/* numeric.c
*
- * Copyright (c) 2001, Larry Wall
+ * Copyright (c) 2001-2002, Larry Wall
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
* wizards count differently to other people."
*/
+/*
+=head1 Numeric functions
+*/
+
#include "EXTERN.h"
#define PERL_IN_NUMERIC_C
#include "perl.h"
}
#endif
-NV
-Perl_scan_bin(pTHX_ char *start, STRLEN len, STRLEN *retlen)
-{
- register char *s = start;
- register NV rnv = 0.0;
- register UV ruv = 0;
- register bool seenb = FALSE;
- register bool overflowed = FALSE;
+/*
+=for apidoc grok_bin
+
+converts a string representing a binary number to numeric form.
+
+On entry I<start> and I<*len> give the string to scan, I<*flags> gives
+conversion flags, and I<result> should be NULL or a pointer to an NV.
+The scan stops at the end of the string, or the first invalid character.
+On return I<*len> is set to the length scanned string, and I<*flags> gives
+output flags.
+
+If the value is <= UV_MAX it is returned as a UV, the output flags are clear,
+and nothing is written to I<*result>. If the value is > UV_MAX C<grok_bin>
+returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
+and writes the value to I<*result> (or the value is discarded if I<result>
+is NULL).
+
+The hex number may optionally be prefixed with "0b" or "b" unless
+C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If
+C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the binary
+number may use '_' characters to separate digits.
+
+=cut
+ */
+
+UV
+Perl_grok_bin(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) {
+ const char *s = start;
+ STRLEN len = *len_p;
+ UV value = 0;
+ NV value_nv = 0;
+
+ const UV max_div_2 = UV_MAX / 2;
+ bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES;
+ bool overflowed = FALSE;
+
+ if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) {
+ /* strip off leading b or 0b.
+ for compatibility silently suffer "b" and "0b" as valid binary
+ numbers. */
+ if (len >= 1) {
+ if (s[0] == 'b') {
+ s++;
+ len--;
+ }
+ else if (len >= 2 && s[0] == '0' && s[1] == 'b') {
+ s+=2;
+ len-=2;
+ }
+ }
+ }
for (; len-- && *s; s++) {
- if (!(*s == '0' || *s == '1')) {
- if (*s == '_' && len && *retlen
- && (s[1] == '0' || s[1] == '1'))
- {
- --len;
- ++s;
- }
- else if (seenb == FALSE && *s == 'b' && ruv == 0) {
- /* Disallow 0bbb0b0bbb... */
- seenb = TRUE;
- continue;
- }
- else {
- if (ckWARN(WARN_DIGIT))
- Perl_warner(aTHX_ WARN_DIGIT,
- "Illegal binary digit '%c' ignored", *s);
- break;
- }
- }
- if (!overflowed) {
- register UV xuv = ruv << 1;
-
- if ((xuv >> 1) != ruv) {
- overflowed = TRUE;
- rnv = (NV) ruv;
- if (ckWARN_d(WARN_OVERFLOW))
- Perl_warner(aTHX_ WARN_OVERFLOW,
- "Integer overflow in binary number");
- }
- else
- ruv = xuv | (*s - '0');
- }
- if (overflowed) {
- rnv *= 2;
+ char bit = *s;
+ if (bit == '0' || bit == '1') {
+ /* Write it in this wonky order with a goto to attempt to get the
+ compiler to make the common case integer-only loop pretty tight.
