACE
-                         ? swash_fetch(PL_utf8_space, (U8*)locinput, do_utf8)
-                         : isSPACE_LC_utf8((U8*)locinput)))
-                   {
-                       sayNO;
-                   }
-                   locinput += PL_utf8skip[nextchr];
-                   nextchr = UCHARAT(locinput);
-                   break;
-               }
-               if (!(OP(scan) == SPACE
-                     ? isSPACE(nextchr) : isSPACE_LC(nextchr)))
+       case ANYOF:
+           if (utf8_target) {
+               STRLEN inclasslen = PL_regeol - locinput;
+
+               if (!reginclass(rex, scan, (U8*)locinput, &inclasslen, utf8_target))
+                   goto anyof_fail;
+               if (locinput >= PL_regeol)
                    sayNO;
-               nextchr = UCHARAT(++locinput);
+               locinput += inclasslen ? inclasslen : UTF8SKIP(locinput);
+               nextchr = UCHARAT(locinput);
+               break;
            }
            else {
-               if (!(OP(scan) == SPACE
-                     ? isSPACE(nextchr) : isSPACE_LC(nextchr)))
+               if (nextchr < 0)
+                   nextchr = UCHARAT(locinput);
+               if (!REGINCLASS(rex, scan, (U8*)locinput))
+                   goto anyof_fail;
+               if (!nextchr && locinput >= PL_regeol)
                    sayNO;
                nextchr = UCHARAT(++locinput);
-           }
-           break;
-       case NSPACEL:
-           PL_reg_flags |= RF_tainted;
-           /* FALL THROUGH */
-       case NSPACE:
-           if (!nextchr && locinput >= PL_regeol)
-               sayNO;
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_SPACE();
-               if (OP(scan) == NSPACE
-                   ? swash_fetch(PL_utf8_space, (U8*)locinput, do_utf8)
-                   : isSPACE_LC_utf8((U8*)locinput))
-               {
-                   sayNO;
-               }
-               locinput += PL_utf8skip[nextchr];
-               nextchr = UCHARAT(locinput);
                break;
            }
-           if (OP(scan) == NSPACE
-               ? isSPACE(nextchr) : isSPACE_LC(nextchr))
-               sayNO;
-           nextchr = UCHARAT(++locinput);
-           break;
-       case DIGITL:
-           PL_reg_flags |= RF_tainted;
-           /* FALL THROUGH */
-       case DIGIT:
-           if (!nextchr)
-               sayNO;
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_DIGIT();
-               if (!(OP(scan) == DIGIT
-                     ? swash_fetch(PL_utf8_digit, (U8*)locinput, do_utf8)
-                     : isDIGIT_LC_utf8((U8*)locinput)))
-               {
-                   sayNO;
-               }
-               locinput += PL_utf8skip[nextchr];
-               nextchr = UCHARAT(locinput);
-               break;
+       anyof_fail:
+           /* If we might have the case of the German sharp s
+            * in a casefolding Unicode character class. */
+
+           if (ANYOF_FOLD_SHARP_S(scan, locinput, PL_regeol)) {
+                locinput += SHARP_S_SKIP;
+                nextchr = UCHARAT(locinput);
            }
-           if (!(OP(scan) == DIGIT
-                 ? isDIGIT(nextchr) : isDIGIT_LC(nextchr)))
-               sayNO;
-           nextchr = UCHARAT(++locinput);
+           else
+                sayNO;
            break;
-       case NDIGITL:
-           PL_reg_flags |= RF_tainted;
-           /* FALL THROUGH */
-       case NDIGIT:
-           if (!nextchr && locinput >= PL_regeol)
+       /* Special char classes - The defines start on line 129 or so */
+       CCC_TRY_AFF( ALNUM,  ALNUML, perl_word,   "a", isALNUM_LC_utf8, isALNUM, isALNUM_LC);
+       CCC_TRY_NEG(NALNUM, NALNUML, perl_word,   "a", isALNUM_LC_utf8, isALNUM, isALNUM_LC);
+
+       CCC_TRY_AFF( SPACE,  SPACEL, perl_space,  " ", isSPACE_LC_utf8, isSPACE, isSPACE_LC);
+       CCC_TRY_NEG(NSPACE, NSPACEL, perl_space,  " ", isSPACE_LC_utf8, isSPACE, isSPACE_LC);
+
+       CCC_TRY_AFF( DIGIT,  DIGITL, posix_digit, "0", isDIGIT_LC_utf8, isDIGIT, isDIGIT_LC);
+       CCC_TRY_NEG(NDIGIT, NDIGITL, posix_digit, "0", isDIGIT_LC_utf8, isDIGIT, isDIGIT_LC);
+
+       case CLUMP: /* Match \X: logical Unicode character.  This is defined as
+                      a Unicode extended Grapheme Cluster */
+           /* From http://www.unicode.org/reports/tr29 (5.2 version).  An
+             extended Grapheme Cluster is:
+
+              CR LF
+              | Prepend* Begin Extend*
+              | .
+
+              Begin is (Hangul-syllable | ! Control)
+              Extend is (Grapheme_Extend | Spacing_Mark)
+              Control is [ GCB_Control CR LF ]
+
+              The discussion below shows how the code for CLUMP is derived
+              from this regex.  Note that most of these concepts are from
+              property values of the Grapheme Cluster Boundary (GCB) property.
+              No code point can have multiple property values for a given
+              property.  Thus a code point in Prepend can't be in Control, but
+              it must be in !Control.  This is why Control above includes
+              GCB_Control plus CR plus LF.  The latter two are used in the GCB
+              property separately, and so can't be in GCB_Control, even though
+              they logically are controls.  Control is not the same as gc=cc,
+              but includes format and other characters as well.
+
+              The Unicode definition of Hangul-syllable is:
+                  L+
+                  | (L* ( ( V | LV ) V* | LVT ) T*)
+                  | T+ 
+                 )
+              Each of these is a value for the GCB property, and hence must be
+              disjoint, so the order they are tested is immaterial, so the
+              above can safely be changed to
+                  T+
+                  | L+
+                  | (L* ( LVT | ( V | LV ) V*) T*)
+
+              The last two terms can be combined like this:
+                  L* ( L
+                       | (( LVT | ( V | LV ) V*) T*))
+
+              And refactored into this:
+                  L* (L | LVT T* | V  V* T* | LV  V* T*)
+
+              That means that if we have seen any L's at all we can quit
+              there, but if the next character is a LVT, a V or and LV we
+              should keep going.
+
+              There is a subtlety with Prepend* which showed up in testing.
+              Note that the Begin, and only the Begin is required in:
+               | Prepend* Begin Extend*
+              Also, Begin contains '! Control'.  A Prepend must be a '!
+              Control', which means it must be a Begin.  What it comes down to
+              is that if we match Prepend* and then find no suitable Begin
+              afterwards, that if we backtrack the last Prepend, that one will
+              be a suitable Begin.
+           */
+
+           if (locinput >= PL_regeol)
                sayNO;
-           if (do_utf8) {
-               LOAD_UTF8_CHARCLASS_DIGIT();
-               if (OP(scan) == NDIGIT
-                   ? swash_fetch(PL_utf8_digit, (U8*)locinput, do_utf8)
-                   : isDIGIT_LC_utf8((U8*)locinput))
-               {
-                   sayNO;
+           if  (! utf8_target) {
+
+               /* Match either CR LF  or '.', as all the other possibilities
+                * require utf8 */
+               locinput++;         /* Match the . or CR */
+               if (nextchr == '\r'
+                   && locinput < PL_regeol
+                   && UCHARAT(locinput) == '\n') locinput++;
+           }
+           else {
+
+               /* Utf8: See if is ( CR LF ); already know that locinput <
+                * PL_regeol, so locinput+1 is in bounds */
+               if (nextchr == '\r' && UCHARAT(locinput + 1) == '\n') {
+                   locinput += 2;
                }
-               locinput += PL_utf8skip[nextchr];
-               nextchr = UCHARAT(locinput);
-               break;
+               else {
+                   /* In case have to backtrack to beginning, then match '.' */
+                   char *starting = locinput;
+
+                   /* In case have to backtrack the last prepend */
+                   char *previous_prepend = 0;
+
+                   LOAD_UTF8_CHARCLASS_GCB();
+
+                   /* Match (prepend)* */
+                   while (locinput < PL_regeol
+                          && swash_fetch(PL_utf8_X_prepend,
+                                         (U8*)locinput, utf8_target))
+                   {
+                       previous_prepend = locinput;
+                       locinput += UTF8SKIP(locinput);
+                   }
+
+                   /* As noted above, if we matched a prepend character, but
+                    * the next thing won't match, back off the last prepend we
+                    * matched, as it is guaranteed to match the begin */
+                   if (previous_prepend
+                       && (locinput >=  PL_regeol
+                           || ! swash_fetch(PL_utf8_X_begin,
+                                            (U8*)locinput, utf8_target)))
+                   {
+                       locinput = previous_prepend;
+                   }
+
+                   /* Note that here we know PL_regeol > locinput, as we
+                    * tested that upon input to this switch case, and if we
+                    * moved locinput forward, we tested the result just above
+                    * and it either passed, or we backed off so that it will
+                    * now pass */
+                   if (! swash_fetch(PL_utf8_X_begin, (U8*)locinput, utf8_target)) {
+
+                       /* Here did not match the required 'Begin' in the
+                        * second term.  So just match the very first
+                        * character, the '.' of the final term of the regex */
+                       locinput = starting + UTF8SKIP(starting);
+                   } else {
+
+                       /* Here is the beginning of a character that can have
+                        * an extender.  It is either a hangul syllable, or a
+                        * non-control */
+                       if (swash_fetch(PL_utf8_X_non_hangul,
+                                       (U8*)locinput, utf8_target))
+                       {
+
+                           /* Here not a Hangul syllable, must be a
+                            * ('!  * Control') */
+                           locinput += UTF8SKIP(locinput);
+                       } else {
+
+                           /* Here is a Hangul syllable.  It can be composed
+                            * of several individual characters.  One
+                            * possibility is T+ */
+                           if (swash_fetch(PL_utf8_X_T,
+                                           (U8*)locinput, utf8_target))
+                           {
+                               while (locinput < PL_regeol
+                                       && swash_fetch(PL_utf8_X_T,
+                                                       (U8*)locinput, utf8_target))
+                               {
+                                   locinput += UTF8SKIP(locinput);
+                               }
+                           } else {
+
+                               /* Here, not T+, but is a Hangul.  That means
+                                * it is one of the others: L, LV, LVT or V,
+                                * and matches:
+                                * L* (L | LVT T* | V  V* T* | LV  V* T*) */
+
+                               /* Match L*           */
+                               while (locinput < PL_regeol
+                                       && swash_fetch(PL_utf8_X_L,
+                                                       (U8*)locinput, utf8_target))
+                               {
+                                   locinput += UTF8SKIP(locinput);
+                               }
+
+                               /* Here, have exhausted L*.  If the next
+                                * character is not an LV, LVT nor V, it means
+                                * we had to have at least one L, so matches L+
+                                * in the original equation, we have a complete
+                                * hangul syllable.  Are done. */
+
+                               if (locinput < PL_regeol
+                                   && swash_fetch(PL_utf8_X_LV_LVT_V,
+                                                   (U8*)locinput, utf8_target))
+                               {
+
+                                   /* Otherwise keep going.  Must be LV, LVT
+                                    * or V.  See if LVT */
+                                   if (swash_fetch(PL_utf8_X_LVT,
+                                                   (U8*)locinput, utf8_target))
+                                   {
+                                       locinput += UTF8SKIP(locinput);
+                                   } else {
+
+                                       /* Must be  V or LV.  Take it, then
+                                        * match V*     */
+                                       locinput += UTF8SKIP(locinput);
+                                       while (locinput < PL_regeol
+                                               && swash_fetch(PL_utf8_X_V,
+                                                        (U8*)locinput, utf8_target))
+                                       {
+                                           locinput += UTF8SKIP(locinput);
+                                       }
+                                   }
+
+                                   /* And any of LV, LVT, or V can be followed
+                                    * by T*            */
+                                   while (locinput < PL_regeol
+                                          && swash_fetch(PL_utf8_X_T,
+                                                          (U8*)locinput,
+                                                          utf8_target))
+                                   {
+                                       locinput += UTF8SKIP(locinput);
+                                   }
+                               }
+                           }
+                       }
+
+                       /* Match any extender */
+                       while (locinput < PL_regeol
+                               && swash_fetch(PL_utf8_X_extend,
+                                               (U8*)locinput, utf8_target))
+                       {
+                           locinput += UTF8SKIP(locinput);
+                       }
+                   }
+               }
+               if (locinput > PL_regeol) sayNO;
            }
-           if (OP(scan) == NDIGIT
-               ? isDIGIT(nextchr) : isDIGIT_LC(nextchr))
-               sayNO;
-           nextchr = UCHARAT(++locinput);
-           break;
-       case CLUMP:
-           if (locinput >= PL_regeol)
-               sayNO;
-           if  (do_utf8) {
-               LOAD_UTF8_CHARCLASS_MARK();
-               if (swash_fetch(PL_utf8_mark,(U8*)locinput, do_utf8))
-                   sayNO;
-               locinput += PL_utf8skip[nextchr];
-               while (locinput < PL_regeol &&
-                      swash_fetch(PL_utf8_mark,(U8*)locinput, do_utf8))
-                   locinput += UTF8SKIP(locinput);
-               if (locinput > PL_regeol)
-                   sayNO;
-           } 
-           else
-              locinput++;
            nextchr = UCHARAT(locinput);
            break;
+            
+       case NREFFL:
+       {
+           char *s;
+           char type;
+           PL_reg_flags |= RF_tainted;
+           /* FALL THROUGH */
+       case NREF:
+       case NREFF:
+           type = OP(scan);
+           n = reg_check_named_buff_matched(rex,scan);
+
+            if ( n ) {
+                type = REF + ( type - NREF );
+                goto do_ref;
+            } else {
+                sayNO;
+            }
+            /* unreached */
        case REFFL:
            PL_reg_flags |= RF_tainted;
            /* FALL THROUGH */
         case REF:
-       case REFF: {
-           char *s;
+       case REFF: 
            n = ARG(scan);  /* which paren pair */
-           st->ln = PL_regstartp[n];
+           type = OP(scan);
+         do_ref:  
+           ln = PL_regoffs[n].start;
            PL_reg_leftiter = PL_reg_maxiter;           /* Void cache */
-           if ((I32)*PL_reglastparen < n || st->ln == -1)
+           if (*PL_reglastparen < n || ln == -1)
                sayNO;                  /* Do not match unless seen CLOSEn. */
-           if (st->ln == PL_regendp[n])
+           if (ln == PL_regoffs[n].end)
                break;
 
-           s = PL_bostr + st->ln;
-           if (do_utf8 && OP(scan) != REF) {   /* REF can do byte comparison */
+           s = PL_bostr + ln;
+           if (utf8_target && type != REF) {   /* REF can do byte comparison */
                char *l = locinput;
-               const char *e = PL_bostr + PL_regendp[n];
+               const char *e = PL_bostr + PL_regoffs[n].end;
                /*
                 * Note that we can't do the "other character" lookup trick as
                 * in the 8-bit case (no pun intended) because in Unicode we
                 * have to map both upper and title case to lower case.
                 */
-               if (OP(scan) == REFF) {
+               if (type == REFF) {
                    while (s < e) {
                        STRLEN ulen1, ulen2;
                        U8 tmpbuf1[UTF8_MAXBYTES_CASE+1];
@@ -3283,32 +3855,70 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
 
            /* Inline the first character, for speed. */
            if (UCHARAT(s) != nextchr &&
-               (OP(scan) == REF ||
-                (UCHARAT(s) != ((OP(scan) == REFF
-                                 ? PL_fold : PL_fold_locale)[nextchr]))))
+               (type == REF ||
+                (UCHARAT(s) != (type == REFF
+                                 ? PL_fold : PL_fold_locale)[nextchr])))
                sayNO;
-           st->ln = PL_regendp[n] - st->ln;
-           if (locinput + st->ln > PL_regeol)
+           ln = PL_regoffs[n].end - ln;
+           if (locinput + ln > PL_regeol)
                sayNO;
-           if (st->ln > 1 && (OP(scan) == REF
-                          ? memNE(s, locinput, st->ln)
-                          : (OP(scan) == REFF
-                             ? ibcmp(s, locinput, st->ln)
-                             : ibcmp_locale(s, locinput, st->ln))))
+           if (ln > 1 && (type == REF
+                          ? memNE(s, locinput, ln)
+                          : (type == REFF
+                             ? ! foldEQ(s, locinput, ln)
+                             : ! foldEQ_locale(s, locinput, ln))))
                sayNO;
-           locinput += st->ln;
+           locinput += ln;
            nextchr = UCHARAT(locinput);
            break;
-           }
-
+       }
        case NOTHING:
        case TAIL:
            break;
        case BACK:
            break;
-       case EVAL:
+
+#undef  ST
+#define ST st->u.eval
        {
            SV *ret;
+           REGEXP *re_sv;
+            regexp *re;
+            regexp_internal *rei;
+            regnode *startpoint;
+
+       case GOSTART:
+       case GOSUB: /*    /(...(?1))/   /(...(?&foo))/   */
+           if (cur_eval && cur_eval->locinput==locinput) {
+                if (cur_eval->u.eval.close_paren == (U32)ARG(scan)) 
+                    Perl_croak(aTHX_ "Infinite recursion in regex");
+                if ( ++nochange_depth > max_nochange_depth )
+                    Perl_croak(aTHX_ 
+                        "Pattern subroutine nesting without pos change"
+                        " exceeded limit in regex");
+            } else {
+                nochange_depth = 0;
+            }
+           re_sv = rex_sv;
+            re = rex;
+            rei = rexi;
+            (void)ReREFCNT_inc(rex_sv);
+            if (OP(scan)==GOSUB) {
+                startpoint = scan + ARG2L(scan);
+                ST.close_paren = ARG(scan);
+            } else {
+                startpoint = rei->program+1;
+                ST.close_paren = 0;
+            }
+            goto eval_recurse_doit;
+            /* NOTREACHED */
+        case EVAL:  /*   /(?{A})B/   /(??{A})B/  and /(?(?{A})X|Y)B/   */        
+            if (cur_eval && cur_eval->locinput==locinput) {
+               if ( ++nochange_depth > max_nochange_depth )
+                    Perl_croak(aTHX_ "EVAL without pos change exceeded limit in regex");
+            } else {
+                nochange_depth = 0;
+            }    
            {
                /* execute the code in the {...} */
                dSP;
@@ -3316,12 +3926,19 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                OP_4tree * const oop = PL_op;
                COP * const ocurcop = PL_curcop;
                PAD *old_comppad;
+               char *saved_regeol = PL_regeol;
            
                n = ARG(scan);
-               PL_op = (OP_4tree*)rex->data->data[n];
-               DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log, "  re_eval 0x%"UVxf"\n", PTR2UV(PL_op)) );
-               PAD_SAVE_LOCAL(old_comppad, (PAD*)rex->data->data[n + 2]);
-               PL_regendp[0] = PL_reg_magic->mg_len = locinput - PL_bostr;
+               PL_op = (OP_4tree*)rexi->data->data[n];
+               DEBUG_STATE_r( PerlIO_printf(Perl_debug_log, 
+                   "  re_eval 0x%"UVxf"\n", PTR2UV(PL_op)) );
+               PAD_SAVE_LOCAL(old_comppad, (PAD*)rexi->data->data[n + 2]);
+               PL_regoffs[0].end = PL_reg_magic->mg_len = locinput - PL_bostr;
+
+                if (sv_yes_mark) {
+                    SV *sv_mrk = get_sv("REGMARK", 1);
+                    sv_setsv(sv_mrk, sv_yes_mark);
+                }
 
