From: Rafael Garcia-Suarez <rgarciasuarez@gmail.com>
Date: Wed, 9 Mar 2005 22:17:33 +0000 (+0000)
Subject: Further pack optimisations by Ton Hospel
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=3473cf637176ce9e9e990cc9b108dfc4974b52c4;p=p5sagit%2Fp5-mst-13.2.git
Further pack optimisations by Ton Hospel
p4raw-id: //depot/perl@24012
---
diff --git a/pp_pack.c b/pp_pack.c
index 6c9b92a..204b17c 100644
--- a/pp_pack.c
+++ b/pp_pack.c
@@ -39,6 +39,8 @@
#ifndef CHAR_BIT
# define CHAR_BIT 8
#endif
+/* Maximum number of bytes to which a byte can grow due to upgrade */
+#define UTF8_EXPAND 2
/*
* Offset for integer pack/unpack.
@@ -648,7 +650,7 @@ STMT_START { \
#define GROWING(utf8, cat, start, cur, in_len) \
STMT_START { \
STRLEN glen = (in_len); \
- if (utf8) glen *= 2; \
+ if (utf8) glen *= UTF8_EXPAND; \
if ((cur) + glen >= (start) + SvLEN(cat)) { \
(start) = sv_exp_grow(aTHX_ cat, glen); \
(cur) = (start) + SvCUR(cat); \
@@ -659,7 +661,7 @@ STMT_START { \
STMT_START { \
STRLEN glen = (in_len); \
STRLEN gl = glen; \
- if (utf8) gl *= 2; \
+ if (utf8) gl *= UTF8_EXPAND; \
if ((cur) + gl >= (start) + SvLEN(cat)) { \
*cur = '\0'; \
SvCUR(cat) = (cur) - (start); \
@@ -2335,8 +2337,7 @@ marked_upgrade(pTHX_ SV *sv, tempsym_t *sym_ptr) {
return;
}
- /* We assume a char translates to at most 2 UTF-8 bytes */
- len = (from_end-from_ptr)*2+(from_ptr-from_start)+1;
+ len = (from_end-from_ptr)*UTF8_EXPAND+(from_ptr-from_start)+1;
New('U', to_start, len, char);
Copy(from_start, to_start, from_ptr-from_start, char);
to_ptr = to_start + (from_ptr-from_start);
@@ -2643,9 +2644,10 @@ S_pack_rec(pTHX_ SV *cat, tempsym_t* symptr, SV **beglist, SV **endlist )
fromlen = len;
if (datumtype == 'Z' && fromlen > 0) fromlen--;
}
- /* assumes a byte expands to at most 2 bytes on upgrade:
- expected_length <= from_len*2 + (len-from_len) */
- GROWING(0, cat, start, cur, fromlen+len);
+ /* assumes a byte expands to at most UTF8_EXPAND bytes on
+ upgrade, so:
+ expected_length <= from_len*UTF8_EXPAND + (len-from_len) */
+ GROWING(0, cat, start, cur, fromlen*(UTF8_EXPAND-1)+len);
len -= fromlen;
while (fromlen > 0) {
cur = uvchr_to_utf8(cur, * (U8 *) aptr);
@@ -2921,11 +2923,12 @@ S_pack_rec(pTHX_ SV *cat, tempsym_t* symptr, SV **beglist, SV **endlist )
endb = uvuni_to_utf8_flags(buffer, auv,
ckWARN(WARN_UTF8) ?
0 : UNICODE_ALLOW_ANY);
- if (cur >= end-(endb-buffer)*2) {
+ if (cur+(endb-buffer)*UTF8_EXPAND >= end) {
*cur = '\0';
SvCUR(cat) = cur - start;
- GROWING(0, cat, start, cur, len+(endb-buffer)*2);
- end = start+SvLEN(cat)-UTF8_MAXLEN;
+ GROWING(0, cat, start, cur,
+ len+(endb-buffer)*UTF8_EXPAND);
+ end = start+SvLEN(cat);
}
bytes_to_uni(aTHX_ buffer, endb-buffer, &cur);
} else {