+ With gcc seems to be much straighter code than old scan_bin. */
+ redo:
+ if (!overflowed) {
+ if (value <= max_div_2) {
+ value = (value << 1) | (bit - '0');
+ continue;
+ }
+ /* Bah. We're just overflowed. */
+ if (ckWARN_d(WARN_OVERFLOW))
+ Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
+ "Integer overflow in binary number");
+ overflowed = TRUE;
+ value_nv = (NV) value;
+ }
+ value_nv *= 2.0;
/* If an NV has not enough bits in its mantissa to
- * represent an UV this summing of small low-order numbers
+ * represent a UV this summing of small low-order numbers
* is a waste of time (because the NV cannot preserve
* the low-order bits anyway): we could just remember when
- * did we overflow and in the end just multiply rnv by the
+ * did we overflow and in the end just multiply value_nv by the
* right amount. */
- rnv += (*s - '0');
- }
+ value_nv += (NV)(bit - '0');
+ continue;
+ }
+ if (bit == '_' && len && allow_underscores && (bit = s[1])
+ && (bit == '0' || bit == '1'))
+ {
+ --len;
+ ++s;
+ goto redo;
+ }
+ if (ckWARN(WARN_DIGIT))
+ Perl_warner(aTHX_ packWARN(WARN_DIGIT),
+ "Illegal binary digit '%c' ignored", *s);
+ break;
}
- if (!overflowed)
- rnv = (NV) ruv;
- if ( ( overflowed && rnv > 4294967295.0)
+
+ if ( ( overflowed && value_nv > 4294967295.0)
#if UVSIZE > 4
- || (!overflowed && ruv > 0xffffffff )
+ || (!overflowed && value > 0xffffffff )
#endif
) {
if (ckWARN(WARN_PORTABLE))
- Perl_warner(aTHX_ WARN_PORTABLE,
+ Perl_warner(aTHX_ packWARN(WARN_PORTABLE),
"Binary number > 0b11111111111111111111111111111111 non-portable");
}
- *retlen = s - start;
- return rnv;
+ *len_p = s - start;
+ if (!overflowed) {
+ *flags = 0;
+ return value;
+ }
+ *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
+ if (result)
+ *result = value_nv;
+ return UV_MAX;
}
-NV
-Perl_scan_oct(pTHX_ char *start, STRLEN len, STRLEN *retlen)
-{
- register char *s = start;
- register NV rnv = 0.0;
- register UV ruv = 0;
- register bool overflowed = FALSE;
+/*
+=for apidoc grok_hex
+
+converts a string representing a hex number to numeric form.
+
+On entry I<start> and I<*len> give the string to scan, I<*flags> gives
+conversion flags, and I<result> should be NULL or a pointer to an NV.
+The scan stops at the end of the string, or the first non-hex-digit character.
+On return I<*len> is set to the length scanned string, and I<*flags> gives
+output flags.
+
+If the value is <= UV_MAX it is returned as a UV, the output flags are clear,
+and nothing is written to I<*result>. If the value is > UV_MAX C<grok_hex>
+returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
+and writes the value to I<*result> (or the value is discarded if I<result>
+is NULL).
+
+The hex number may optionally be prefixed with "0x" or "x" unless
+C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If
+C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the hex
+number may use '_' characters to separate digits.
+
+=cut
+ */
+
+UV
+Perl_grok_hex(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) {
+ const char *s = start;
+ STRLEN len = *len_p;
+ UV value = 0;
+ NV value_nv = 0;
+
+ const UV max_div_16 = UV_MAX / 16;
+ bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES;
+ bool overflowed = FALSE;
+ const char *hexdigit;
+
+ if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) {
+ /* strip off leading x or 0x.
+ for compatibility silently suffer "x" and "0x" as valid hex numbers.
+ */
+ if (len >= 1) {
+ if (s[0] == 'x') {
+ s++;
+ len--;
+ }
+ else if (len >= 2 && s[0] == '0' && s[1] == 'x') {
+ s+=2;
+ len-=2;
+ }
+ }
+ }
for (; len-- && *s; s++) {
- if (!(*s >= '0' && *s <= '7')) {
- if (*s == '_' && len && *retlen
- && (s[1] >= '0' && s[1] <= '7'))
+ hexdigit = strchr((char *) PL_hexdigit, *s);
+ if (hexdigit) {
+ /* Write it in this wonky order with a goto to attempt to get the
+ compiler to make the common case integer-only loop pretty tight.