                CALLRUNOPS(aTHX);                       /* Scalar context. */
                SPAGAIN;
@@ -3335,115 +3952,262 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                PL_op = oop;
                PAD_RESTORE_LOCAL(old_comppad);
                PL_curcop = ocurcop;
-               if (!st->logical) {
+               PL_regeol = saved_regeol;
+               if (!logical) {
                    /* /(?{...})/ */
                    sv_setsv(save_scalar(PL_replgv), ret);
                    break;
                }
            }
-           if (st->logical == 2) { /* Postponed subexpression: /(??{...})/ */
-               regexp *re;
+           if (logical == 2) { /* Postponed subexpression: /(??{...})/ */
+               logical = 0;
                {
                    /* extract RE object from returned value; compiling if
                     * necessary */
-
                    MAGIC *mg = NULL;
-                   SV *sv;
-                   if(SvROK(ret) && SvSMAGICAL(sv = SvRV(ret)))
-                       mg = mg_find(sv, PERL_MAGIC_qr);
-                   else if (SvSMAGICAL(ret)) {
-                       if (SvGMAGICAL(ret))
+                   REGEXP *rx = NULL;
+
+                   if (SvROK(ret)) {
+                       SV *const sv = SvRV(ret);
+
+                       if (SvTYPE(sv) == SVt_REGEXP) {
+                           rx = (REGEXP*) sv;
+                       } else if (SvSMAGICAL(sv)) {
+                           mg = mg_find(sv, PERL_MAGIC_qr);
+                           assert(mg);
+                       }
+                   } else if (SvTYPE(ret) == SVt_REGEXP) {
+                       rx = (REGEXP*) ret;
+                   } else if (SvSMAGICAL(ret)) {
+                       if (SvGMAGICAL(ret)) {
+                           /* I don't believe that there is ever qr magic
+                              here.  */
+                           assert(!mg_find(ret, PERL_MAGIC_qr));
                            sv_unmagic(ret, PERL_MAGIC_qr);
-                       else
+                       }
+                       else {
                            mg = mg_find(ret, PERL_MAGIC_qr);
+                           /* testing suggests mg only ends up non-NULL for
+                              scalars who were upgraded and compiled in the
+                              else block below. In turn, this is only
+                              triggered in the "postponed utf8 string" tests
+                              in t/op/pat.t  */
+                       }
                    }
 
                    if (mg) {
-                       re = (regexp *)mg->mg_obj;
-                       (void)ReREFCNT_inc(re);
+                       rx = (REGEXP *) mg->mg_obj; /*XXX:dmq*/
+                       assert(rx);
+                   }
+                   if (rx) {
+                       rx = reg_temp_copy(NULL, rx);
                    }
                    else {
-                       STRLEN len;
-                       const char * const t = SvPV_const(ret, len);
-                       PMOP pm;
+                       U32 pm_flags = 0;
                        const I32 osize = PL_regsize;
 
-                       Zero(&pm, 1, PMOP);
-                       if (DO_UTF8(ret)) pm.op_pmdynflags |= PMdf_DYN_UTF8;
-                       re = CALLREGCOMP(aTHX_ (char*)t, (char*)t + len, &pm);
+                       if (DO_UTF8(ret)) {
+                           assert (SvUTF8(ret));
+                       } else if (SvUTF8(ret)) {
+                           /* Not doing UTF-8, despite what the SV says. Is
+                              this only if we're trapped in use 'bytes'?  */
+                           /* Make a copy of the octet sequence, but without
+                              the flag on, as the compiler now honours the
+                              SvUTF8 flag on ret.  */
+                           STRLEN len;
+                           const char *const p = SvPV(ret, len);
+                           ret = newSVpvn_flags(p, len, SVs_TEMP);
+                       }
+                       rx = CALLREGCOMP(ret, pm_flags);
                        if (!(SvFLAGS(ret)
                              & (SVs_TEMP | SVs_PADTMP | SVf_READONLY
-                               | SVs_GMG)))
-                           sv_magic(ret,(SV*)ReREFCNT_inc(re),
-                                       PERL_MAGIC_qr,0,0);
+                                | SVs_GMG))) {
+                           /* This isn't a first class regexp. Instead, it's
+                              caching a regexp onto an existing, Perl visible
+                              scalar.  */
+                           sv_magic(ret, MUTABLE_SV(rx), PERL_MAGIC_qr, 0, 0);
+                       }
                        PL_regsize = osize;
                    }
+                   re_sv = rx;
+                   re = (struct regexp *)SvANY(rx);
                }
-
+                RXp_MATCH_COPIED_off(re);
+                re->subbeg = rex->subbeg;
+                re->sublen = rex->sublen;
+               rei = RXi_GET(re);
+                DEBUG_EXECUTE_r(
+                    debug_start_match(re_sv, utf8_target, locinput, PL_regeol,
+                        "Matching embedded");
+               );              
+               startpoint = rei->program + 1;
+                       ST.close_paren = 0; /* only used for GOSUB */
+                       /* borrowed from regtry */
+                if (PL_reg_start_tmpl <= re->nparens) {
+                    PL_reg_start_tmpl = re->nparens*3/2 + 3;
+                    if(PL_reg_start_tmp)
+                        Renew(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
+                    else
+                        Newx(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
+                }                      
+
+        eval_recurse_doit: /* Share code with GOSUB below this line */                         
                /* run the pattern returned from (??{...}) */
+               ST.cp = regcppush(0);   /* Save *all* the positions. */
+               REGCP_SET(ST.lastcp);
+               
+               PL_regoffs = re->offs; /* essentially NOOP on GOSUB */
+               
+               /* see regtry, specifically PL_reglast(?:close)?paren is a pointer! (i dont know why) :dmq */
+               PL_reglastparen = &re->lastparen;
+               PL_reglastcloseparen = &re->lastcloseparen;
+               re->lastparen = 0;
+               re->lastcloseparen = 0;
 
-               DEBUG_EXECUTE_r(
-                   PerlIO_printf(Perl_debug_log,
-                                 "Entering embedded \"%s%.60s%s%s\"\n",
-                                 PL_colors[0],
-                                 re->precomp,
-                                 PL_colors[1],
-                                 (strlen(re->precomp) > 60 ? "..." : ""))
-                   );
-
-               st->u.eval.cp = regcppush(0);   /* Save *all* the positions. */
-               REGCP_SET(st->u.eval.lastcp);
-               *PL_reglastparen = 0;
-               *PL_reglastcloseparen = 0;
                PL_reginput = locinput;
+               PL_regsize = 0;
 
                /* XXXX This is too dramatic a measure... */
                PL_reg_maxiter = 0;
 
-               st->logical = 0;
-               st->u.eval.toggleutf = ((PL_reg_flags & RF_utf8) != 0) ^
-                           ((re->reganch & ROPT_UTF8) != 0);
-               if (st->u.eval.toggleutf) PL_reg_flags ^= RF_utf8;
-               st->u.eval.prev_rex = rex;
-               rex = re;
-
-               /* resume to current state on success */
-               st->u.yes.prev_yes_state = yes_state;
-               yes_state = st;
-               PUSH_STATE(newst, resume_EVAL);
-               st = newst;
+               ST.toggle_reg_flags = PL_reg_flags;
+               if (RX_UTF8(re_sv))
+                   PL_reg_flags |= RF_utf8;
+               else
+                   PL_reg_flags &= ~RF_utf8;
+               ST.toggle_reg_flags ^= PL_reg_flags; /* diff of old and new */
 
-               /* now continue  from first node in postoned RE */
-               next = re->program + 1;
-               break;
+               ST.prev_rex = rex_sv;
+               ST.prev_curlyx = cur_curlyx;
+               SETREX(rex_sv,re_sv);
+               rex = re;
+               rexi = rei;
+               cur_curlyx = NULL;
+               ST.B = next;
+               ST.prev_eval = cur_eval;
+               cur_eval = st;
+               /* now continue from first node in postoned RE */
+               PUSH_YES_STATE_GOTO(EVAL_AB, startpoint);
                /* NOTREACHED */
            }
-           /* /(?(?{...})X|Y)/ */
-           st->sw = SvTRUE(ret);
-           st->logical = 0;
+           /* logical is 1,   /(?(?{...})X|Y)/ */
+           sw = cBOOL(SvTRUE(ret));
+           logical = 0;
            break;
        }
+
+       case EVAL_AB: /* cleanup after a successful (??{A})B */
+           /* note: this is called twice; first after popping B, then A */
+           PL_reg_flags ^= ST.toggle_reg_flags; 
+           ReREFCNT_dec(rex_sv);
+           SETREX(rex_sv,ST.prev_rex);
+           rex = (struct regexp *)SvANY(rex_sv);
+           rexi = RXi_GET(rex);
+           regcpblow(ST.cp);
+           cur_eval = ST.prev_eval;
+           cur_curlyx = ST.prev_curlyx;
+
+           /* rex was changed so update the pointer in PL_reglastparen and PL_reglastcloseparen */
+           PL_reglastparen = &rex->lastparen;
+           PL_reglastcloseparen = &rex->lastcloseparen;
+           /* also update PL_regoffs */
+           PL_regoffs = rex->offs;
+           
+           /* XXXX This is too dramatic a measure... */
+           PL_reg_maxiter = 0;
+            if ( nochange_depth )
+               nochange_depth--;
+           sayYES;
+
+
+       case EVAL_AB_fail: /* unsuccessfully ran A or B in (??{A})B */
+           /* note: this is called twice; first after popping B, then A */
+           PL_reg_flags ^= ST.toggle_reg_flags; 
+           ReREFCNT_dec(rex_sv);
+           SETREX(rex_sv,ST.prev_rex);
+           rex = (struct regexp *)SvANY(rex_sv);
+           rexi = RXi_GET(rex); 
+           /* rex was changed so update the pointer in PL_reglastparen and PL_reglastcloseparen */
+           PL_reglastparen = &rex->lastparen;
+           PL_reglastcloseparen = &rex->lastcloseparen;
+
+           PL_reginput = locinput;
+           REGCP_UNWIND(ST.lastcp);
+           regcppop(rex);
+           cur_eval = ST.prev_eval;
+           cur_curlyx = ST.prev_curlyx;
+           /* XXXX This is too dramatic a measure... */
+           PL_reg_maxiter = 0;
+           if ( nochange_depth )
+               nochange_depth--;
+           sayNO_SILENT;
+#undef ST
+
        case OPEN:
            n = ARG(scan);  /* which paren pair */
            PL_reg_start_tmp[n] = locinput;
            if (n > PL_regsize)
                PL_regsize = n;
+            lastopen = n;
            break;
        case CLOSE:
            n = ARG(scan);  /* which paren pair */
-           PL_regstartp[n] = PL_reg_start_tmp[n] - PL_bostr;
-           PL_regendp[n] = locinput - PL_bostr;
-           if (n > (I32)*PL_reglastparen)
+           PL_regoffs[n].start = PL_reg_start_tmp[n] - PL_bostr;
+           PL_regoffs[n].end = locinput - PL_bostr;
+           /*if (n > PL_regsize)
+               PL_regsize = n;*/
+           if (n > *PL_reglastparen)
                *PL_reglastparen = n;
            *PL_reglastcloseparen = n;
+            if (cur_eval && cur_eval->u.eval.close_paren == n) {
+               goto fake_end;
+           }    
            break;
+        case ACCEPT:
+            if (ARG(scan)){
+                regnode *cursor;
+                for (cursor=scan;
+                     cursor && OP(cursor)!=END; 
+                     cursor=regnext(cursor)) 
+                {
+                    if ( OP(cursor)==CLOSE ){
+                        n = ARG(cursor);
+                        if ( n <= lastopen ) {
+                            PL_regoffs[n].start
+                               = PL_reg_start_tmp[n] - PL_bostr;
+                            PL_regoffs[n].end = locinput - PL_bostr;
+                            /*if (n > PL_regsize)
+                            PL_regsize = n;*/
+                            if (n > *PL_reglastparen)
+                                *PL_reglastparen = n;
+                            *PL_reglastcloseparen = n;
+                            if ( n == ARG(scan) || (cur_eval &&
+                                cur_eval->u.eval.close_paren == n))
+                                break;
+                        }
+                    }
+                }
+            }
+           goto fake_end;
+           /*NOTREACHED*/          
        case GROUPP:
            n = ARG(scan);  /* which paren pair */
-           st->sw = ((I32)*PL_reglastparen >= n && PL_regendp[n] != -1);
+           sw = cBOOL(*PL_reglastparen >= n && PL_regoffs[n].end != -1);
+           break;
+       case NGROUPP:
+           /* reg_check_named_buff_matched returns 0 for no match */
+           sw = cBOOL(0 < reg_check_named_buff_matched(rex,scan));
            break;
+        case INSUBP:
+            n = ARG(scan);
+            sw = (cur_eval && (!n || cur_eval->u.eval.close_paren == n));
+            break;
+        case DEFINEP:
+            sw = 0;
+            break;
        case IFTHEN:
            PL_reg_leftiter = PL_reg_maxiter;           /* Void cache */
-           if (st->sw)
+           if (sw)
                next = NEXTOPER(NEXTOPER(scan));
            else {
                next = scan + ARG(scan);
@@ -3452,211 +4216,198 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
            }
            break;
        case LOGICAL:
-           st->logical = scan->flags;
+           logical = scan->flags;
            break;
+
 /*******************************************************************
- cc points to the regmatch_state associated with the most recent CURLYX.
- This struct contains info about the innermost (...)* loop (an
- "infoblock"), and a pointer to the next outer cc.
-
- Here is how Y(A)*Z is processed (if it is compiled into CURLYX/WHILEM):
-
-   1) After matching Y, regnode for CURLYX is processed;
-
-   2) This regnode populates cc, and calls regmatch() recursively
-      with the starting point at WHILEM node;
-
-   3) Each hit of WHILEM node tries to match A and Z (in the order
-      depending on the current iteration, min/max of {min,max} and
-      greediness).  The information about where are nodes for "A"
-      and "Z" is read from cc, as is info on how many times "A"
-      was already matched, and greediness.
-
-   4) After A matches, the same WHILEM node is hit again.
-
-   5) Each time WHILEM is hit, cc is the infoblock created by CURLYX
-      of the same pair.  Thus when WHILEM tries to match Z, it temporarily
-      resets cc, since this Y(A)*Z can be a part of some other loop:
-      as in (Y(A)*Z)*.  If Z matches, the automaton will hit the WHILEM node
-      of the external loop.
-
- Currently present infoblocks form a tree with a stem formed by st->cc
- and whatever it mentions via ->next, and additional attached trees
- corresponding to temporarily unset infoblocks as in "5" above.
-
- In the following picture, infoblocks for outer loop of
- (Y(A)*?Z)*?T are denoted O, for inner I.  NULL starting block
- is denoted by x.  The matched string is YAAZYAZT.  Temporarily postponed
- infoblocks are drawn below the "reset" infoblock.
-
- In fact in the picture below we do not show failed matches for Z and T
- by WHILEM blocks.  [We illustrate minimal matches, since for them it is
- more obvious *why* one needs to *temporary* unset infoblocks.]
-
-  Matched      REx position    InfoBlocks      Comment
-               (Y(A)*?Z)*?T    x
-               Y(A)*?Z)*?T     x <- O
-  Y            (A)*?Z)*?T      x <- O
-  Y            A)*?Z)*?T       x <- O <- I
-  YA           )*?Z)*?T        x <- O <- I
-  YA           A)*?Z)*?T       x <- O <- I
-  YAA          )*?Z)*?T        x <- O <- I
-  YAA          Z)*?T           x <- O          # Temporary unset I
-                                    I
-
-  YAAZ         Y(A)*?Z)*?T     x <- O
-                                    I
-
-  YAAZY                (A)*?Z)*?T      x <- O
-                                    I
-
-  YAAZY                A)*?Z)*?T       x <- O <- I
-                                    I
-
-  YAAZYA       )*?Z)*?T        x <- O <- I     
-                                    I
-
-  YAAZYA       Z)*?T           x <- O          # Temporary unset I
-                                    I,I
-
-  YAAZYAZ      )*?T            x <- O
-                                    I,I
-
-  YAAZYAZ      T               x               # Temporary unset O
-                               O
-                               I,I
-
-  YAAZYAZT                     x
-                               O
-                               I,I
- *******************************************************************/
-
-       case CURLYX: {
-               /* No need to save/restore up to this paren */
-               I32 parenfloor = scan->flags;
-
-               /* Dave says:
-                  
-                  CURLYX and WHILEM are always paired: they're the moral
-                  equivalent of pp_enteriter anbd pp_iter.
-
-                  The only time next could be null is if the node tree is
-                  corrupt. This was mentioned on p5p a few days ago.
-
-                  See http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-04/msg00556.html
-                  So we'll assert that this is true:
-               */
-               assert(next);
-               if (OP(PREVOPER(next)) == NOTHING) /* LONGJMP */
-                   next += ARG(next);
-               /* XXXX Probably it is better to teach regpush to support
-                  parenfloor > PL_regsize... */
-               if (parenfloor > (I32)*PL_reglastparen)
-                   parenfloor = *PL_reglastparen; /* Pessimization... */
-
-               st->u.curlyx.cp = PL_savestack_ix;
-               st->u.curlyx.outercc = st->cc;
-               st->cc = st;
-               /* these fields contain the state of the current curly.
-                * they are accessed by subsequent WHILEMs;
-                * cur and lastloc are also updated by WHILEM */
-               st->u.curlyx.parenfloor = parenfloor;
-               st->u.curlyx.cur = -1; /* this will be updated by WHILEM */
-               st->u.curlyx.min = ARG1(scan);
-               st->u.curlyx.max  = ARG2(scan);
-               st->u.curlyx.scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
-               st->u.curlyx.lastloc = 0;
-               /* st->next and st->minmod are also read by WHILEM */
 