+ With gcc seems to be much straighter code than old scan_hex. */
+ redo:
+ if (!overflowed) {
+ if (value <= max_div_16) {
+ value = (value << 4) | ((hexdigit - PL_hexdigit) & 15);
+ continue;
+ }
+ /* Bah. We're just overflowed. */
+ if (ckWARN_d(WARN_OVERFLOW))
+ Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
+ "Integer overflow in hexadecimal number");
+ overflowed = TRUE;
+ value_nv = (NV) value;
+ }
+ value_nv *= 16.0;
+ /* If an NV has not enough bits in its mantissa to
+ * represent a UV this summing of small low-order numbers
+ * is a waste of time (because the NV cannot preserve
+ * the low-order bits anyway): we could just remember when
+ * did we overflow and in the end just multiply value_nv by the
+ * right amount of 16-tuples. */
+ value_nv += (NV)((hexdigit - PL_hexdigit) & 15);
+ continue;
+ }
+ if (*s == '_' && len && allow_underscores && s[1]
+ && (hexdigit = strchr((char *) PL_hexdigit, s[1])))
{
--len;
++s;
+ goto redo;
}
- else {
- /* Allow \octal to work the DWIM way (that is, stop scanning
- * as soon as non-octal characters are seen, complain only iff
- * someone seems to want to use the digits eight and nine). */
- if (*s == '8' || *s == '9') {
- if (ckWARN(WARN_DIGIT))
- Perl_warner(aTHX_ WARN_DIGIT,
- "Illegal octal digit '%c' ignored", *s);
- }
- break;
- }
- }
- if (!overflowed) {
- register UV xuv = ruv << 3;
-
- if ((xuv >> 3) != ruv) {
- overflowed = TRUE;
- rnv = (NV) ruv;
- if (ckWARN_d(WARN_OVERFLOW))
- Perl_warner(aTHX_ WARN_OVERFLOW,
- "Integer overflow in octal number");
- }
- else
- ruv = xuv | (*s - '0');
- }
- if (overflowed) {
- rnv *= 8.0;
- /* If an NV has not enough bits in its mantissa to
- * represent an UV this summing of small low-order numbers
- * is a waste of time (because the NV cannot preserve
- * the low-order bits anyway): we could just remember when
- * did we overflow and in the end just multiply rnv by the
- * right amount of 8-tuples. */
- rnv += (NV)(*s - '0');
- }
+ if (ckWARN(WARN_DIGIT))
+ Perl_warner(aTHX_ packWARN(WARN_DIGIT),
+ "Illegal hexadecimal digit '%c' ignored", *s);
+ break;
}
- if (!overflowed)
- rnv = (NV) ruv;
- if ( ( overflowed && rnv > 4294967295.0)
+
+ if ( ( overflowed && value_nv > 4294967295.0)
#if UVSIZE > 4
- || (!overflowed && ruv > 0xffffffff )
+ || (!overflowed && value > 0xffffffff )
#endif
) {
if (ckWARN(WARN_PORTABLE))
- Perl_warner(aTHX_ WARN_PORTABLE,
- "Octal number > 037777777777 non-portable");
+ Perl_warner(aTHX_ packWARN(WARN_PORTABLE),
+ "Hexadecimal number > 0xffffffff non-portable");
}
- *retlen = s - start;
- return rnv;
+ *len_p = s - start;
+ if (!overflowed) {
+ *flags = 0;
+ return value;
+ }
+ *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
+ if (result)
+ *result = value_nv;
+ return UV_MAX;
}
-NV
-Perl_scan_hex(pTHX_ char *start, STRLEN len, STRLEN *retlen)
-{
- register char *s = start;
- register NV rnv = 0.0;
- register UV ruv = 0;
- register bool overflowed = FALSE;
- char *hexdigit;
-
- if (len > 2) {
- if (s[0] == 'x') {
- s++;
- len--;
- }
- else if (len > 3 && s[0] == '0' && s[1] == 'x') {
- s+=2;
- len-=2;
- }
- }
+/*
+=for apidoc grok_oct
+
+
+=cut
+ */
+
+UV
+Perl_grok_oct(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) {
+ const char *s = start;
+ STRLEN len = *len_p;
+ UV value = 0;
+ NV value_nv = 0;
+
+ const UV max_div_8 = UV_MAX / 8;
+ bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES;
+ bool overflowed = FALSE;
for (; len-- && *s; s++) {
- hexdigit = strchr((char *) PL_hexdigit, *s);
- if (!hexdigit) {
- if (*s == '_' && len && *retlen && s[1]
- && (hexdigit = strchr((char *) PL_hexdigit, s[1])))
+ /* gcc 2.95 optimiser not smart enough to figure that this subtraction
+ out front allows slicker code. */
+ int digit = *s - '0';
+ if (digit >= 0 && digit <= 7) {
+ /* Write it in this wonky order with a goto to attempt to get the
+ compiler to make the common case integer-only loop pretty tight.
+ */
+ redo:
+ if (!overflowed) {
+ if (value <= max_div_8) {
+ value = (value << 3) | digit;
+ continue;
+ }
+ /* Bah. We're just overflowed. */
+ if (ckWARN_d(WARN_OVERFLOW))
+ Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
+ "Integer overflow in octal number");
+ overflowed = TRUE;
+ value_nv = (NV) value;
+ }
+ value_nv *= 8.0;
+ /* If an NV has not enough bits in its mantissa to
+ * represent a UV this summing of small low-order numbers
+ * is a waste of time (because the NV cannot preserve
+ * the low-order bits anyway): we could just remember when
+ * did we overflow and in the end just multiply value_nv by the
+ * right amount of 8-tuples. */
+ value_nv += (NV)digit;
+ continue;
+ }
+ if (digit == ('_' - '0') && len && allow_underscores
+ && (digit = s[1] - '0') && (digit >= 0 && digit <= 7))
{
--len;
++s;
+ goto redo;
}
- else {
- if (ckWARN(WARN_DIGIT))
- Perl_warner(aTHX_ WARN_DIGIT,
- "Illegal hexadecimal digit '%c' ignored", *s);
- break;
- }
- }
- if (!overflowed) {
- register UV xuv = ruv << 4;
-
- if ((xuv >> 4) != ruv) {
- overflowed = TRUE;
- rnv = (NV) ruv;
- if (ckWARN_d(WARN_OVERFLOW))
- Perl_warner(aTHX_ WARN_OVERFLOW,
- "Integer overflow in hexadecimal number");
- }
- else
- ruv = xuv | ((hexdigit - PL_hexdigit) & 15);
- }
- if (overflowed) {
- rnv *= 16.0;
- /* If an NV has not enough bits in its mantissa to
- * represent an UV this summing of small low-order numbers
- * is a waste of time (because the NV cannot preserve
- * the low-order bits anyway): we could just remember when
- * did we overflow and in the end just multiply rnv by the
- * right amount of 16-tuples. */
- rnv += (NV)((hexdigit - PL_hexdigit) & 15);
- }
+ /* Allow \octal to work the DWIM way (that is, stop scanning
+ * as soon as non-octal characters are seen, complain only iff
+ * someone seems to want to use the digits eight and nine). */
+ if (digit == 8 || digit == 9) {
+ if (ckWARN(WARN_DIGIT))
+ Perl_warner(aTHX_ packWARN(WARN_DIGIT),
+ "Illegal octal digit '%c' ignored", *s);
+ }
+ break;
}
- if (!overflowed)
- rnv = (NV) ruv;
- if ( ( overflowed && rnv > 4294967295.0)
+
+ if ( ( overflowed && value_nv > 4294967295.0)
#if UVSIZE > 4
- || (!overflowed && ruv > 0xffffffff )
+ || (!overflowed && value > 0xffffffff )
#endif
) {
if (ckWARN(WARN_PORTABLE))
- Perl_warner(aTHX_ WARN_PORTABLE,
- "Hexadecimal number > 0xffffffff non-portable");
+ Perl_warner(aTHX_ packWARN(WARN_PORTABLE),
+ "Octal number > 037777777777 non-portable");
+ }
+ *len_p = s - start;
+ if (!overflowed) {
+ *flags = 0;
+ return value;
}
- *retlen = s - start;
- return rnv;
+ *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
+ if (result)
+ *result = value_nv;
+ return UV_MAX;
+}
+
+/*
+=for apidoc scan_bin
+
+For backwards compatibility. Use C<grok_bin> instead.
+
+=for apidoc scan_hex
+
+For backwards compatibility. Use C<grok_hex> instead.
+
+=for apidoc scan_oct
+
+For backwards compatibility. Use C<grok_oct> instead.
+
+=cut
+ */
+
+NV
+Perl_scan_bin(pTHX_ char *start, STRLEN len, STRLEN *retlen)
+{
+ NV rnv;
+ I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
+ UV ruv = grok_bin (start, &len, &flags, &rnv);
+
+ *retlen = len;
+ return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
+}
+
+NV
+Perl_scan_oct(pTHX_ char *start, STRLEN len, STRLEN *retlen)
+{
+ NV rnv;
+ I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
+ UV ruv = grok_oct (start, &len, &flags, &rnv);
+
+ *retlen = len;
+ return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
+}
+
+NV
+Perl_scan_hex(pTHX_ char *start, STRLEN len, STRLEN *retlen)
+{
+ NV rnv;
+ I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
+ UV ruv = grok_hex (start, &len, &flags, &rnv);
+
+ *retlen = len;
+ return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
}
/*
Recognise (or not) a number. The type of the number is returned
(0 if unrecognised), otherwise it is a bit-ORed combination of
IS_NUMBER_IN_UV, IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT,
-IS_NUMBER_NEG, IS_NUMBER_INFINITY (defined in perl.h).
+IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h).