-               PL_reginput = locinput;
-               REGMATCH(PREVOPER(next), CURLYX); /* start on the WHILEM */
-               /*** all unsaved local vars undefined at this point */
-               regcpblow(st->u.curlyx.cp);
-               st->cc = st->u.curlyx.outercc;
-               saySAME(result);
-           }
+The CURLYX/WHILEM pair of ops handle the most generic case of the /A*B/
+pattern, where A and B are subpatterns. (For simple A, CURLYM or
+STAR/PLUS/CURLY/CURLYN are used instead.)
+
+A*B is compiled as <CURLYX><A><WHILEM><B>
+
+On entry to the subpattern, CURLYX is called. This pushes a CURLYX
+state, which contains the current count, initialised to -1. It also sets
+cur_curlyx to point to this state, with any previous value saved in the
+state block.
+
+CURLYX then jumps straight to the WHILEM op, rather than executing A,
+since the pattern may possibly match zero times (i.e. it's a while {} loop
+rather than a do {} while loop).
+
+Each entry to WHILEM represents a successful match of A. The count in the
+CURLYX block is incremented, another WHILEM state is pushed, and execution
+passes to A or B depending on greediness and the current count.
+
+For example, if matching against the string a1a2a3b (where the aN are
+substrings that match /A/), then the match progresses as follows: (the
+pushed states are interspersed with the bits of strings matched so far):
+
+    <CURLYX cnt=-1>
+    <CURLYX cnt=0><WHILEM>
+    <CURLYX cnt=1><WHILEM> a1 <WHILEM>
+    <CURLYX cnt=2><WHILEM> a1 <WHILEM> a2 <WHILEM>
+    <CURLYX cnt=3><WHILEM> a1 <WHILEM> a2 <WHILEM> a3 <WHILEM>
+    <CURLYX cnt=3><WHILEM> a1 <WHILEM> a2 <WHILEM> a3 <WHILEM> b
+
+(Contrast this with something like CURLYM, which maintains only a single
+backtrack state:
+
+    <CURLYM cnt=0> a1
+    a1 <CURLYM cnt=1> a2
+    a1 a2 <CURLYM cnt=2> a3
+    a1 a2 a3 <CURLYM cnt=3> b
+)
+
+Each WHILEM state block marks a point to backtrack to upon partial failure
+of A or B, and also contains some minor state data related to that
+iteration.  The CURLYX block, pointed to by cur_curlyx, contains the
+overall state, such as the count, and pointers to the A and B ops.
+
+This is complicated slightly by nested CURLYX/WHILEM's. Since cur_curlyx
+must always point to the *current* CURLYX block, the rules are:
+
+When executing CURLYX, save the old cur_curlyx in the CURLYX state block,
+and set cur_curlyx to point the new block.
+
+When popping the CURLYX block after a successful or unsuccessful match,
+restore the previous cur_curlyx.
+
+When WHILEM is about to execute B, save the current cur_curlyx, and set it
+to the outer one saved in the CURLYX block.
+
+When popping the WHILEM block after a successful or unsuccessful B match,
+restore the previous cur_curlyx.
+
+Here's an example for the pattern (AI* BI)*BO
+I and O refer to inner and outer, C and W refer to CURLYX and WHILEM:
+
+cur_
+curlyx backtrack stack
+------ ---------------
+NULL   
+CO     <CO prev=NULL> <WO>
+CI     <CO prev=NULL> <WO> <CI prev=CO> <WI> ai 
+CO     <CO prev=NULL> <WO> <CI prev=CO> <WI> ai <WI prev=CI> bi 
+NULL   <CO prev=NULL> <WO> <CI prev=CO> <WI> ai <WI prev=CI> bi <WO prev=CO> bo
+
+At this point the pattern succeeds, and we work back down the stack to
+clean up, restoring as we go:
+
+CO     <CO prev=NULL> <WO> <CI prev=CO> <WI> ai <WI prev=CI> bi 
+CI     <CO prev=NULL> <WO> <CI prev=CO> <WI> ai 
+CO     <CO prev=NULL> <WO>
+NULL   
+
+*******************************************************************/
+
+#define ST st->u.curlyx
+
+       case CURLYX:    /* start of /A*B/  (for complex A) */
+       {
+           /* No need to save/restore up to this paren */
+           I32 parenfloor = scan->flags;
+           
+           assert(next); /* keep Coverity happy */
+           if (OP(PREVOPER(next)) == NOTHING) /* LONGJMP */
+               next += ARG(next);
+
+           /* XXXX Probably it is better to teach regpush to support
+              parenfloor > PL_regsize... */
+           if (parenfloor > (I32)*PL_reglastparen)
+               parenfloor = *PL_reglastparen; /* Pessimization... */
+
+           ST.prev_curlyx= cur_curlyx;
+           cur_curlyx = st;
+           ST.cp = PL_savestack_ix;
+
+           /* these fields contain the state of the current curly.
+            * they are accessed by subsequent WHILEMs */
+           ST.parenfloor = parenfloor;
+           ST.me = scan;
+           ST.B = next;
+           ST.minmod = minmod;
+           minmod = 0;
+           ST.count = -1;      /* this will be updated by WHILEM */
+           ST.lastloc = NULL;  /* this will be updated by WHILEM */
+
+           PL_reginput = locinput;
+           PUSH_YES_STATE_GOTO(CURLYX_end, PREVOPER(next));
            /* NOTREACHED */
-       case WHILEM: {
-               /*
-                * This is really hard to understand, because after we match
-                * what we're trying to match, we must make sure the rest of
-                * the REx is going to match for sure, and to do that we have
-                * to go back UP the parse tree by recursing ever deeper.  And
-                * if it fails, we have to reset our parent's current state
-                * that we can try again after backing off.
-                */
+       }
 
-               /* Dave says:
-
-                  st->cc gets initialised by CURLYX ready for use by WHILEM.
-                  So again, unless somethings been corrupted, st->cc cannot
-                  be null at that point in WHILEM.
-                  
-                  See http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-04/msg00556.html
-                  So we'll assert that this is true:
-               */
-               assert(st->cc);
-               st->u.whilem.lastloc = st->cc->u.curlyx.lastloc; /* Detection of 0-len. */
-               st->u.whilem.cache_offset = 0;
-               st->u.whilem.cache_bit = 0;
-               
-               n = st->cc->u.curlyx.cur + 1; /* how many we know we matched */
-               PL_reginput = locinput;
+       case CURLYX_end: /* just finished matching all of A*B */
+           cur_curlyx = ST.prev_curlyx;
+           sayYES;
+           /* NOTREACHED */
 
-               DEBUG_EXECUTE_r(
-                   PerlIO_printf(Perl_debug_log,
-                                 "%*s  %ld out of %ld..%ld  cc=%"UVxf"\n",
-                                 REPORT_CODE_OFF+PL_regindent*2, "",
-                                 (long)n, (long)st->cc->u.curlyx.min,
-                                 (long)st->cc->u.curlyx.max, PTR2UV(st->cc))
-                   );
+       case CURLYX_end_fail: /* just failed to match all of A*B */
+           regcpblow(ST.cp);
+           cur_curlyx = ST.prev_curlyx;
+           sayNO;
+           /* NOTREACHED */
 
-               /* If degenerate scan matches "", assume scan done. */
-
-               if (locinput == st->cc->u.curlyx.lastloc && n >= st->cc->u.curlyx.min) {
-                   st->u.whilem.savecc = st->cc;
-                   st->cc = st->cc->u.curlyx.outercc;
-                   if (st->cc)
-                       st->ln = st->cc->u.curlyx.cur;
-                   DEBUG_EXECUTE_r(
-                       PerlIO_printf(Perl_debug_log,
-                          "%*s  empty match detected, try continuation...\n",
-                          REPORT_CODE_OFF+PL_regindent*2, "")
-                       );
-                   REGMATCH(st->u.whilem.savecc->next, WHILEM1);
-                   /*** all unsaved local vars undefined at this point */
-                   st->cc = st->u.whilem.savecc;
-                   if (result)
-                       sayYES;
-                   if (st->cc->u.curlyx.outercc)
-                       st->cc->u.curlyx.outercc->u.curlyx.cur = st->ln;
-                   sayNO;
-               }
 
-               /* First just match a string of min scans. */
-
-               if (n < st->cc->u.curlyx.min) {
-                   st->cc->u.curlyx.cur = n;
-                   st->cc->u.curlyx.lastloc = locinput;
-                   REGMATCH(st->cc->u.curlyx.scan, WHILEM2);
-                   /*** all unsaved local vars undefined at this point */
-                   if (result)
-                       sayYES;
-                   st->cc->u.curlyx.cur = n - 1;
-                   st->cc->u.curlyx.lastloc = st->u.whilem.lastloc;
-                   sayNO;
-               }
+#undef ST
+#define ST st->u.whilem
+
+       case WHILEM:     /* just matched an A in /A*B/  (for complex A) */
+       {
+           /* see the discussion above about CURLYX/WHILEM */
+           I32 n;
+           int min = ARG1(cur_curlyx->u.curlyx.me);
+           int max = ARG2(cur_curlyx->u.curlyx.me);
+           regnode *A = NEXTOPER(cur_curlyx->u.curlyx.me) + EXTRA_STEP_2ARGS;
+
+           assert(cur_curlyx); /* keep Coverity happy */
+           n = ++cur_curlyx->u.curlyx.count; /* how many A's matched */
+           ST.save_lastloc = cur_curlyx->u.curlyx.lastloc;
+           ST.cache_offset = 0;
+           ST.cache_mask = 0;
+           
+           PL_reginput = locinput;
+
+           DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
+                 "%*s  whilem: matched %ld out of %d..%d\n",
+                 REPORT_CODE_OFF+depth*2, "", (long)n, min, max)
+           );
+
+           /* First just match a string of min A's. */
+
+           if (n < min) {
+               cur_curlyx->u.curlyx.lastloc = locinput;
+               PUSH_STATE_GOTO(WHILEM_A_pre, A);
+               /* NOTREACHED */
+           }
+
+           /* If degenerate A matches "", assume A done. */
+
+           if (locinput == cur_curlyx->u.curlyx.lastloc) {
+               DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
+                  "%*s  whilem: empty match detected, trying continuation...\n",
+                  REPORT_CODE_OFF+depth*2, "")
+               );
+               goto do_whilem_B_max;
+           }
+
+           /* super-linear cache processing */
+
+           if (scan->flags) {
 
-               if (scan->flags) {
-                   /* Check whether we already were at this position.
-                       Postpone detection until we know the match is not
-                       *that* much linear. */
                if (!PL_reg_maxiter) {
+                   /* start the countdown: Postpone detection until we
+                    * know the match is not *that* much linear. */
                    PL_reg_maxiter = (PL_regeol - PL_bostr + 1) * (scan->flags>>4);
+                   /* possible overflow for long strings and many CURLYX's */
+                   if (PL_reg_maxiter < 0)
+                       PL_reg_maxiter = I32_MAX;
                    PL_reg_leftiter = PL_reg_maxiter;
                }
+
                if (PL_reg_leftiter-- == 0) {
-                   const I32 size = (PL_reg_maxiter + 7 + POSCACHE_START)/8;
+                   /* initialise cache */
+                   const I32 size = (PL_reg_maxiter + 7)/8;
                    if (PL_reg_poscache) {
                        if ((I32)PL_reg_poscache_size < size) {
                            Renew(PL_reg_poscache, size, char);
@@ -3668,584 +4419,749 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                        PL_reg_poscache_size = size;
                        Newxz(PL_reg_poscache, size, char);
                    }
-                   DEBUG_EXECUTE_r(
-                       PerlIO_printf(Perl_debug_log,
-             "%sDetected a super-linear match, switching on caching%s...\n",
-                                     PL_colors[4], PL_colors[5])
-                       );
+                   DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
+      "%swhilem: Detected a super-linear match, switching on caching%s...\n",
+                             PL_colors[4], PL_colors[5])
+                   );
                }
+
                if (PL_reg_leftiter < 0) {
-                   st->u.whilem.cache_offset = locinput - PL_bostr;
-
-                   st->u.whilem.cache_offset = (scan->flags & 0xf) - 1 + POSCACHE_START
-                           + st->u.whilem.cache_offset * (scan->flags>>4);
-                   st->u.whilem.cache_bit = st->u.whilem.cache_offset % 8;
-                   st->u.whilem.cache_offset /= 8;
-                   if (PL_reg_poscache[st->u.whilem.cache_offset] & (1<<st->u.whilem.cache_bit)) {
-                   DEBUG_EXECUTE_r(
-                       PerlIO_printf(Perl_debug_log,
-                                     "%*s  already tried at this position...\n",
-                                     REPORT_CODE_OFF+PL_regindent*2, "")
+                   /* have we already failed at this position? */
+                   I32 offset, mask;
+                   offset  = (scan->flags & 0xf) - 1
+                               + (locinput - PL_bostr)  * (scan->flags>>4);
+                   mask    = 1 << (offset % 8);
+                   offset /= 8;
+                   if (PL_reg_poscache[offset] & mask) {
+                       DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
+                           "%*s  whilem: (cache) already tried at this position...\n",
+                           REPORT_CODE_OFF+depth*2, "")
                        );
-                       if (PL_reg_poscache[0] & (1<<POSCACHE_SUCCESS))
-                           /* cache records success */
-                           sayYES;
-                       else
-                           /* cache records failure */
-                           sayNO_SILENT;
+                       sayNO; /* cache records failure */
                    }
+                   ST.cache_offset = offset;
+                   ST.cache_mask   = mask;
                }
-               }
+           }
 
-               /* Prefer next over scan for minimal matching. */
-
-               if (st->cc->minmod) {
-                   st->u.whilem.savecc = st->cc;
-                   st->cc = st->cc->u.curlyx.outercc;
-                   if (st->cc)
-                       st->ln = st->cc->u.curlyx.cur;
-                   st->u.whilem.cp = regcppush(st->u.whilem.savecc->u.curlyx.parenfloor);
-                   REGCP_SET(st->u.whilem.lastcp);
-                   REGMATCH(st->u.whilem.savecc->next, WHILEM3);
-                   /*** all unsaved local vars undefined at this point */
-                   st->cc = st->u.whilem.savecc;
-                   if (result) {
-                       regcpblow(st->u.whilem.cp);
-                       CACHEsayYES;    /* All done. */
-                   }
-                   REGCP_UNWIND(st->u.whilem.lastcp);
-                   regcppop(rex);
-                   if (st->cc->u.curlyx.outercc)
-                       st->cc->u.curlyx.outercc->u.curlyx.cur = st->ln;
-
-                   if (n >= st->cc->u.curlyx.max) { /* Maximum greed exceeded? */
-                       if (ckWARN(WARN_REGEXP) && n >= REG_INFTY
-                           && !(PL_reg_flags & RF_warned)) {
-                           PL_reg_flags |= RF_warned;
-                           Perl_warner(aTHX_ packWARN(WARN_REGEXP), "%s limit (%d) exceeded",
-                                "Complex regular subexpression recursion",
-                                REG_INFTY - 1);
-                       }
-                       CACHEsayNO;
-                   }
+           /* Prefer B over A for minimal matching. */
 
-                   DEBUG_EXECUTE_r(
-                       PerlIO_printf(Perl_debug_log,
-                                     "%*s  trying longer...\n",
-                                     REPORT_CODE_OFF+PL_regindent*2, "")
-                       );
-                   /* Try scanning more and see if it helps. */
-                   PL_reginput = locinput;
-                   st->cc->u.curlyx.cur = n;
-                   st->cc->u.curlyx.lastloc = locinput;
-                   st->u.whilem.cp = regcppush(st->cc->u.curlyx.parenfloor);
-                   REGCP_SET(st->u.whilem.lastcp);
-                   REGMATCH(st->cc->u.curlyx.scan, WHILEM4);
-                   /*** all unsaved local vars undefined at this point */
-                   if (result) {
-                       regcpblow(st->u.whilem.cp);
-                       CACHEsayYES;
-                   }
-                   REGCP_UNWIND(st->u.whilem.lastcp);
-                   regcppop(rex);
-                   st->cc->u.curlyx.cur = n - 1;
-                   st->cc->u.curlyx.lastloc = st->u.whilem.lastloc;
-                   CACHEsayNO;
-               }
+           if (cur_curlyx->u.curlyx.minmod) {
+               ST.save_curlyx = cur_curlyx;
+               cur_curlyx = cur_curlyx->u.curlyx.prev_curlyx;
+               ST.cp = regcppush(ST.save_curlyx->u.curlyx.parenfloor);
+               REGCP_SET(ST.lastcp);
+               PUSH_YES_STATE_GOTO(WHILEM_B_min, ST.save_curlyx->u.curlyx.B);
+               /* NOTREACHED */
+           }
 
-               /* Prefer scan over next for maximal matching. */
-
-               if (n < st->cc->u.curlyx.max) { /* More greed allowed? */
-                   st->u.whilem.cp = regcppush(st->cc->u.curlyx.parenfloor);
-                   st->cc->u.curlyx.cur = n;
-                   st->cc->u.curlyx.lastloc = locinput;
-                   REGCP_SET(st->u.whilem.lastcp);
-                   REGMATCH(st->cc->u.curlyx.scan, WHILEM5);
-                   /*** all unsaved local vars undefined at this point */
-                   if (result) {
-                       regcpblow(st->u.whilem.cp);
-                       CACHEsayYES;
-                   }
-                   REGCP_UNWIND(st->u.whilem.lastcp);
-                   regcppop(rex);      /* Restore some previous $<digit>s? */
-                   PL_reginput = locinput;
-                   DEBUG_EXECUTE_r(
-                       PerlIO_printf(Perl_debug_log,
-                                     "%*s  failed, try continuation...\n",
-                                     REPORT_CODE_OFF+PL_regindent*2, "")
-                       );
-               }
-               if (ckWARN(WARN_REGEXP) && n >= REG_INFTY
-                       && !(PL_reg_flags & RF_warned)) {
+           /* Prefer A over B for maximal matching. */
+
+           if (n < max) { /* More greed allowed? */
+               ST.cp = regcppush(cur_curlyx->u.curlyx.parenfloor);
+               cur_curlyx->u.curlyx.lastloc = locinput;
+               REGCP_SET(ST.lastcp);
+               PUSH_STATE_GOTO(WHILEM_A_max, A);
+               /* NOTREACHED */
+           }
+           goto do_whilem_B_max;
+       }
+       /* NOTREACHED */
+
+       case WHILEM_B_min: /* just matched B in a minimal match */
+       case WHILEM_B_max: /* just matched B in a maximal match */
+           cur_curlyx = ST.save_curlyx;
+           sayYES;
+           /* NOTREACHED */
+
+       case WHILEM_B_max_fail: /* just failed to match B in a maximal match */
+           cur_curlyx = ST.save_curlyx;
+           cur_curlyx->u.curlyx.lastloc = ST.save_lastloc;
+           cur_curlyx->u.curlyx.count--;
+           CACHEsayNO;
+           /* NOTREACHED */
+
+       case WHILEM_A_min_fail: /* just failed to match A in a minimal match */
+           REGCP_UNWIND(ST.lastcp);
+           regcppop(rex);
+           /* FALL THROUGH */
+       case WHILEM_A_pre_fail: /* just failed to match even minimal A */
+           cur_curlyx->u.curlyx.lastloc = ST.save_lastloc;
+           cur_curlyx->u.curlyx.count--;
+           CACHEsayNO;
+           /* NOTREACHED */
+
+       case WHILEM_A_max_fail: /* just failed to match A in a maximal match */
+           REGCP_UNWIND(ST.lastcp);
+           regcppop(rex);      /* Restore some previous $<digit>s? */
+           PL_reginput = locinput;
+           DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
+               "%*s  whilem: failed, trying continuation...\n",
+               REPORT_CODE_OFF+depth*2, "")
+           );
+         do_whilem_B_max:
+           if (cur_curlyx->u.curlyx.count >= REG_INFTY
+               && ckWARN(WARN_REGEXP)
+               && !(PL_reg_flags & RF_warned))
+           {
+               PL_reg_flags |= RF_warned;
+               Perl_warner(aTHX_ packWARN(WARN_REGEXP), "%s limit (%d) exceeded",
+                    "Complex regular subexpression recursion",
+                    REG_INFTY - 1);
+           }
+
+           /* now try B */
+           ST.save_curlyx = cur_curlyx;
+           cur_curlyx = cur_curlyx->u.curlyx.prev_curlyx;
+           PUSH_YES_STATE_GOTO(WHILEM_B_max, ST.save_curlyx->u.curlyx.B);
+           /* NOTREACHED */
+
+       case WHILEM_B_min_fail: /* just failed to match B in a minimal match */
+           cur_curlyx = ST.save_curlyx;
+           REGCP_UNWIND(ST.lastcp);
+           regcppop(rex);
+
+           if (cur_curlyx->u.curlyx.count >= /*max*/ARG2(cur_curlyx->u.curlyx.me)) {
+               /* Maximum greed exceeded */
+               if (cur_curlyx->u.curlyx.count >= REG_INFTY
+                   && ckWARN(WARN_REGEXP)
+                   && !(PL_reg_flags & RF_warned))
+               {
                    PL_reg_flags |= RF_warned;
-                   Perl_warner(aTHX_ packWARN(WARN_REGEXP), "%s limit (%d) exceeded",
-                        "Complex regular subexpression recursion",
-                        REG_INFTY - 1);
+                   Perl_warner(aTHX_ packWARN(WARN_REGEXP),
+                       "%s limit (%d) exceeded",
+                       "Complex regular subexpression recursion",
+                       REG_INFTY - 1);
                }
-
-               /* Failed deeper matches of scan, so see if this one works. */
-               st->u.whilem.savecc = st->cc;
-               st->cc = st->cc->u.curlyx.outercc;
-               if (st->cc)
-                   st->ln = st->cc->u.curlyx.cur;
-               REGMATCH(st->u.whilem.savecc->next, WHILEM6);
-               /*** all unsaved local vars undefined at this point */
-               st->cc = st->u.whilem.savecc;
-               if (result)
-                   CACHEsayYES;
-               if (st->cc->u.curlyx.outercc)
-                   st->cc->u.curlyx.outercc->u.curlyx.cur = st->ln;
-               st->cc->u.curlyx.cur = n - 1;
-               st->cc->u.curlyx.lastloc = st->u.whilem.lastloc;
+               cur_curlyx->u.curlyx.count--;
                CACHEsayNO;
            }
+
+           DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
+               "%*s  trying longer...\n", REPORT_CODE_OFF+depth*2, "")
+           );
+           /* Try grabbing another A and see if it helps. */
+           PL_reginput = locinput;
+           cur_curlyx->u.curlyx.lastloc = locinput;
+           ST.cp = regcppush(cur_curlyx->u.curlyx.parenfloor);
+           REGCP_SET(ST.lastcp);
+           PUSH_STATE_GOTO(WHILEM_A_min,
+               /*A*/ NEXTOPER(ST.save_curlyx->u.curlyx.me) + EXTRA_STEP_2ARGS);
            /* NOTREACHED */
-       case BRANCHJ:
+
+#undef  ST
+#define ST st->u.branch
+
+       case BRANCHJ:       /*  /(...|A|...)/ with long next pointer */
            next = scan + ARG(scan);
            if (next == scan)
                next = NULL;
-           inner = NEXTOPER(NEXTOPER(scan));
-           goto do_branch;
-       case BRANCH:
-           inner = NEXTOPER(scan);
-         do_branch:
-           {
-               I32 type;
-               type = OP(scan);
-               if (!next || OP(next) != type)  /* No choice. */
-                   next = inner;       /* Avoid recursion. */
-               else {
-                   const I32 lastparen = *PL_reglastparen;
-                   /* Put unwinding data on stack */
-                   const I32 unwind1 = SSNEWt(1,re_unwind_branch_t);
-                   re_unwind_branch_t * const uw = SSPTRt(unwind1,re_unwind_branch_t);
-
-                   uw->prev = st->unwind;
-                   st->unwind = unwind1;
-                   uw->type = ((type == BRANCH)
-                               ? RE_UNWIND_BRANCH
-                               : RE_UNWIND_BRANCHJ);
-                   uw->lastparen = lastparen;
-                   uw->next = next;
-                   uw->locinput = locinput;
-                   uw->nextchr = nextchr;
-                   uw->minmod = st->minmod;
-#ifdef DEBUGGING
-                   uw->regindent = ++PL_regindent;
-#endif
+           scan = NEXTOPER(scan);
+           /* FALL THROUGH */
 
-                   REGCP_SET(uw->lastcp);
+       case BRANCH:        /*  /(...|A|...)/ */
+           scan = NEXTOPER(scan); /* scan now points to inner node */
+           ST.lastparen = *PL_reglastparen;
+           ST.next_branch = next;
+           REGCP_SET(ST.cp);
+           PL_reginput = locinput;
 
-                   /* Now go into the first branch */
-                   next = inner;
-               }
+           /* Now go into the branch */
+           if (has_cutgroup) {
+               PUSH_YES_STATE_GOTO(BRANCH_next, scan);    
+           } else {
+               PUSH_STATE_GOTO(BRANCH_next, scan);
            }
-           break;
+           /* NOTREACHED */
+        case CUTGROUP:
+            PL_reginput = locinput;
+            sv_yes_mark = st->u.mark.mark_name = scan->flags ? NULL :
+                MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
+            PUSH_STATE_GOTO(CUTGROUP_next,next);
+            /* NOTREACHED */
+        case CUTGROUP_next_fail:
+            do_cutgroup = 1;
+            no_final = 1;
+            if (st->u.mark.mark_name)
+                sv_commit = st->u.mark.mark_name;
+            sayNO;         
+            /* NOTREACHED */
+        case BRANCH_next:
+            sayYES;
+            /* NOTREACHED */
+       case BRANCH_next_fail: /* that branch failed; try the next, if any */
+           if (do_cutgroup) {
+               do_cutgroup = 0;
+               no_final = 0;
+           }
+           REGCP_UNWIND(ST.cp);
+           for (n = *PL_reglastparen; n > ST.lastparen; n--)
+               PL_regoffs[n].end = -1;
+           *PL_reglastparen = n;
+           /*dmq: *PL_reglastcloseparen = n; */
+           scan = ST.next_branch;
+           /* no more branches? */
+           if (!scan || (OP(scan) != BRANCH && OP(scan) != BRANCHJ)) {
+               DEBUG_EXECUTE_r({
+                   PerlIO_printf( Perl_debug_log,
+                       "%*s  %sBRANCH failed...%s\n",
+                       REPORT_CODE_OFF+depth*2, "", 
+                       PL_colors[4],
+                       PL_colors[5] );
+               });
+               sayNO_SILENT;
+            }
+           continue; /* execute next BRANCH[J] op */
+           /* NOTREACHED */
+    
        case MINMOD:
-           st->minmod = 1;
+           minmod = 1;
            break;
-       case CURLYM:
-       {
-           st->u.curlym.l = st->u.curlym.matches = 0;
-       
-           /* We suppose that the next guy does not need
-              backtracking: in particular, it is of constant non-zero length,
-              and has no parenths to influence future backrefs. */
-           st->ln = ARG1(scan);  /* min to match */
-           n  = ARG2(scan);  /* max to match */
-           st->u.curlym.paren = scan->flags;
-           if (st->u.curlym.paren) {
-               if (st->u.curlym.paren > PL_regsize)
-                   PL_regsize = st->u.curlym.paren;
-               if (st->u.curlym.paren > (I32)*PL_reglastparen)
-                   *PL_reglastparen = st->u.curlym.paren;
-           }
+
+#undef  ST
+#define ST st->u.curlym
+
+       case CURLYM:    /* /A{m,n}B/ where A is fixed-length */
+
+           /* This is an optimisation of CURLYX that enables us to push
+            * only a single backtracking state, no matter how many matches
+            * there are in {m,n}. It relies on the pattern being constant
+            * length, with no parens to influence future backrefs
+            */
+
+           ST.me = scan;
            scan = NEXTOPER(scan) + NODE_STEP_REGNODE;
-           if (st->u.curlym.paren)
+
+           /* if paren positive, emulate an OPEN/CLOSE around A */
+           if (ST.me->flags) {
+               U32 paren = ST.me->flags;
+               if (paren > PL_regsize)
+                   PL_regsize = paren;
+               if (paren > *PL_reglastparen)
+                   *PL_reglastparen = paren;
                scan += NEXT_OFF(scan); /* Skip former OPEN. */
+           }
+           ST.A = scan;
+           ST.B = next;
+           ST.alen = 0;
+           ST.count = 0;
+           ST.minmod = minmod;
+           minmod = 0;
+           ST.c1 = CHRTEST_UNINIT;
+           REGCP_SET(ST.cp);
+
+           if (!(ST.minmod ? ARG1(ST.me) : ARG2(ST.me))) /* min/max */
+               goto curlym_do_B;
+
+         curlym_do_A: /* execute the A in /A{m,n}B/  */
            PL_reginput = locinput;
-           st->u.curlym.maxwanted = st->minmod ? st->ln : n;
-           while (PL_reginput < PL_regeol && st->u.curlym.matches < st->u.curlym.maxwanted) {
-               /* resume to current state on success */
-               st->u.yes.prev_yes_state = yes_state;
-               yes_state = st;
-               REGMATCH(scan, CURLYM1);
-               yes_state = st->u.yes.prev_yes_state;
-               /*** all unsaved local vars undefined at this point */
-               if (!result)
-                   break;
-               /* on first match, determine length, u.curlym.l */
-               if (!st->u.curlym.matches++) {
-                   if (PL_reg_match_utf8) {
-                       char *s = locinput;
-                       while (s < PL_reginput) {
-                           st->u.curlym.l++;
-                           s += UTF8SKIP(s);
-                       }
-                   }
-                   else {
-                       st->u.curlym.l = PL_reginput - locinput;
-                   }
-                   if (st->u.curlym.l == 0) {
-                       st->u.curlym.matches = st->u.curlym.maxwanted;
-                       break;
+           PUSH_YES_STATE_GOTO(CURLYM_A, ST.A); /* match A */
+           /* NOTREACHED */
+
+       case CURLYM_A: /* we've just matched an A */
+           locinput = st->locinput;
+           nextchr = UCHARAT(locinput);
+
+           ST.count++;
+           /* after first match, determine A's length: u.curlym.alen */
+           if (ST.count == 1) {
+               if (PL_reg_match_utf8) {
+                   char *s = locinput;
+                   while (s < PL_reginput) {
+                       ST.alen++;
+                       s += UTF8SKIP(s);
                    }
                }
-               locinput = PL_reginput;
-           }
-
-           PL_reginput = locinput;
-           if (st->u.curlym.matches < st->ln) {
-               st->minmod = 0;
-               sayNO;
+               else {
+                   ST.alen = PL_reginput - locinput;
+               }
+               if (ST.alen == 0)
+                   ST.count = ST.minmod ? ARG1(ST.me) : ARG2(ST.me);
            }
-
            DEBUG_EXECUTE_r(
                PerlIO_printf(Perl_debug_log,
-                         "%*s  matched %"IVdf" times, len=%"IVdf"...\n",
-                         (int)(REPORT_CODE_OFF+PL_regindent*2), "",
-                         (IV) st->u.curlym.matches, (IV)st->u.curlym.l)
+                         "%*s  CURLYM now matched %"IVdf" times, len=%"IVdf"...\n",
+                         (int)(REPORT_CODE_OFF+(depth*2)), "",
+                         (IV) ST.count, (IV)ST.alen)
            );
 
-           /* calculate c1 and c1 for possible match of 1st char
-            * following curly */
-           st->u.curlym.c1 = st->u.curlym.c2 = CHRTEST_VOID;
-           if (HAS_TEXT(next) || JUMPABLE(next)) {
-               regnode *text_node = next;
-               if (! HAS_TEXT(text_node)) FIND_NEXT_IMPT(text_node);
-               if (HAS_TEXT(text_node)
-                   && PL_regkind[(U8)OP(text_node)] != REF)
-               {
-                   st->u.curlym.c1 = (U8)*STRING(text_node);
-                   st->u.curlym.c2 =
-                       (OP(text_node) == EXACTF || OP(text_node) == REFF)
-                       ? PL_fold[st->u.curlym.c1]
-                       : (OP(text_node) == EXACTFL || OP(text_node) == REFFL)
-                           ? PL_fold_locale[st->u.curlym.c1]
-                           : st->u.curlym.c1;
-               }
+           locinput = PL_reginput;
+                       
+           if (cur_eval && cur_eval->u.eval.close_paren && 
+               cur_eval->u.eval.close_paren == (U32)ST.me->flags) 
+               goto fake_end;
+               
+           {
+               I32 max = (ST.minmod ? ARG1(ST.me) : ARG2(ST.me));
+               if ( max == REG_INFTY || ST.count < max )
+                   goto curlym_do_A; /* try to match another A */
            }
+           goto curlym_do_B; /* try to match B */
 
-           REGCP_SET(st->u.curlym.lastcp);
+       case CURLYM_A_fail: /* just failed to match an A */
+           REGCP_UNWIND(ST.cp);
 