If the value of the number can fit an in UV, it is returned in the *valuep
IS_NUMBER_IN_UV will be set to indicate that *valuep is valid, IS_NUMBER_IN_UV
const char max_mod_10 = UV_MAX % 10;
int numtype = 0;
int sawinf = 0;
+ int sawnan = 0;
while (s < send && isSPACE(*s))
s++;
s++;
}
sawinf = 1;
- } else /* Add test for NaN here. */
+ } else if (*s == 'N' || *s == 'n') {
+ /* XXX TODO: There are signaling NaNs and quiet NaNs. */
+ s++; if (s == send || (*s != 'A' && *s != 'a')) return 0;
+ s++; if (s == send || (*s != 'N' && *s != 'n')) return 0;
+ s++;
+ sawnan = 1;
+ } else
return 0;
if (sawinf) {
numtype &= IS_NUMBER_NEG; /* Keep track of sign */
numtype |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT;
+ } else if (sawnan) {
+ numtype &= IS_NUMBER_NEG; /* Keep track of sign */
+ numtype |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
} else if (s < send) {
/* we can have an optional exponent part */
if (*s == 'e' || *s == 'E') {
while (s < send && isSPACE(*s))
s++;
if (s >= send)
- return numtype;
+ return numtype;
if (len == 10 && memEQ(pv, "0 but true", 10)) {
if (valuep)
*valuep = 0;
if (exponent == 0)
return value;
- else if (exponent < 0) {
+
+ /* On OpenVMS VAX we by default use the D_FLOAT double format,
+ * and that format does not have *easy* capabilities [1] for
+ * overflowing doubles 'silently' as IEEE fp does. We also need
+ * to support G_FLOAT on both VAX and Alpha, and though the exponent
+ * range is much larger than D_FLOAT it still doesn't do silent
+ * overflow. Therefore we need to detect early whether we would
+ * overflow (this is the behaviour of the native string-to-float
+ * conversion routines, and therefore of native applications, too).
+ *
+ * [1] Trying to establish a condition handler to trap floating point
+ * exceptions is not a good idea. */
+
+ /* In UNICOS and in certain Cray models (such as T90) there is no
+ * IEEE fp, and no way at all from C to catch fp overflows gracefully.
+ * There is something you can do if you are willing to use some
+ * inline assembler: the instruction is called DFI-- but that will
+ * disable *all* floating point interrupts, a little bit too large
+ * a hammer. Therefore we need to catch potential overflows before
+ * it's too late. */
+
+#if ((defined(VMS) && !defined(__IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP)
+ STMT_START {
+ NV exp_v = log10(value);
+ if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP)
+ return NV_MAX;
+ if (exponent < 0) {
+ if (-(exponent + exp_v) >= NV_MAX_10_EXP)
+ return 0.0;
+ while (-exponent >= NV_MAX_10_EXP) {
+ /* combination does not overflow, but 10^(-exponent) does */
+ value /= 10;
+ ++exponent;
+ }
+ }
+ } STMT_END;
+#endif
+
+ if (exponent < 0) {
negative = 1;
exponent = -exponent;
}
-#ifdef __VAX /* avoid %SYSTEM-F-FLTOVF_F sans VAXC$ESTABLISH */
-# if defined(__DECC_VER) && __DECC_VER <= 50390006
- /* __F_FLT_MAX_10_EXP - 5 == 33 */
- if (!negative &&
- (log10(value) + exponent) >= (__F_FLT_MAX_10_EXP - 5))
- return NV_MAX;
-# endif
-#endif
for (bit = 1; exponent; bit <<= 1) {
if (exponent & bit) {
exponent ^= bit;
result *= power;
+ /* Floating point exceptions are supposed to be turned off,
+ * but if we're obviously done, don't risk another iteration.
+ */
+ if (exponent == 0) break;
}
power *= power;
}
/* Scan the number twice; once using locale and once without;
* choose the larger result (in absolute value). */
- Perl_atof2(aTHX_ s, &x);
+ Perl_atof2(s, x);
SET_NUMERIC_STANDARD();
- Perl_atof2(aTHX_ s, &y);
+ Perl_atof2(s, y);
SET_NUMERIC_LOCAL();
if ((y < 0.0 && y < x) || (y > 0.0 && y > x))
return y;
}
else
- Perl_atof2(aTHX_ s, &x);
+ Perl_atof2(s, x);
#else
- Perl_atof2(aTHX_ s, &x);
+ Perl_atof2(s, x);
#endif
return x;
}
Perl_my_atof2(pTHX_ const char* orig, NV* value)
{
NV result = 0.0;
- bool negative = 0;
char* s = (char*)orig;
+#ifdef USE_PERL_ATOF
+ bool negative = 0;
char* send = s + strlen(orig) - 1;
bool seendigit = 0;
I32 expextra = 0;
/* now apply the sign */
if (negative)
result = -result;
+#endif /* USE_PERL_ATOF */
*value = result;
return s;
}