-           st->u.curlym.minmod = st->minmod;
-           st->minmod = 0;
-           while (st->u.curlym.matches >= st->ln
-               && (st->u.curlym.matches <= n
-                   /* for REG_INFTY, ln could overflow to negative */
-                   || (n == REG_INFTY && st->u.curlym.matches >= 0)))
-           { 
-               /* If it could work, try it. */
-               if (st->u.curlym.c1 == CHRTEST_VOID ||
-                   UCHARAT(PL_reginput) == st->u.curlym.c1 ||
-                   UCHARAT(PL_reginput) == st->u.curlym.c2)
-               {
-                   DEBUG_EXECUTE_r(
-                       PerlIO_printf(Perl_debug_log,
-                           "%*s  trying tail with matches=%"IVdf"...\n",
-                           (int)(REPORT_CODE_OFF+PL_regindent*2),
-                           "", (IV)st->u.curlym.matches)
-                       );
-                   if (st->u.curlym.paren) {
-                       if (st->u.curlym.matches) {
-                           PL_regstartp[st->u.curlym.paren]
-                               = HOPc(PL_reginput, -st->u.curlym.l) - PL_bostr;
-                           PL_regendp[st->u.curlym.paren] = PL_reginput - PL_bostr;
-                       }
-                       else
-                           PL_regendp[st->u.curlym.paren] = -1;
-                   }
-                   /* resume to current state on success */
-                   st->u.yes.prev_yes_state = yes_state;
-                   yes_state = st;
-                   REGMATCH(next, CURLYM2);
-                   yes_state = st->u.yes.prev_yes_state;
-                   /*** all unsaved local vars undefined at this point */
-                   if (result)
-                       /* XXX tmp sayYES; */
-                       sayYES_FINAL;
-                   REGCP_UNWIND(st->u.curlym.lastcp);
-               }
-               /* Couldn't or didn't -- move forward/backward. */
-               if (st->u.curlym.minmod) {
-                   PL_reginput = locinput;
-                   /* resume to current state on success */
-                   st->u.yes.prev_yes_state = yes_state;
-                   yes_state = st;
-                   REGMATCH(scan, CURLYM3);
-                   yes_state = st->u.yes.prev_yes_state;
-                   /*** all unsaved local vars undefined at this point */
-                   if (result) {
-                       st->u.curlym.matches++;
-                       locinput = PL_reginput;
+           if (ST.minmod || ST.count < ARG1(ST.me) /* min*/ 
+               || (cur_eval && cur_eval->u.eval.close_paren &&
+                   cur_eval->u.eval.close_paren == (U32)ST.me->flags))
+               sayNO;
+
+         curlym_do_B: /* execute the B in /A{m,n}B/  */
+           PL_reginput = locinput;
+           if (ST.c1 == CHRTEST_UNINIT) {
+               /* calculate c1 and c2 for possible match of 1st char
+                * following curly */
+               ST.c1 = ST.c2 = CHRTEST_VOID;
+               if (HAS_TEXT(ST.B) || JUMPABLE(ST.B)) {
+                   regnode *text_node = ST.B;
+                   if (! HAS_TEXT(text_node))
+                       FIND_NEXT_IMPT(text_node);
+                   /* this used to be 
+                       
+                       (HAS_TEXT(text_node) && PL_regkind[OP(text_node)] == EXACT)
+                       
+                       But the former is redundant in light of the latter.
+                       
+                       if this changes back then the macro for 
+                       IS_TEXT and friends need to change.
+                    */
+                   if (PL_regkind[OP(text_node)] == EXACT)
+                   {
+                       
+                       ST.c1 = (U8)*STRING(text_node);
+                       ST.c2 =
+                           (IS_TEXTF(text_node))
+                           ? PL_fold[ST.c1]
+                           : (IS_TEXTFL(text_node))
+                               ? PL_fold_locale[ST.c1]
+                               : ST.c1;
                    }
-                   else
-                       sayNO;
                }
-               else {
-                   st->u.curlym.matches--;
-                   locinput = HOPc(locinput, -st->u.curlym.l);
-                   PL_reginput = locinput;
+           }
+
+           DEBUG_EXECUTE_r(
+               PerlIO_printf(Perl_debug_log,
+                   "%*s  CURLYM trying tail with matches=%"IVdf"...\n",
+                   (int)(REPORT_CODE_OFF+(depth*2)),
+                   "", (IV)ST.count)
+               );
+           if (ST.c1 != CHRTEST_VOID
+                   && UCHARAT(PL_reginput) != ST.c1
+                   && UCHARAT(PL_reginput) != ST.c2)
+           {
+               /* simulate B failing */
+               DEBUG_OPTIMISE_r(
+                   PerlIO_printf(Perl_debug_log,
+                       "%*s  CURLYM Fast bail c1=%"IVdf" c2=%"IVdf"\n",
+                       (int)(REPORT_CODE_OFF+(depth*2)),"",
+                       (IV)ST.c1,(IV)ST.c2
+               ));
+               state_num = CURLYM_B_fail;
+               goto reenter_switch;
+           }
+
+           if (ST.me->flags) {
+               /* mark current A as captured */
+               I32 paren = ST.me->flags;
+               if (ST.count) {
+                   PL_regoffs[paren].start
+                       = HOPc(PL_reginput, -ST.alen) - PL_bostr;
+                   PL_regoffs[paren].end = PL_reginput - PL_bostr;
+                   /*dmq: *PL_reglastcloseparen = paren; */
                }
+               else
+                   PL_regoffs[paren].end = -1;
+               if (cur_eval && cur_eval->u.eval.close_paren &&
+                   cur_eval->u.eval.close_paren == (U32)ST.me->flags) 
+               {
+                   if (ST.count) 
+                       goto fake_end;
+                   else
+                       sayNO;
+               }
            }
-           sayNO;
+           
+           PUSH_STATE_GOTO(CURLYM_B, ST.B); /* match B */
            /* NOTREACHED */
-           break;
-       }
-       case CURLYN:
-           st->u.plus.paren = scan->flags;     /* Which paren to set */
-           if (st->u.plus.paren > PL_regsize)
-               PL_regsize = st->u.plus.paren;
-           if (st->u.plus.paren > (I32)*PL_reglastparen)
-               *PL_reglastparen = st->u.plus.paren;
-           st->ln = ARG1(scan);  /* min to match */
-           n  = ARG2(scan);  /* max to match */
-            scan = regnext(NEXTOPER(scan) + NODE_STEP_REGNODE);
-           goto repeat;
-       case CURLY:
-           st->u.plus.paren = 0;
-           st->ln = ARG1(scan);  /* min to match */
-           n  = ARG2(scan);  /* max to match */
-           scan = NEXTOPER(scan) + NODE_STEP_REGNODE;
-           goto repeat;
-       case STAR:
-           st->ln = 0;
-           n = REG_INFTY;
+
+       case CURLYM_B_fail: /* just failed to match a B */
+           REGCP_UNWIND(ST.cp);
+           if (ST.minmod) {
+               I32 max = ARG2(ST.me);
+               if (max != REG_INFTY && ST.count == max)
+                   sayNO;
+               goto curlym_do_A; /* try to match a further A */
+           }
+           /* backtrack one A */
+           if (ST.count == ARG1(ST.me) /* min */)
+               sayNO;
+           ST.count--;
+           locinput = HOPc(locinput, -ST.alen);
+           goto curlym_do_B; /* try to match B */
+
+#undef ST
+#define ST st->u.curly
+
+#define CURLY_SETPAREN(paren, success) \
+    if (paren) { \
+       if (success) { \
+           PL_regoffs[paren].start = HOPc(locinput, -1) - PL_bostr; \
+           PL_regoffs[paren].end = locinput - PL_bostr; \
+           *PL_reglastcloseparen = paren; \
+       } \
+       else \
+           PL_regoffs[paren].end = -1; \
+    }
+
+       case STAR:              /*  /A*B/ where A is width 1 */
+           ST.paren = 0;
+           ST.min = 0;
+           ST.max = REG_INFTY;
            scan = NEXTOPER(scan);
-           st->u.plus.paren = 0;
            goto repeat;
-       case PLUS:
-           st->ln = 1;
-           n = REG_INFTY;
+       case PLUS:              /*  /A+B/ where A is width 1 */
+           ST.paren = 0;
+           ST.min = 1;
+           ST.max = REG_INFTY;
            scan = NEXTOPER(scan);
-           st->u.plus.paren = 0;
+           goto repeat;
+       case CURLYN:            /*  /(A){m,n}B/ where A is width 1 */
+           ST.paren = scan->flags;     /* Which paren to set */
+           if (ST.paren > PL_regsize)
+               PL_regsize = ST.paren;
+           if (ST.paren > *PL_reglastparen)
+               *PL_reglastparen = ST.paren;
+           ST.min = ARG1(scan);  /* min to match */
+           ST.max = ARG2(scan);  /* max to match */
+           if (cur_eval && cur_eval->u.eval.close_paren &&
+               cur_eval->u.eval.close_paren == (U32)ST.paren) {
+               ST.min=1;
+               ST.max=1;
+           }
+            scan = regnext(NEXTOPER(scan) + NODE_STEP_REGNODE);
+           goto repeat;
+       case CURLY:             /*  /A{m,n}B/ where A is width 1 */
+           ST.paren = 0;
+           ST.min = ARG1(scan);  /* min to match */
+           ST.max = ARG2(scan);  /* max to match */
+           scan = NEXTOPER(scan) + NODE_STEP_REGNODE;
          repeat:
            /*
            * Lookahead to avoid useless match attempts
            * when we know what character comes next.
-           */
-
-           /*
+           *
            * Used to only do .*x and .*?x, but now it allows
            * for )'s, ('s and (?{ ... })'s to be in the way
            * of the quantifier and the EXACT-like node.  -- japhy
            */
 
+           if (ST.min > ST.max) /* XXX make this a compile-time check? */
+               sayNO;
            if (HAS_TEXT(next) || JUMPABLE(next)) {
                U8 *s;
                regnode *text_node = next;
 
-               if (! HAS_TEXT(text_node)) FIND_NEXT_IMPT(text_node);
+               if (! HAS_TEXT(text_node)) 
+                   FIND_NEXT_IMPT(text_node);
 
                if (! HAS_TEXT(text_node))
-                   st->u.plus.c1 = st->u.plus.c2 = CHRTEST_VOID;
+                   ST.c1 = ST.c2 = CHRTEST_VOID;
                else {
-                   if (PL_regkind[(U8)OP(text_node)] == REF) {
-                       st->u.plus.c1 = st->u.plus.c2 = CHRTEST_VOID;
+                   if ( PL_regkind[OP(text_node)] != EXACT ) {
+                       ST.c1 = ST.c2 = CHRTEST_VOID;
                        goto assume_ok_easy;
                    }
-                   else { s = (U8*)STRING(text_node); }
-
-                   if (!UTF) {
-                       st->u.plus.c2 = st->u.plus.c1 = *s;
-                       if (OP(text_node) == EXACTF || OP(text_node) == REFF)
-                           st->u.plus.c2 = PL_fold[st->u.plus.c1];
-                       else if (OP(text_node) == EXACTFL || OP(text_node) == REFFL)
-                           st->u.plus.c2 = PL_fold_locale[st->u.plus.c1];
+                   else
+                       s = (U8*)STRING(text_node);
+                    
+                    /*  Currently we only get here when 
+                        
+                        PL_rekind[OP(text_node)] == EXACT
+                    
+                        if this changes back then the macro for IS_TEXT and 
+                        friends need to change. */
+                   if (!UTF_PATTERN) {
+                       ST.c2 = ST.c1 = *s;
+                       if (IS_TEXTF(text_node))
+                           ST.c2 = PL_fold[ST.c1];
+                       else if (IS_TEXTFL(text_node))
+                           ST.c2 = PL_fold_locale[ST.c1];
                    }
-                   else { /* UTF */
-                       if (OP(text_node) == EXACTF || OP(text_node) == REFF) {
+                   else { /* UTF_PATTERN */
+                       if (IS_TEXTF(text_node)) {
                             STRLEN ulen1, ulen2;
                             U8 tmpbuf1[UTF8_MAXBYTES_CASE+1];
                             U8 tmpbuf2[UTF8_MAXBYTES_CASE+1];
 
                             to_utf8_lower((U8*)s, tmpbuf1, &ulen1);
                             to_utf8_upper((U8*)s, tmpbuf2, &ulen2);
-
-                            st->u.plus.c1 = utf8n_to_uvuni(tmpbuf1, UTF8_MAXBYTES, 0,
-                                                uniflags);
-                            st->u.plus.c2 = utf8n_to_uvuni(tmpbuf2, UTF8_MAXBYTES, 0,
-                                                uniflags);
+#ifdef EBCDIC
+                            ST.c1 = utf8n_to_uvchr(tmpbuf1, UTF8_MAXLEN, 0,
+                                                   ckWARN(WARN_UTF8) ?
+                                                    0 : UTF8_ALLOW_ANY);
+                            ST.c2 = utf8n_to_uvchr(tmpbuf2, UTF8_MAXLEN, 0,
+                                                    ckWARN(WARN_UTF8) ?
+                                                    0 : UTF8_ALLOW_ANY);
+#else
+                            ST.c1 = utf8n_to_uvuni(tmpbuf1, UTF8_MAXBYTES, 0,
+                                                   uniflags);
+                            ST.c2 = utf8n_to_uvuni(tmpbuf2, UTF8_MAXBYTES, 0,
+                                                   uniflags);
+#endif
                        }
                        else {
-                           st->u.plus.c2 = st->u.plus.c1 = utf8n_to_uvchr(s, UTF8_MAXBYTES, 0,
+                           ST.c2 = ST.c1 = utf8n_to_uvchr(s, UTF8_MAXBYTES, 0,
                                                     uniflags);
                        }
                    }
                }
            }
            else
-               st->u.plus.c1 = st->u.plus.c2 = CHRTEST_VOID;
+               ST.c1 = ST.c2 = CHRTEST_VOID;
        assume_ok_easy:
+
+           ST.A = scan;
+           ST.B = next;
            PL_reginput = locinput;
-           if (st->minmod) {
-               st->minmod = 0;
-               if (st->ln && regrepeat(rex, scan, st->ln) < st->ln)
+           if (minmod) {
+               minmod = 0;
+               if (ST.min && regrepeat(rex, ST.A, ST.min, depth) < ST.min)
                    sayNO;
+               ST.count = ST.min;
                locinput = PL_reginput;
-               REGCP_SET(st->u.plus.lastcp);
-               if (st->u.plus.c1 != CHRTEST_VOID) {
-                   st->u.plus.old = locinput;
-                   st->u.plus.count = 0;
-
-                   if  (n == REG_INFTY) {
-                       st->u.plus.e = PL_regeol - 1;
-                       if (do_utf8)
-                           while (UTF8_IS_CONTINUATION(*(U8*)st->u.plus.e))
-                               st->u.plus.e--;
-                   }
-                   else if (do_utf8) {
-                       int m = n - st->ln;
-                       for (st->u.plus.e = locinput;
-                            m >0 && st->u.plus.e + UTF8SKIP(st->u.plus.e) <= PL_regeol; m--)
-                           st->u.plus.e += UTF8SKIP(st->u.plus.e);
+               REGCP_SET(ST.cp);
+               if (ST.c1 == CHRTEST_VOID)
+                   goto curly_try_B_min;
+
+               ST.oldloc = locinput;
+
+               /* set ST.maxpos to the furthest point along the
+                * string that could possibly match */
+               if  (ST.max == REG_INFTY) {
+                   ST.maxpos = PL_regeol - 1;
+                   if (utf8_target)
+                       while (UTF8_IS_CONTINUATION(*(U8*)ST.maxpos))
+                           ST.maxpos--;
+               }
+               else if (utf8_target) {
+                   int m = ST.max - ST.min;
+                   for (ST.maxpos = locinput;
+                        m >0 && ST.maxpos + UTF8SKIP(ST.maxpos) <= PL_regeol; m--)
+                       ST.maxpos += UTF8SKIP(ST.maxpos);
+               }
+               else {
+                   ST.maxpos = locinput + ST.max - ST.min;
+                   if (ST.maxpos >= PL_regeol)
+                       ST.maxpos = PL_regeol - 1;
+               }
+               goto curly_try_B_min_known;
+
+           }
+           else {
+               ST.count = regrepeat(rex, ST.A, ST.max, depth);
+               locinput = PL_reginput;
+               if (ST.count < ST.min)
+                   sayNO;
+               if ((ST.count > ST.min)
+                   && (PL_regkind[OP(ST.B)] == EOL) && (OP(ST.B) != MEOL))
+               {
+                   /* A{m,n} must come at the end of the string, there's
+                    * no point in backing off ... */
+                   ST.min = ST.count;
+                   /* ...except that $ and \Z can match before *and* after
+                      newline at the end.  Consider "\n\n" =~ /\n+\Z\n/.
+                      We may back off by one in this case. */
+                   if (UCHARAT(PL_reginput - 1) == '\n' && OP(ST.B) != EOS)
+                       ST.min--;
+               }
+               REGCP_SET(ST.cp);
+               goto curly_try_B_max;
+           }
+           /* NOTREACHED */
+
+
+       case CURLY_B_min_known_fail:
+           /* failed to find B in a non-greedy match where c1,c2 valid */
+           if (ST.paren && ST.count)
+               PL_regoffs[ST.paren].end = -1;
+
+           PL_reginput = locinput;     /* Could be reset... */
+           REGCP_UNWIND(ST.cp);
+           /* Couldn't or didn't -- move forward. */
+           ST.oldloc = locinput;
+           if (utf8_target)
+               locinput += UTF8SKIP(locinput);
+           else
+               locinput++;
+           ST.count++;
+         curly_try_B_min_known:
+            /* find the next place where 'B' could work, then call B */
+           {
+               int n;
+               if (utf8_target) {
+                   n = (ST.oldloc == locinput) ? 0 : 1;
+                   if (ST.c1 == ST.c2) {
+                       STRLEN len;
+                       /* set n to utf8_distance(oldloc, locinput) */
+                       while (locinput <= ST.maxpos &&
+                              utf8n_to_uvchr((U8*)locinput,
+                                             UTF8_MAXBYTES, &len,
+                                             uniflags) != (UV)ST.c1) {
+                           locinput += len;
+                           n++;
+                       }
                    }
                    else {
-                       st->u.plus.e = locinput + n - st->ln;
-                       if (st->u.plus.e >= PL_regeol)
-                           st->u.plus.e = PL_regeol - 1;
-                   }
-                   while (1) {
-                       /* Find place 'next' could work */
-                       if (!do_utf8) {
-                           if (st->u.plus.c1 == st->u.plus.c2) {
-                               while (locinput <= st->u.plus.e &&
-                                      UCHARAT(locinput) != st->u.plus.c1)
-                                   locinput++;
-                           } else {
-                               while (locinput <= st->u.plus.e
-                                      && UCHARAT(locinput) != st->u.plus.c1
-                                      && UCHARAT(locinput) != st->u.plus.c2)
-                                   locinput++;
-                           }
-                           st->u.plus.count = locinput - st->u.plus.old;
-                       }
-                       else {
-                           if (st->u.plus.c1 == st->u.plus.c2) {
-                               STRLEN len;
-                               /* count initialised to
-                                * utf8_distance(old, locinput) */
-                               while (locinput <= st->u.plus.e &&
-                                      utf8n_to_uvchr((U8*)locinput,
-                                                     UTF8_MAXBYTES, &len,
-                                                     uniflags) != (UV)st->u.plus.c1) {
-                                   locinput += len;
-                                   st->u.plus.count++;
-                               }
-                           } else {
-                               /* count initialised to
-                                * utf8_distance(old, locinput) */
-                               while (locinput <= st->u.plus.e) {
-                                   STRLEN len;
-                                   const UV c = utf8n_to_uvchr((U8*)locinput,
-                                                         UTF8_MAXBYTES, &len,
-                                                         uniflags);
-                                   if (c == (UV)st->u.plus.c1 || c == (UV)st->u.plus.c2)
-                                       break;
-                                   locinput += len;
-                                   st->u.plus.count++;
-                               }
-                           }
-                       }
-                       if (locinput > st->u.plus.e)
-                           sayNO;
-                       /* PL_reginput == old now */
-                       if (locinput != st->u.plus.old) {
-                           st->ln = 1; /* Did some */
-                           if (regrepeat(rex, scan, st->u.plus.count) < st->u.plus.count)
-                               sayNO;
+                       /* set n to utf8_distance(oldloc, locinput) */
+                       while (locinput <= ST.maxpos) {
+                           STRLEN len;
+                           const UV c = utf8n_to_uvchr((U8*)locinput,
+                                                 UTF8_MAXBYTES, &len,
+                                                 uniflags);
+                           if (c == (UV)ST.c1 || c == (UV)ST.c2)
+                               break;
+                           locinput += len;
+                           n++;
                        }
-                       /* PL_reginput == locinput now */
-                       TRYPAREN(st->u.plus.paren, st->ln, locinput, PLUS1);
-                       /*** all unsaved local vars undefined at this point */
-                       PL_reginput = locinput; /* Could be reset... */
-                       REGCP_UNWIND(st->u.plus.lastcp);
-                       /* Couldn't or didn't -- move forward. */
-                       st->u.plus.old = locinput;
-                       if (do_utf8)
-                           locinput += UTF8SKIP(locinput);
-                       else
-                           locinput++;
-                       st->u.plus.count = 1;
                    }
                }
-               else
-               while (n >= st->ln || (n == REG_INFTY && st->ln > 0)) { /* ln overflow ? */
-                   UV c;
-                   if (st->u.plus.c1 != CHRTEST_VOID) {
-                       if (do_utf8)
-                           c = utf8n_to_uvchr((U8*)PL_reginput,
-                                              UTF8_MAXBYTES, 0,
-                                              uniflags);
-                       else
-                           c = UCHARAT(PL_reginput);
-                       /* If it could work, try it. */
-                       if (c == (UV)st->u.plus.c1 || c == (UV)st->u.plus.c2)
-                       {
-                           TRYPAREN(st->u.plus.paren, st->ln, PL_reginput, PLUS2);
-                           /*** all unsaved local vars undefined at this point */
-                           REGCP_UNWIND(st->u.plus.lastcp);
-                       }
-                   }
-                   /* If it could work, try it. */
-                   else if (st->u.plus.c1 == CHRTEST_VOID)
-                   {
-                       TRYPAREN(st->u.plus.paren, st->ln, PL_reginput, PLUS3);
-                       /*** all unsaved local vars undefined at this point */
-                       REGCP_UNWIND(st->u.plus.lastcp);
+               else {
+                   if (ST.c1 == ST.c2) {
+                       while (locinput <= ST.maxpos &&
+                              UCHARAT(locinput) != ST.c1)
+                           locinput++;
                    }
-                   /* Couldn't or didn't -- move forward. */
-                   PL_reginput = locinput;
-                   if (regrepeat(rex, scan, 1)) {
-                       st->ln++;
-                       locinput = PL_reginput;
+                   else {
+                       while (locinput <= ST.maxpos
+                              && UCHARAT(locinput) != ST.c1
+                              && UCHARAT(locinput) != ST.c2)
+                           locinput++;
                    }
-                   else
+                   n = locinput - ST.oldloc;
+               }
+               if (locinput > ST.maxpos)
+                   sayNO;
+               /* PL_reginput == oldloc now */
+               if (n) {
+                   ST.count += n;
+                   if (regrepeat(rex, ST.A, n, depth) < n)
                        sayNO;
                }
+               PL_reginput = locinput;
+               CURLY_SETPAREN(ST.paren, ST.count);
+               if (cur_eval && cur_eval->u.eval.close_paren && 
+                   cur_eval->u.eval.close_paren == (U32)ST.paren) {
+                   goto fake_end;
+               }
+               PUSH_STATE_GOTO(CURLY_B_min_known, ST.B);
            }
-           else {
-               n = regrepeat(rex, scan, n);
+           /* NOTREACHED */
+
+
+       case CURLY_B_min_fail:
+           /* failed to find B in a non-greedy match where c1,c2 invalid */
+           if (ST.paren && ST.count)
+               PL_regoffs[ST.paren].end = -1;
+
+           REGCP_UNWIND(ST.cp);
+           /* failed -- move forward one */
+           PL_reginput = locinput;
+           if (regrepeat(rex, ST.A, 1, depth)) {
+               ST.count++;
                locinput = PL_reginput;
-               if (st->ln < n && PL_regkind[(U8)OP(next)] == EOL &&
-                   (OP(next) != MEOL ||
-                       OP(next) == SEOL || OP(next) == EOS))
+               if (ST.count <= ST.max || (ST.max == REG_INFTY &&
+                       ST.count > 0)) /* count overflow ? */
                {
-                   st->ln = n;                 /* why back off? */
-                   /* ...because $ and \Z can match before *and* after
-                      newline at the end.  Consider "\n\n" =~ /\n+\Z\n/.
-                      We should back off by one in this case. */
-                   if (UCHARAT(PL_reginput - 1) == '\n' && OP(next) != EOS)
-                       st->ln--;
-               }
-               REGCP_SET(st->u.plus.lastcp);
-               {
-                   UV c = 0;
-                   while (n >= st->ln) {
-                       if (st->u.plus.c1 != CHRTEST_VOID) {
-                           if (do_utf8)
-                               c = utf8n_to_uvchr((U8*)PL_reginput,
-                                                  UTF8_MAXBYTES, 0,
-                                                  uniflags);
-                           else
-                               c = UCHARAT(PL_reginput);
-                       }
-                       /* If it could work, try it. */
-                       if (st->u.plus.c1 == CHRTEST_VOID || c == (UV)st->u.plus.c1 || c == (UV)st->u.plus.c2)
-                           {
-                               TRYPAREN(st->u.plus.paren, n, PL_reginput, PLUS4);
-                               /*** all unsaved local vars undefined at this point */
-                               REGCP_UNWIND(st->u.plus.lastcp);
-                           }
-                       /* Couldn't or didn't -- back up. */
-                       n--;
-                       PL_reginput = locinput = HOPc(locinput, -1);
-                   }
+                 curly_try_B_min:
+                   CURLY_SETPAREN(ST.paren, ST.count);
+                   if (cur_eval && cur_eval->u.eval.close_paren &&
+                       cur_eval->u.eval.close_paren == (U32)ST.paren) {
+                        goto fake_end;
+                    }
+                   PUSH_STATE_GOTO(CURLY_B_min, ST.B);
                }
            }
            sayNO;
-           break;
+           /* NOTREACHED */
+
+
+       curly_try_B_max:
+           /* a successful greedy match: now try to match B */
+            if (cur_eval && cur_eval->u.eval.close_paren &&
+                cur_eval->u.eval.close_paren == (U32)ST.paren) {
+                goto fake_end;
+            }
+           {
+               UV c = 0;
+               if (ST.c1 != CHRTEST_VOID)
+                   c = utf8_target ? utf8n_to_uvchr((U8*)PL_reginput,
+                                          UTF8_MAXBYTES, 0, uniflags)
+                               : (UV) UCHARAT(PL_reginput);
+               /* If it could work, try it. */
+               if (ST.c1 == CHRTEST_VOID || c == (UV)ST.c1 || c == (UV)ST.c2) {
+                   CURLY_SETPAREN(ST.paren, ST.count);
+                   PUSH_STATE_GOTO(CURLY_B_max, ST.B);
+                   /* NOTREACHED */
+               }
+           }
+           /* FALL THROUGH */
+       case CURLY_B_max_fail:
+           /* failed to find B in a greedy match */
+           if (ST.paren && ST.count)
+               PL_regoffs[ST.paren].end = -1;
+
+           REGCP_UNWIND(ST.cp);
+           /*  back up. */
+           if (--ST.count < ST.min)
+               sayNO;
+           PL_reginput = locinput = HOPc(locinput, -1);
+           goto curly_try_B_max;
+
+#undef ST
+
        case END:
+           fake_end:
+           if (cur_eval) {
+               /* we've just finished A in /(??{A})B/; now continue with B */
+               I32 tmpix;
+               st->u.eval.toggle_reg_flags
+                           = cur_eval->u.eval.toggle_reg_flags;
+               PL_reg_flags ^= st->u.eval.toggle_reg_flags; 
+
+               st->u.eval.prev_rex = rex_sv;           /* inner */
+               SETREX(rex_sv,cur_eval->u.eval.prev_rex);
+               rex = (struct regexp *)SvANY(rex_sv);
+               rexi = RXi_GET(rex);
+               cur_curlyx = cur_eval->u.eval.prev_curlyx;
+               ReREFCNT_inc(rex_sv);
+               st->u.eval.cp = regcppush(0);   /* Save *all* the positions. */
+
+               /* rex was changed so update the pointer in PL_reglastparen and PL_reglastcloseparen */
+               PL_reglastparen = &rex->lastparen;
+               PL_reglastcloseparen = &rex->lastcloseparen;
+
+               REGCP_SET(st->u.eval.lastcp);
+               PL_reginput = locinput;
+
+               /* Restore parens of the outer rex without popping the
+                * savestack */
+               tmpix = PL_savestack_ix;
+               PL_savestack_ix = cur_eval->u.eval.lastcp;
+               regcppop(rex);
+               PL_savestack_ix = tmpix;
+
+               st->u.eval.prev_eval = cur_eval;
+               cur_eval = cur_eval->u.eval.prev_eval;
+               DEBUG_EXECUTE_r(
+                   PerlIO_printf(Perl_debug_log, "%*s  EVAL trying tail ... %"UVxf"\n",
+                                     REPORT_CODE_OFF+depth*2, "",PTR2UV(cur_eval)););
+                if ( nochange_depth )
+                   nochange_depth--;
+
+                PUSH_YES_STATE_GOTO(EVAL_AB,
+                       st->u.eval.prev_eval->u.eval.B); /* match B */
+           }
+
            if (locinput < reginfo->till) {
                DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
                                      "%sMatch possible, but length=%ld is smaller than requested=%ld, failing!%s\n",
@@ -4253,40 +5169,44 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                                      (long)(locinput - PL_reg_starttry),
                                      (long)(reginfo->till - PL_reg_starttry),
                                      PL_colors[5]));
-               sayNO_FINAL;            /* Cannot match: too short. */
+                                                     
+               sayNO_SILENT;           /* Cannot match: too short. */
            }
            PL_reginput = locinput;     /* put where regtry can find it */
-           sayYES_FINAL;               /* Success! */
+           sayYES;                     /* Success! */
 
        case SUCCEED: /* successful SUSPEND/UNLESSM/IFMATCH/CURLYM */
            DEBUG_EXECUTE_r(
            PerlIO_printf(Perl_debug_log,
                "%*s  %ssubpattern success...%s\n",
-               REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4], PL_colors[5]));
+               REPORT_CODE_OFF+depth*2, "", PL_colors[4], PL_colors[5]));
            PL_reginput = locinput;     /* put where regtry can find it */
-           sayYES_FINAL;               /* Success! */
+           sayYES;                     /* Success! */
 
-       case SUSPEND:   /* (?>FOO) */
-           st->u.ifmatch.wanted = 1;
+#undef  ST
+#define ST st->u.ifmatch
+
+       case SUSPEND:   /* (?>A) */
+           ST.wanted = 1;
            PL_reginput = locinput;
            goto do_ifmatch;    
 
-       case UNLESSM:   /* -ve lookaround: (?!FOO), or with flags, (?<!foo) */
-           st->u.ifmatch.wanted = 0;
+       case UNLESSM:   /* -ve lookaround: (?!A), or with flags, (?<!A) */
+           ST.wanted = 0;
            goto ifmatch_trivial_fail_test;
 
-       case IFMATCH:   /* +ve lookaround: (?=FOO), or with flags, (?<=foo) */
-           st->u.ifmatch.wanted = 1;
+       case IFMATCH:   /* +ve lookaround: (?=A), or with flags, (?<=A) */
+           ST.wanted = 1;
          ifmatch_trivial_fail_test:
            if (scan->flags) {
                char * const s = HOPBACKc(locinput, scan->flags);
                if (!s) {
                    /* trivial fail */
-                   if (st->logical) {
-                       st->logical = 0;
-                       st->sw = 1 - st->u.ifmatch.wanted;
+                   if (logical) {
+                       logical = 0;
+                       sw = 1 - cBOOL(ST.wanted);
                    }
-                   else if (st->u.ifmatch.wanted)
+                   else if (ST.wanted)
                        sayNO;
                    next = scan + ARG(scan);
                    if (next == scan)
@@ -4299,67 +5219,245 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
                PL_reginput = locinput;
 
          do_ifmatch:
-           /* resume to current state on success */
-           st->u.yes.prev_yes_state = yes_state;
-           yes_state = st;
-           PUSH_STATE(newst, resume_IFMATCH);
-           st = newst;
-           next = NEXTOPER(NEXTOPER(scan));
-           break;
+           ST.me = scan;
+           ST.logical = logical;
+           logical = 0; /* XXX: reset state of logical once it has been saved into ST */
+           
+           /* execute body of (?...A) */
+           PUSH_YES_STATE_GOTO(IFMATCH_A, NEXTOPER(NEXTOPER(scan)));
+           /* NOTREACHED */
+
+       case IFMATCH_A_fail: /* body of (?...A) failed */
+           ST.wanted = !ST.wanted;
+           /* FALL THROUGH */
+
+       case IFMATCH_A: /* body of (?...A) succeeded */
+           if (ST.logical) {
+               sw = cBOOL(ST.wanted);
+           }
+           else if (!ST.wanted)
+               sayNO;
+
+           if (OP(ST.me) == SUSPEND)
+               locinput = PL_reginput;
+           else {
+               locinput = PL_reginput = st->locinput;
+               nextchr = UCHARAT(locinput);
+           }
+           scan = ST.me + ARG(ST.me);
+           if (scan == ST.me)
+               scan = NULL;
+           continue; /* execute B */
+
+#undef ST
 
        case LONGJMP:
            next = scan + ARG(scan);
            if (next == scan)
                next = NULL;
            break;
+       case COMMIT:
+           reginfo->cutpoint = PL_regeol;
+           /* FALLTHROUGH */
+       case PRUNE:
+           PL_reginput = locinput;
+           if (!scan->flags)
+               sv_yes_mark = sv_commit = MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
+           PUSH_STATE_GOTO(COMMIT_next,next);
+           /* NOTREACHED */
+       case COMMIT_next_fail:
+           no_final = 1;    
+           /* FALLTHROUGH */       
+       case OPFAIL:
+           sayNO;
+           /* NOTREACHED */
+
+#define ST st->u.mark
+        case MARKPOINT:
+            ST.prev_mark = mark_state;
+            ST.mark_name = sv_commit = sv_yes_mark 
+                = MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
+            mark_state = st;
+            ST.mark_loc = PL_reginput = locinput;
+            PUSH_YES_STATE_GOTO(MARKPOINT_next,next);
+            /* NOTREACHED */
+        case MARKPOINT_next:
+            mark_state = ST.prev_mark;
+            sayYES;
+            /* NOTREACHED */
+        case MARKPOINT_next_fail:
+            if (popmark && sv_eq(ST.mark_name,popmark)) 
+            {
+                if (ST.mark_loc > startpoint)
+                   reginfo->cutpoint = HOPBACKc(ST.mark_loc, 1);
+                popmark = NULL; /* we found our mark */
+                sv_commit = ST.mark_name;
+
+                DEBUG_EXECUTE_r({
+                        PerlIO_printf(Perl_debug_log,
+                           "%*s  %ssetting cutpoint to mark:%"SVf"...%s\n",
+                           REPORT_CODE_OFF+depth*2, "", 
+                           PL_colors[4], SVfARG(sv_commit), PL_colors[5]);
+               });
+            }
+            mark_state = ST.prev_mark;
+            sv_yes_mark = mark_state ? 
+                mark_state->u.mark.mark_name : NULL;
+            sayNO;
+            /* NOTREACHED */
+        case SKIP:
+            PL_reginput = locinput;
+            if (scan->flags) {
+                /* (*SKIP) : if we fail we cut here*/
+                ST.mark_name = NULL;
+                ST.mark_loc = locinput;
+                PUSH_STATE_GOTO(SKIP_next,next);    
+            } else {
+                /* (*SKIP:NAME) : if there is a (*MARK:NAME) fail where it was, 
+                   otherwise do nothing.  Meaning we need to scan 
+                 */
+                regmatch_state *cur = mark_state;
+                SV *find = MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
+                
+                while (cur) {
+                    if ( sv_eq( cur->u.mark.mark_name, 
+                                find ) ) 
+                    {
+                        ST.mark_name = find;
+                        PUSH_STATE_GOTO( SKIP_next, next );
+                    }
+                    cur = cur->u.mark.prev_mark;
+                }
+            }    
+            /* Didn't find our (*MARK:NAME) so ignore this (*SKIP:NAME) */
+            break;    
+       case SKIP_next_fail:
+           if (ST.mark_name) {
+               /* (*CUT:NAME) - Set up to search for the name as we 
+                  collapse the stack*/
+               popmark = ST.mark_name;    
+           } else {
+               /* (*CUT) - No name, we cut here.*/
+               if (ST.mark_loc > startpoint)
+                   reginfo->cutpoint = HOPBACKc(ST.mark_loc, 1);
+               /* but we set sv_commit to latest mark_name if there
+                  is one so they can test to see how things lead to this
+                  cut */    
+                if (mark_state) 
+                    sv_commit=mark_state->u.mark.mark_name;                
+            } 
+            no_final = 1; 
+            sayNO;
+            /* NOTREACHED */
+#undef ST
+        case FOLDCHAR:
+            n = ARG(scan);
+            if ( n == (U32)what_len_TRICKYFOLD(locinput,utf8_target,ln) ) {
+                locinput += ln;
+            } else if ( 0xDF == n && !utf8_target && !UTF_PATTERN ) {
+                sayNO;
+            } else  {
+                U8 folded[UTF8_MAXBYTES_CASE+1];
+                STRLEN foldlen;
+                const char * const l = locinput;
+                char *e = PL_regeol;
+                to_uni_fold(n, folded, &foldlen);
+
+               if (! foldEQ_utf8((const char*) folded, 0,  foldlen, 1,
+                              l, &e, 0,  utf8_target)) {
+                        sayNO;
+                }
+                locinput = e;
+            } 
+            nextchr = UCHARAT(locinput);  
+            break;
+        case LNBREAK:
+            if ((n=is_LNBREAK(locinput,utf8_target))) {
+                locinput += n;
+                nextchr = UCHARAT(locinput);
+            } else
+                sayNO;
+            break;
+
+#define CASE_CLASS(nAmE)                              \
+        case nAmE:                                    \
+            if ((n=is_##nAmE(locinput,utf8_target))) {    \
+                locinput += n;                        \
+                nextchr = UCHARAT(locinput);          \
+            } else                                    \
+                sayNO;                                \
+            break;                                    \
+        case N##nAmE:                                 \
+            if ((n=is_##nAmE(locinput,utf8_target))) {    \
+                sayNO;                                \
+            } else {                                  \
+                locinput += UTF8SKIP(locinput);       \
+                nextchr = UCHARAT(locinput);          \
+            }                                         \
+            break
+
+        CASE_CLASS(VERTWS);
+        CASE_CLASS(HORIZWS);
+#undef CASE_CLASS
+
        default:
            PerlIO_printf(Perl_error_log, "%"UVxf" %d\n",
                          PTR2UV(scan), OP(scan));
            Perl_croak(aTHX_ "regexp memory corruption");
-       }
+           
+       } /* end switch */ 
 
-      reenter:
-       scan = next;
-       continue;
+        /* switch break jumps here */
+       scan = next; /* prepare to execute the next op and ... */
+       continue;    /* ... jump back to the top, reusing st */
        /* NOTREACHED */
 
-       /* simulate recursively calling regmatch(), but without actually
-        * recursing - ie save the current state on the heap rather than on
-        * the stack, then re-enter the loop. This avoids complex regexes
-        * blowing the processor stack */
-
-      start_recurse:
+      push_yes_state:
+       /* push a state that backtracks on success */
+       st->u.yes.prev_yes_state = yes_state;
+       yes_state = st;
+       /* FALL THROUGH */
+      push_state:
+       /* push a new regex state, then continue at scan  */
        {
-           /* push new state */
-           regmatch_state *oldst = st;
-
+           regmatch_state *newst;
+
+           DEBUG_STACK_r({
+               regmatch_state *cur = st;
+               regmatch_state *curyes = yes_state;
+               int curd = depth;
+               regmatch_slab *slab = PL_regmatch_slab;
+                for (;curd > -1;cur--,curd--) {
+                    if (cur < SLAB_FIRST(slab)) {
+                       slab = slab->prev;
+                       cur = SLAB_LAST(slab);
+                    }
+                    PerlIO_printf(Perl_error_log, "%*s#%-3d %-10s %s\n",
+                        REPORT_CODE_OFF + 2 + depth * 2,"",
+                        curd, PL_reg_name[cur->resume_state],
+                        (curyes == cur) ? "yes" : ""
+                    );
+                    if (curyes == cur)
+                       curyes = cur->u.yes.prev_yes_state;
+                }
+            } else 
+                DEBUG_STATE_pp("push")
+            );
            depth++;
+           st->locinput = locinput;
+           newst = st+1; 
+           if (newst >  SLAB_LAST(PL_regmatch_slab))
+               newst = S_push_slab(aTHX);
+           PL_regmatch_state = newst;
 
-           /* grab the next free state slot */
-           st++;
-           if (st >  SLAB_LAST(PL_regmatch_slab))
-               st = S_push_slab(aTHX);
-           PL_regmatch_state = st;
-
-           oldst->next = next;
-           oldst->n = n;
-           oldst->locinput = locinput;
-
-           st->cc = oldst->cc;
            locinput = PL_reginput;
-           nextchr = UCHARAT(locinput);
-           st->minmod = 0;
-           st->sw = 0;
-           st->logical = 0;
-           st->unwind = 0;
-#ifdef DEBUGGING
-           PL_regindent++;
-#endif
+           nextchr = UCHARAT(locinput);
+           st = newst;
+           continue;
+           /* NOTREACHED */
        }
     }
 
-
-
     /*
     * We get here only if there's trouble -- normally "case END" is
     * the terminating point.
@@ -4368,19 +5466,28 @@ S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
     /*NOTREACHED*/
     sayNO;
 
-yes_final:
-
+yes:
     if (yes_state) {
        /* we have successfully completed a subexpression, but we must now
         * pop to the state marked by yes_state and continue from there */
-
-       /*XXX tmp for CURLYM*/
-       regmatch_slab * const oslab = PL_regmatch_slab;
-       regmatch_state * const ost = st;
-       regmatch_state * const oys = yes_state;
-       int odepth = depth;
-
        assert(st != yes_state);
+#ifdef DEBUGGING
+       while (st != yes_state) {
+           st--;
+           if (st < SLAB_FIRST(PL_regmatch_slab)) {
+               PL_regmatch_slab = PL_regmatch_slab->prev;
+               st = SLAB_LAST(PL_regmatch_slab);
+           }
+           DEBUG_STATE_r({
+               if (no_final) {
+                   DEBUG_STATE_pp("pop (no final)");        
+               } else {
+                   DEBUG_STATE_pp("pop (yes)");
+               }
+           });
+           depth--;
+       }
+#else
        while (yes_state < SLAB_FIRST(PL_regmatch_slab)
            || yes_state > SLAB_LAST(PL_regmatch_slab))
        {
@@ -4390,283 +5497,92 @@ yes_final:
            st = SLAB_LAST(PL_regmatch_slab);
        }
        depth -= (st - yes_state);
-       DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "POP STATE TO (%d)\n", depth));
+#endif
        st = yes_state;
        yes_state = st->u.yes.prev_yes_state;
        PL_regmatch_state = st;
-
-       switch (st->resume_state) {
-       case resume_EVAL:
-           if (st->u.eval.toggleutf)
-               PL_reg_flags ^= RF_utf8;
-           ReREFCNT_dec(rex);
-           rex = st->u.eval.prev_rex;
-           /* XXXX This is too dramatic a measure... */
-           PL_reg_maxiter = 0;
-           /* Restore parens of the caller without popping the
-            * savestack */
-           {
-               const I32 tmp = PL_savestack_ix;
-               PL_savestack_ix = st->u.eval.lastcp;
-               regcppop(rex);
-               PL_savestack_ix = tmp;
-           }
-           PL_reginput = locinput;
-            /* continue at the node following the (??{...}) */
-           next        = st->next;
-           goto reenter;
-
-       case resume_IFMATCH:
-           if (st->logical) {
-               st->logical = 0;
-               st->sw = st->u.ifmatch.wanted;
-           }
-           else if (!st->u.ifmatch.wanted)
-               sayNO;
-
-           if (OP(st->scan) == SUSPEND)
-               locinput = PL_reginput;
-           else {
-               locinput = PL_reginput = st->locinput;
-               nextchr = UCHARAT(locinput);
-           }
-           next = st->scan + ARG(st->scan);
-           if (next == st->scan)
-               next = NULL;
-           goto reenter;
-
-       /* XXX tmp  don't handle yes_state yet */
-       case resume_CURLYM1:
-       case resume_CURLYM2:
-       case resume_CURLYM3:
-           PL_regmatch_slab =oslab;
-           st = ost;
-           PL_regmatch_state = st;
-           depth = odepth;
-           yes_state = oys;
-           DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "XXX revering a CURLYM\n"));
-           goto yes;
-
-       default:
-           Perl_croak(aTHX_ "unexpected yes reume state");
-       }
+        
+        if (no_final) {
+            locinput= st->locinput;
+            nextchr = UCHARAT(locinput);
+        }
+       state_num = st->resume_state + no_final;
+       goto reenter_switch;
     }
 
     DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch successful!%s\n",
                          PL_colors[4], PL_colors[5]));
-yes:
-#ifdef DEBUGGING
-    PL_regindent--;
-#endif
 
-    result = 1;
-    /* XXX this is duplicate(ish) code to that in the do_no section.
-     * eventually a yes should just pop the stack back to the current
-     * yes_state */
-    if (depth) {
-       /* restore previous state and re-enter */
-       POP_STATE;
-
-       switch (st->resume_state) {
-       case resume_TRIE1:
-           goto resume_point_TRIE1;
-       case resume_TRIE2:
-           goto resume_point_TRIE2;
-       case resume_CURLYX:
-           goto resume_point_CURLYX;
-       case resume_WHILEM1:
-           goto resume_point_WHILEM1;
-       case resume_WHILEM2:
-           goto resume_point_WHILEM2;
-       case resume_WHILEM3:
-           goto resume_point_WHILEM3;
-       case resume_WHILEM4:
-           goto resume_point_WHILEM4;
-       case resume_WHILEM5:
-           goto resume_point_WHILEM5;
-       case resume_WHILEM6:
-           goto resume_point_WHILEM6;
-       case resume_CURLYM1:
-           goto resume_point_CURLYM1;
-       case resume_CURLYM2:
-           goto resume_point_CURLYM2;
-       case resume_CURLYM3:
-           goto resume_point_CURLYM3;
-       case resume_PLUS1:
-           goto resume_point_PLUS1;
-       case resume_PLUS2:
-           goto resume_point_PLUS2;
-       case resume_PLUS3:
-           goto resume_point_PLUS3;
-       case resume_PLUS4:
-           goto resume_point_PLUS4;
-
-       case resume_IFMATCH:
-       case resume_EVAL:
-       default:
-           Perl_croak(aTHX_ "regexp resume memory corruption");
-       }
+    if (PL_reg_eval_set) {
+       /* each successfully executed (?{...}) block does the equivalent of
+        *   local $^R = do {...}
+        * When popping the save stack, all these locals would be undone;
+        * bypass this by setting the outermost saved $^R to the latest
+        * value */
+       if (oreplsv != GvSV(PL_replgv))
+           sv_setsv(oreplsv, GvSV(PL_replgv));
     }
+    result = 1;
     goto final_exit;
 
 no:
     DEBUG_EXECUTE_r(
        PerlIO_printf(Perl_debug_log,
-                     "%*s  %sfailed...%s\n",
-                     REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4], PL_colors[5])
+            "%*s  %sfailed...%s\n",
+            REPORT_CODE_OFF+depth*2, "", 
+            PL_colors[4], PL_colors[5])
        );
-    goto do_no;
-no_final:
-do_no:
-    if (st->unwind) {
-       re_unwind_t * const uw = SSPTRt(st->unwind,re_unwind_t);
-
-       switch (uw->type) {
-       case RE_UNWIND_BRANCH:
-       case RE_UNWIND_BRANCHJ:
-       {
-           re_unwind_branch_t * const uwb = &(uw->branch);
-           const I32 lastparen = uwb->lastparen;
-       
-           REGCP_UNWIND(uwb->lastcp);
-           for (n = *PL_reglastparen; n > lastparen; n--)
-               PL_regendp[n] = -1;
-           *PL_reglastparen = n;
-           scan = next = uwb->next;
-           st->minmod = uwb->minmod;
-           if ( !scan ||
-                OP(scan) != (uwb->type == RE_UNWIND_BRANCH
-                             ? BRANCH : BRANCHJ) ) {           /* Failure */
-               st->unwind = uwb->prev;
-#ifdef DEBUGGING
-               PL_regindent--;
-#endif
-               goto do_no;
-           }
-           /* Have more choice yet.  Reuse the same uwb.  */
-           if ((n = (uwb->type == RE_UNWIND_BRANCH
-                     ? NEXT_OFF(next) : ARG(next))))
-               next += n;
-           else
-               next = NULL;    /* XXXX Needn't unwinding in this case... */
-           uwb->next = next;
-           next = NEXTOPER(scan);
-           if (uwb->type == RE_UNWIND_BRANCHJ)
-               next = NEXTOPER(next);
-           locinput = uwb->locinput;
-           nextchr = uwb->nextchr;
-#ifdef DEBUGGING
-           PL_regindent = uwb->regindent;
-#endif
-
-           goto reenter;
-       }
-       /* NOTREACHED */
-       default:
-           Perl_croak(aTHX_ "regexp unwind memory corruption");
-       }
-       /* NOTREACHED */
-    }
-
-#ifdef DEBUGGING
-    PL_regindent--;
-#endif
-    result = 0;
 
+no_silent:
+    if (no_final) {
+        if (yes_state) {
+            goto yes;
+        } else {
+            goto final_exit;
+        }
+    }    
     if (depth) {
        /* there's a previous state to backtrack to */
-       POP_STATE;
-       switch (st->resume_state) {
-       case resume_TRIE1:
-           goto resume_point_TRIE1;
-       case resume_TRIE2:
-           goto resume_point_TRIE2;
-       case resume_EVAL:
-           /* we have failed an (??{...}). Restore state to the outer re
-            * then re-throw the failure */
-           if (st->u.eval.toggleutf)
-               PL_reg_flags ^= RF_utf8;
-           ReREFCNT_dec(rex);
-           rex = st->u.eval.prev_rex;
-           yes_state = st->u.yes.prev_yes_state;
-
-           /* XXXX This is too dramatic a measure... */
-           PL_reg_maxiter = 0;
+       st--;
+       if (st < SLAB_FIRST(PL_regmatch_slab)) {
+           PL_regmatch_slab = PL_regmatch_slab->prev;
+           st = SLAB_LAST(PL_regmatch_slab);
+       }
+       PL_regmatch_state = st;
+       locinput= st->locinput;
+       nextchr = UCHARAT(locinput);
 
-           PL_reginput = locinput;
-           REGCP_UNWIND(st->u.eval.lastcp);
-           regcppop(rex);
-           goto do_no;
-
-       case resume_CURLYX:
-           goto resume_point_CURLYX;
-       case resume_WHILEM1:
-           goto resume_point_WHILEM1;
-       case resume_WHILEM2:
-           goto resume_point_WHILEM2;
-       case resume_WHILEM3:
-           goto resume_point_WHILEM3;
-       case resume_WHILEM4:
-           goto resume_point_WHILEM4;
-       case resume_WHILEM5:
-           goto resume_point_WHILEM5;
-       case resume_WHILEM6:
-           goto resume_point_WHILEM6;
-       case resume_CURLYM1:
-           goto resume_point_CURLYM1;
-       case resume_CURLYM2:
-           goto resume_point_CURLYM2;
-       case resume_CURLYM3:
-           goto resume_point_CURLYM3;
-       case resume_IFMATCH:
+       DEBUG_STATE_pp("pop");
+       depth--;
+       if (yes_state == st)
            yes_state = st->u.yes.prev_yes_state;
-           if (st->logical) {
-               st->logical = 0;
-               st->sw = !st->u.ifmatch.wanted;
-           }
-           else if (st->u.ifmatch.wanted)
-               sayNO;
 
-           assert(OP(scan) != SUSPEND); /* XXX DAPM tmp */
-           locinput = PL_reginput = st->locinput;
-           nextchr = UCHARAT(locinput);
-           next = scan + ARG(scan);
-           if (next == scan)
-               next = NULL;
-           goto reenter;
-
-       case resume_PLUS1:
-           goto resume_point_PLUS1;
-       case resume_PLUS2:
-           goto resume_point_PLUS2;
-       case resume_PLUS3:
-           goto resume_point_PLUS3;
-       case resume_PLUS4:
-           goto resume_point_PLUS4;
-       default:
-           Perl_croak(aTHX_ "regexp resume memory corruption");
-       }
+       state_num = st->resume_state + 1; /* failure = success + 1 */
+       goto reenter_switch;
     }
+    result = 0;
 
-final_exit:
-
-    /* restore original high-water mark */
-    PL_regmatch_slab  = orig_slab;
-    PL_regmatch_state = orig_state;
-
-    /* free all slabs above current one */
-    if (orig_slab->next) {
-       regmatch_slab *sl = orig_slab->next;
-       orig_slab->next = NULL;
-       while (sl) {
-           regmatch_slab * const osl = sl;
-           sl = sl->next;
-           Safefree(osl);
-       }
+  final_exit:
+    if (rex->intflags & PREGf_VERBARG_SEEN) {
+        SV *sv_err = get_sv("REGERROR", 1);
+        SV *sv_mrk = get_sv("REGMARK", 1);
+        if (result) {
+            sv_commit = &PL_sv_no;
+            if (!sv_yes_mark) 
+                sv_yes_mark = &PL_sv_yes;
+        } else {
+            if (!sv_commit) 
+                sv_commit = &PL_sv_yes;
+            sv_yes_mark = &PL_sv_no;
+        }
+        sv_setsv(sv_err, sv_commit);
+        sv_setsv(sv_mrk, sv_yes_mark);
     }
 
-    return result;
+    /* clean up; in particular, free all slabs above current one */
+    LEAVE_SCOPE(oldsave);
 
+    return result;
 }
 
 /*
@@ -4678,14 +5594,19 @@ final_exit:
  * rather than incrementing count on every character.  [Er, except utf8.]]
  */
 STATIC I32
-S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
+S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max, int depth)
 {
     dVAR;
     register char *scan;
     register I32 c;
     register char *loceol = PL_regeol;
     register I32 hardcount = 0;
-    register bool do_utf8 = PL_reg_match_utf8;
+    register bool utf8_target = PL_reg_match_utf8;
+#ifndef DEBUGGING
+    PERL_UNUSED_ARG(depth);
+#endif
+
+    PERL_ARGS_ASSERT_REGREPEAT;
 
     scan = PL_reginput;
     if (max == REG_INFTY)
@@ -4694,7 +5615,7 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        loceol = scan + max;
     switch (OP(p)) {
     case REG_ANY:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            while (scan < loceol && hardcount < max && *scan != '\n') {
                scan += UTF8SKIP(scan);
@@ -4706,7 +5627,7 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        }
        break;
     case SANY:
-        if (do_utf8) {
+        if (utf8_target) {
            loceol = PL_regeol;
            while (scan < loceol && hardcount < max) {
                scan += UTF8SKIP(scan);
@@ -4738,10 +5659,10 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
            scan++;
        break;
     case ANYOF:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            while (hardcount < max && scan < loceol &&
-                  reginclass(prog, p, (U8*)scan, 0, do_utf8)) {
+                  reginclass(prog, p, (U8*)scan, 0, utf8_target)) {
                scan += UTF8SKIP(scan);
                hardcount++;
            }
@@ -4751,11 +5672,11 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        }
        break;
     case ALNUM:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            LOAD_UTF8_CHARCLASS_ALNUM();
            while (hardcount < max && scan < loceol &&
-                  swash_fetch(PL_utf8_alnum, (U8*)scan, do_utf8)) {
+                  swash_fetch(PL_utf8_alnum, (U8*)scan, utf8_target)) {
                scan += UTF8SKIP(scan);
                hardcount++;
            }
@@ -4766,7 +5687,7 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        break;
     case ALNUML:
        PL_reg_flags |= RF_tainted;
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            while (hardcount < max && scan < loceol &&
                   isALNUM_LC_utf8((U8*)scan)) {
@@ -4779,11 +5700,11 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        }
        break;
     case NALNUM:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            LOAD_UTF8_CHARCLASS_ALNUM();
            while (hardcount < max && scan < loceol &&
-                  !swash_fetch(PL_utf8_alnum, (U8*)scan, do_utf8)) {
+                  !swash_fetch(PL_utf8_alnum, (U8*)scan, utf8_target)) {
                scan += UTF8SKIP(scan);
                hardcount++;
            }
@@ -4794,7 +5715,7 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        break;
     case NALNUML:
        PL_reg_flags |= RF_tainted;
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            while (hardcount < max && scan < loceol &&
                   !isALNUM_LC_utf8((U8*)scan)) {
@@ -4807,12 +5728,12 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        }
        break;
     case SPACE:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            LOAD_UTF8_CHARCLASS_SPACE();
            while (hardcount < max && scan < loceol &&
                   (*scan == ' ' ||
-                   swash_fetch(PL_utf8_space,(U8*)scan, do_utf8))) {
+                   swash_fetch(PL_utf8_space,(U8*)scan, utf8_target))) {
                scan += UTF8SKIP(scan);
                hardcount++;
            }
@@ -4823,7 +5744,7 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        break;
     case SPACEL:
        PL_reg_flags |= RF_tainted;
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            while (hardcount < max && scan < loceol &&
                   (*scan == ' ' || isSPACE_LC_utf8((U8*)scan))) {
@@ -4836,23 +5757,23 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        }
        break;
     case NSPACE:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            LOAD_UTF8_CHARCLASS_SPACE();
            while (hardcount < max && scan < loceol &&
                   !(*scan == ' ' ||
-                    swash_fetch(PL_utf8_space,(U8*)scan, do_utf8))) {
+                    swash_fetch(PL_utf8_space,(U8*)scan, utf8_target))) {
                scan += UTF8SKIP(scan);
                hardcount++;
            }
        } else {
            while (scan < loceol && !isSPACE(*scan))
                scan++;
-           break;
        }
+       break;
     case NSPACEL:
        PL_reg_flags |= RF_tainted;
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            while (hardcount < max && scan < loceol &&
                   !(*scan == ' ' || isSPACE_LC_utf8((U8*)scan))) {
@@ -4865,11 +5786,11 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        }
        break;
     case DIGIT:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            LOAD_UTF8_CHARCLASS_DIGIT();
            while (hardcount < max && scan < loceol &&
-                  swash_fetch(PL_utf8_digit, (U8*)scan, do_utf8)) {
+                  swash_fetch(PL_utf8_digit, (U8*)scan, utf8_target)) {
                scan += UTF8SKIP(scan);
                hardcount++;
            }
@@ -4879,11 +5800,11 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
        }
        break;
     case NDIGIT:
-       if (do_utf8) {
+       if (utf8_target) {
            loceol = PL_regeol;
            LOAD_UTF8_CHARCLASS_DIGIT();
            while (hardcount < max && scan < loceol &&
-                  !swash_fetch(PL_utf8_digit, (U8*)scan, do_utf8)) {
+                  !swash_fetch(PL_utf8_digit, (U8*)scan, utf8_target)) {
                scan += UTF8SKIP(scan);
                hardcount++;
            }
@@ -4891,7 +5812,77 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
            while (scan < loceol && !isDIGIT(*scan))
                scan++;
        }
+    case LNBREAK:
+        if (utf8_target) {
+           loceol = PL_regeol;
+           while (hardcount < max && scan < loceol && (c=is_LNBREAK_utf8(scan))) {
+               scan += c;
+               hardcount++;
+           }
+       } else {
+           /*
+             LNBREAK can match two latin chars, which is ok,
+             because we have a null terminated string, but we
+             have to use hardcount in this situation
+           */
+           while (scan < loceol && (c=is_LNBREAK_latin1(scan)))  {
+               scan+=c;
+               hardcount++;
+           }
+       }       
+       break;
+    case HORIZWS:
+        if (utf8_target) {
+           loceol = PL_regeol;
+           while (hardcount < max && scan < loceol && (c=is_HORIZWS_utf8(scan))) {
+               scan += c;
+               hardcount++;
+           }
+       } else {
+           while (scan < loceol && is_HORIZWS_latin1(scan)) 
+               scan++;         
+       }       
+       break;
+    case NHORIZWS:
+        if (utf8_target) {
+           loceol = PL_regeol;
+           while (hardcount < max && scan < loceol && !is_HORIZWS_utf8(scan)) {
+               scan += UTF8SKIP(scan);
+               hardcount++;
+           }
+       } else {
+           while (scan < loceol && !is_HORIZWS_latin1(scan))
+               scan++;
+
+       }       
+       break;
+    case VERTWS:
+        if (utf8_target) {
+           loceol = PL_regeol;
+           while (hardcount < max && scan < loceol && (c=is_VERTWS_utf8(scan))) {
+               scan += c;
+               hardcount++;
+           }
+       } else {
+           while (scan < loceol && is_VERTWS_latin1(scan)) 
+               scan++;
+
+       }       
+       break;
+    case NVERTWS:
+        if (utf8_target) {
+           loceol = PL_regeol;
+           while (hardcount < max && scan < loceol && !is_VERTWS_utf8(scan)) {
+               scan += UTF8SKIP(scan);
+               hardcount++;
+           }
+       } else {
+           while (scan < loceol && !is_VERTWS_latin1(scan)) 
+               scan++;
+          
+       }       
        break;
+
     default:           /* Called on something of 0 width. */
        break;          /* So match right here or not at all. */
     }
@@ -4903,22 +5894,21 @@ S_regrepeat(pTHX_ const regexp *prog, const regnode *p, I32 max)
     PL_reginput = scan;
 
     DEBUG_r({
-               SV *re_debug_flags = NULL;
-               SV * const prop = sv_newmortal();
-                GET_RE_DEBUG_FLAGS;
-                DEBUG_EXECUTE_r({
-               regprop(prog, prop, p);
-               PerlIO_printf(Perl_debug_log,
-                             "%*s  %s can match %"IVdf" times out of %"IVdf"...\n",
-                             REPORT_CODE_OFF+1, "", SvPVX_const(prop),(IV)c,(IV)max);
-       });
+       GET_RE_DEBUG_FLAGS_DECL;
+       DEBUG_EXECUTE_r({
+           SV * const prop = sv_newmortal();
+           regprop(prog, prop, p);
+           PerlIO_printf(Perl_debug_log,
+                       "%*s  %s can match %"IVdf" times out of %"IVdf"...\n",
+                       REPORT_CODE_OFF + depth*2, "", SvPVX_const(prop),(IV)c,(IV)max);
        });
+    });
 
     return(c);
 }
 
 
-#ifndef PERL_IN_XSUB_RE
+#if !defined(PERL_IN_XSUB_RE) || defined(PLUGGABLE_RE_EXTENSION)
 /*
 - regclass_swash - prepare the utf8 swash
 */
@@ -4930,14 +5920,17 @@ Perl_regclass_swash(pTHX_ const regexp *prog, register const regnode* node, bool
     SV *sw  = NULL;
     SV *si  = NULL;
     SV *alt = NULL;
-    const struct reg_data *data = prog ? prog->data : NULL;
+    RXi_GET_DECL(prog,progi);
+    const struct reg_data * const data = prog ? progi->data : NULL;
+
+    PERL_ARGS_ASSERT_REGCLASS_SWASH;
 
     if (data && data->count) {
        const U32 n = ARG(node);
 
        if (data->what[n] == 's') {
-           SV * const rv = (SV*)data->data[n];
-           AV * const av = (AV*)SvRV((SV*)rv);
+           SV * const rv = MUTABLE_SV(data->data[n]);
+           AV * const av = MUTABLE_AV(SvRV(rv));
            SV **const ary = AvARRAY(av);
            SV **a, **b;
        
@@ -4945,8 +5938,8 @@ Perl_regclass_swash(pTHX_ const regexp *prog, register const regnode* node, bool
             * documentation of these array elements. */
 
            si = *ary;
-           a  = SvROK(ary[1]) ? &ary[1] : 0;
-           b  = SvTYPE(ary[2]) == SVt_PVAV ? &ary[2] : 0;
+           a  = SvROK(ary[1]) ? &ary[1] : NULL;
+           b  = SvTYPE(ary[2]) == SVt_PVAV ? &ary[2] : NULL;
 
            if (a)
                sw = *a;
@@ -4974,12 +5967,12 @@ Perl_regclass_swash(pTHX_ const regexp *prog, register const regnode* node, bool
   The n is the ANYOF regnode, the p is the target string, lenp
   is pointer to the maximum length of how far to go in the p
   (if the lenp is zero, UTF8SKIP(p) is used),
-  do_utf8 tells whether the target string is in UTF-8.
+  utf8_target tells whether the target string is in UTF-8.
 
  */
 
 STATIC bool
-S_reginclass(pTHX_ const regexp *prog, register const regnode *n, register const U8* p, STRLEN* lenp, register bool do_utf8)
+S_reginclass(pTHX_ const regexp *prog, register const regnode *n, register const U8* p, STRLEN* lenp, register bool utf8_target)
 {
     dVAR;
     const char flags = ANYOF_FLAGS(n);
@@ -4988,30 +5981,41 @@ S_reginclass(pTHX_ const regexp *prog, register const regnode *n, register const
     STRLEN len = 0;
     STRLEN plen;
 
-    if (do_utf8 && !UTF8_IS_INVARIANT(c)) {
+    PERL_ARGS_ASSERT_REGINCLASS;
+
+    if (utf8_target && !UTF8_IS_INVARIANT(c)) {
        c = utf8n_to_uvchr(p, UTF8_MAXBYTES, &len,
-               (UTF8_ALLOW_DEFAULT & UTF8_ALLOW_ANYUV) | UTF8_CHECK_ONLY);
-               /* see [perl #37836] for UTF8_ALLOW_ANYUV */
-       if (len == (STRLEN)-1)
+               (UTF8_ALLOW_DEFAULT & UTF8_ALLOW_ANYUV)
+               | UTF8_ALLOW_FFFF | UTF8_CHECK_ONLY);
+               /* see [perl #37836] for UTF8_ALLOW_ANYUV; [perl #38293] for
+                * UTF8_ALLOW_FFFF */
+       if (len == (STRLEN)-1) 
            Perl_croak(aTHX_ "Malformed UTF-8 character (fatal)");
     }
 
     plen = lenp ? *lenp : UNISKIP(NATIVE_TO_UNI(c));
-    if (do_utf8 || (flags & ANYOF_UNICODE)) {
+    if (utf8_target || (flags & ANYOF_UNICODE)) {
         if (lenp)
            *lenp = 0;
-       if (do_utf8 && !ANYOF_RUNTIME(n)) {
+       if (utf8_target && !ANYOF_RUNTIME(n)) {
            if (len != (STRLEN)-1 && c < 256 && ANYOF_BITMAP_TEST(n, c))
                match = TRUE;
        }
-       if (!match && do_utf8 && (flags & ANYOF_UNICODE_ALL) && c >= 256)
+       if (!match && utf8_target && (flags & ANYOF_UNICODE_ALL) && c >= 256)
            match = TRUE;
        if (!match) {
            AV *av;
            SV * const sw = regclass_swash(prog, n, TRUE, 0, (SV**)&av);
        
            if (sw) {
-               if (swash_fetch(sw, p, do_utf8))
+               U8 * utf8_p;
+               if (utf8_target) {
+                   utf8_p = (U8 *) p;
+               } else {
+                   STRLEN len = 1;
+                   utf8_p = bytes_to_utf8(p, &len);
+               }
+               if (swash_fetch(sw, utf8_p, 1))
                    match = TRUE;
                else if (flags & ANYOF_FOLD) {
                    if (!match && lenp && av) {
@@ -5020,8 +6024,7 @@ S_reginclass(pTHX_ const regexp *prog, register const regnode *n, register const
                            SV* const sv = *av_fetch(av, i, FALSE);
                            STRLEN len;
                            const char * const s = SvPV_const(sv, len);
-                       
-                           if (len <= plen && memEQ(s, (char*)p, len)) {
+                           if (len <= plen && memEQ(s, (char*)utf8_p, len)) {
                                *lenp = len;
                                match = TRUE;
                                break;
@@ -5030,13 +6033,16 @@ S_reginclass(pTHX_ const regexp *prog, register const regnode *n, register const
                    }
                    if (!match) {
                        U8 tmpbuf[UTF8_MAXBYTES_CASE+1];
-                       STRLEN tmplen;
 
-                       to_utf8_fold(p, tmpbuf, &tmplen);
-                       if (swash_fetch(sw, tmpbuf, do_utf8))
+                       STRLEN tmplen;
+                       to_utf8_fold(utf8_p, tmpbuf, &tmplen);
+                       if (swash_fetch(sw, tmpbuf, 1))
                            match = TRUE;
                    }
                }
+
+               /* If we allocated a string above, free it */
+               if (! utf8_target) Safefree(utf8_p);
            }
        }
        if (match && lenp && *lenp == 0)
@@ -5102,9 +6108,12 @@ S_reginclass(pTHX_ const regexp *prog, register const regnode *n, register const
 }
 
 STATIC U8 *
-S_reghop3(U8 *s, I32 off, U8* lim)
+S_reghop3(U8 *s, I32 off, const U8* lim)
 {
     dVAR;
+
+    PERL_ARGS_ASSERT_REGHOP3;
+
     if (off >= 0) {
        while (off-- && s < lim) {
            /* XXX could check well-formedness here */
@@ -5112,47 +6121,76 @@ S_reghop3(U8 *s, I32 off, U8* lim)
        }
     }
     else {
-       while (off++) {
-           if (s > lim) {
-               s--;
-               if (UTF8_IS_CONTINUED(*s)) {
-                   while (s > (U8*)lim && UTF8_IS_CONTINUATION(*s))
-                       s--;
-               }
-               /* XXX could check well-formedness here */
+        while (off++ && s > lim) {
+            s--;
+            if (UTF8_IS_CONTINUED(*s)) {
+                while (s > lim && UTF8_IS_CONTINUATION(*s))
+                    s--;
            }
+            /* XXX could check well-formedness here */
        }
     }
     return s;
 }
 
+#ifdef XXX_dmq
+/* there are a bunch of places where we use two reghop3's that should
+   be replaced with this routine. but since thats not done yet 
+   we ifdef it out - dmq
+*/
+STATIC U8 *
+S_reghop4(U8 *s, I32 off, const U8* llim, const U8* rlim)
+{
+    dVAR;
+
+    PERL_ARGS_ASSERT_REGHOP4;
+
+    if (off >= 0) {
+        while (off-- && s < rlim) {
+            /* XXX could check well-formedness here */
+            s += UTF8SKIP(s);
+        }
+    }
+    else {
+        while (off++ && s > llim) {
+            s--;
+            if (UTF8_IS_CONTINUED(*s)) {
+                while (s > llim && UTF8_IS_CONTINUATION(*s))
+                    s--;
+            }
+            /* XXX could check well-formedness here */
+        }
+    }
+    return s;
+}
+#endif
+
 STATIC U8 *
-S_reghopmaybe3(U8* s, I32 off, U8* lim)
+S_reghopmaybe3(U8* s, I32 off, const U8* lim)
 {
     dVAR;
+
+    PERL_ARGS_ASSERT_REGHOPMAYBE3;
+
     if (off >= 0) {
        while (off-- && s < lim) {
            /* XXX could check well-formedness here */
            s += UTF8SKIP(s);
        }
        if (off >= 0)
-           return 0;
+           return NULL;
     }
     else {
-       while (off++) {
-           if (s > lim) {
-               s--;
-               if (UTF8_IS_CONTINUED(*s)) {
-                   while (s > (U8*)lim && UTF8_IS_CONTINUATION(*s))
-                       s--;
-               }
-               /* XXX could check well-formedness here */
+        while (off++ && s > lim) {
+            s--;
+            if (UTF8_IS_CONTINUED(*s)) {
+                while (s > lim && UTF8_IS_CONTINUATION(*s))
+                    s--;
            }
-           else
-               break;
+            /* XXX could check well-formedness here */
        }
        if (off <= 0)
-           return 0;
+           return NULL;
     }
     return s;
 }
@@ -5169,7 +6207,7 @@ restore_pos(pTHX_ void *arg)
 #ifdef PERL_OLD_COPY_ON_WRITE
            rex->saved_copy = PL_nrs;
 #endif
-           RX_MATCH_COPIED_on(rex);
+           RXp_MATCH_COPIED_on(rex);
        }
        PL_reg_magic->mg_len = PL_reg_oldpos;
        PL_reg_eval_set = 0;
@@ -5180,56 +6218,66 @@ restore_pos(pTHX_ void *arg)
 STATIC void
 S_to_utf8_substr(pTHX_ register regexp *prog)
 {
-    if (prog->float_substr && !prog->float_utf8) {
-       SV* const sv = newSVsv(prog->float_substr);
-       prog->float_utf8 = sv;
-       sv_utf8_upgrade(sv);
-       if (SvTAIL(prog->float_substr))
-           SvTAIL_on(sv);
-       if (prog->float_substr == prog->check_substr)
-           prog->check_utf8 = sv;
-    }
-    if (prog->anchored_substr && !prog->anchored_utf8) {
-       SV* const sv = newSVsv(prog->anchored_substr);
-       prog->anchored_utf8 = sv;
-       sv_utf8_upgrade(sv);
-       if (SvTAIL(prog->anchored_substr))
-           SvTAIL_on(sv);
-       if (prog->anchored_substr == prog->check_substr)
-           prog->check_utf8 = sv;
-    }
+    int i = 1;
+
+    PERL_ARGS_ASSERT_TO_UTF8_SUBSTR;
+
+    do {
+       if (prog->substrs->data[i].substr
+           && !prog->substrs->data[i].utf8_substr) {
+           SV* const sv = newSVsv(prog->substrs->data[i].substr);
+           prog->substrs->data[i].utf8_substr = sv;
+           sv_utf8_upgrade(sv);
+           if (SvVALID(prog->substrs->data[i].substr)) {
+               const U8 flags = BmFLAGS(prog->substrs->data[i].substr);
+               if (flags & FBMcf_TAIL) {
+                   /* Trim the trailing \n that fbm_compile added last
+                      time.  */
+                   SvCUR_set(sv, SvCUR(sv) - 1);
+                   /* Whilst this makes the SV technically "invalid" (as its
+                      buffer is no longer followed by "\0") when fbm_compile()
+                      adds the "\n" back, a "\0" is restored.  */
+               }
+               fbm_compile(sv, flags);
+           }
+           if (prog->substrs->data[i].substr == prog->check_substr)
+               prog->check_utf8 = sv;
+       }
+    } while (i--);
 }
 
 STATIC void
 S_to_byte_substr(pTHX_ register regexp *prog)
 {
     dVAR;
-    if (prog->float_utf8 && !prog->float_substr) {
-       SV* sv = newSVsv(prog->float_utf8);
-       prog->float_substr = sv;
-       if (sv_utf8_downgrade(sv, TRUE)) {
-           if (SvTAIL(prog->float_utf8))
-               SvTAIL_on(sv);
-       } else {
-           SvREFCNT_dec(sv);
-           prog->float_substr = sv = &PL_sv_undef;
-       }
-       if (prog->float_utf8 == prog->check_utf8)
-           prog->check_substr = sv;
-    }
-    if (prog->anchored_utf8 && !prog->anchored_substr) {
-       SV* sv = newSVsv(prog->anchored_utf8);
-       prog->anchored_substr = sv;
-       if (sv_utf8_downgrade(sv, TRUE)) {
-           if (SvTAIL(prog->anchored_utf8))
-               SvTAIL_on(sv);
-       } else {
-           SvREFCNT_dec(sv);
-           prog->anchored_substr = sv = &PL_sv_undef;
+    int i = 1;
+
+    PERL_ARGS_ASSERT_TO_BYTE_SUBSTR;
+
+    do {
+       if (prog->substrs->data[i].utf8_substr
+           && !prog->substrs->data[i].substr) {
+           SV* sv = newSVsv(prog->substrs->data[i].utf8_substr);
+           if (sv_utf8_downgrade(sv, TRUE)) {
+               if (SvVALID(prog->substrs->data[i].utf8_substr)) {
+                   const U8 flags
+                       = BmFLAGS(prog->substrs->data[i].utf8_substr);
+                   if (flags & FBMcf_TAIL) {
+                       /* Trim the trailing \n that fbm_compile added last
+                          time.  */
+                       SvCUR_set(sv, SvCUR(sv) - 1);
+                   }
+                   fbm_compile(sv, flags);
+               }           
+           } else {
+               SvREFCNT_dec(sv);
+               sv = &PL_sv_undef;
+           }
+           prog->substrs->data[i].substr = sv;
+           if (prog->substrs->data[i].utf8_substr == prog->check_utf8)
+               prog->check_substr = sv;
        }
-       if (prog->anchored_utf8 == prog->check_utf8)
-           prog->check_substr = sv;
-    }
+    } while (i--);
 }
 
 /*