3 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
4 * 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * "That only makes eleven (plus one mislaid) and not fourteen,
13 * unless wizards count differently to other people." --Beorn
15 * [p.115 of _The Hobbit_: "Queer Lodgings"]
19 =head1 Numeric functions
23 This file contains all the stuff needed by perl for manipulating numeric
24 values, including such things as replacements for the OS's atof() function
29 #define PERL_IN_NUMERIC_C
36 return f < I32_MIN ? (U32) I32_MIN : (U32)(I32) f;
39 if (f < U32_MAX_P1_HALF)
42 return ((U32) f) | (1 + (U32_MAX >> 1));
47 return f > 0 ? U32_MAX : 0 /* NaN */;
54 return f < I32_MIN ? I32_MIN : (I32) f;
57 if (f < U32_MAX_P1_HALF)
60 return (I32)(((U32) f) | (1 + (U32_MAX >> 1)));
65 return f > 0 ? (I32)U32_MAX : 0 /* NaN */;
72 return f < IV_MIN ? IV_MIN : (IV) f;
75 /* For future flexibility allowing for sizeof(UV) >= sizeof(IV) */
76 if (f < UV_MAX_P1_HALF)
79 return (IV)(((UV) f) | (1 + (UV_MAX >> 1)));
84 return f > 0 ? (IV)UV_MAX : 0 /* NaN */;
91 return f < IV_MIN ? (UV) IV_MIN : (UV)(IV) f;
94 if (f < UV_MAX_P1_HALF)
97 return ((UV) f) | (1 + (UV_MAX >> 1));
102 return f > 0 ? UV_MAX : 0 /* NaN */;
108 converts a string representing a binary number to numeric form.
110 On entry C<start> and C<*len> give the string to scan, C<*flags> gives
111 conversion flags, and C<result> should be C<NULL> or a pointer to an NV.
112 The scan stops at the end of the string, or the first invalid character.
113 Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in C<*flags>, encountering an
114 invalid character will also trigger a warning.
115 On return C<*len> is set to the length of the scanned string,
116 and C<*flags> gives output flags.
118 If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
119 and nothing is written to C<*result>. If the value is > C<UV_MAX>, C<grok_bin>
120 returns C<UV_MAX>, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
121 and writes the value to C<*result> (or the value is discarded if C<result>
124 The binary number may optionally be prefixed with C<"0b"> or C<"b"> unless
125 C<PERL_SCAN_DISALLOW_PREFIX> is set in C<*flags> on entry. If
126 C<PERL_SCAN_ALLOW_UNDERSCORES> is set in C<*flags> then the binary
127 number may use C<"_"> characters to separate digits.
131 Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE
132 which suppresses any message for non-portable numbers that are still valid
137 Perl_grok_bin(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
139 const char *s = start;
144 const UV max_div_2 = UV_MAX / 2;
145 const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
146 bool overflowed = FALSE;
149 PERL_ARGS_ASSERT_GROK_BIN;
151 if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) {
152 /* strip off leading b or 0b.
153 for compatibility silently suffer "b" and "0b" as valid binary
156 if (isALPHA_FOLD_EQ(s[0], 'b')) {
160 else if (len >= 2 && s[0] == '0' && (isALPHA_FOLD_EQ(s[1], 'b'))) {
167 for (; len-- && (bit = *s); s++) {
168 if (bit == '0' || bit == '1') {
169 /* Write it in this wonky order with a goto to attempt to get the
170 compiler to make the common case integer-only loop pretty tight.
171 With gcc seems to be much straighter code than old scan_bin. */
174 if (value <= max_div_2) {
175 value = (value << 1) | (bit - '0');
178 /* Bah. We're just overflowed. */
179 /* diag_listed_as: Integer overflow in %s number */
180 Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW),
181 "Integer overflow in binary number");
183 value_nv = (NV) value;
186 /* If an NV has not enough bits in its mantissa to
187 * represent a UV this summing of small low-order numbers
188 * is a waste of time (because the NV cannot preserve
189 * the low-order bits anyway): we could just remember when
190 * did we overflow and in the end just multiply value_nv by the
192 value_nv += (NV)(bit - '0');
195 if (bit == '_' && len && allow_underscores && (bit = s[1])
196 && (bit == '0' || bit == '1'))
202 if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT))
203 Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT),
204 "Illegal binary digit '%c' ignored", *s);
208 if ( ( overflowed && value_nv > 4294967295.0)
210 || (!overflowed && value > 0xffffffff
211 && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE))
214 Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE),
215 "Binary number > 0b11111111111111111111111111111111 non-portable");
222 *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
231 converts a string representing a hex number to numeric form.
233 On entry C<start> and C<*len_p> give the string to scan, C<*flags> gives
234 conversion flags, and C<result> should be C<NULL> or a pointer to an NV.
235 The scan stops at the end of the string, or the first invalid character.
236 Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in C<*flags>, encountering an
237 invalid character will also trigger a warning.
238 On return C<*len> is set to the length of the scanned string,
239 and C<*flags> gives output flags.
241 If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
242 and nothing is written to C<*result>. If the value is > C<UV_MAX>, C<grok_hex>
243 returns C<UV_MAX>, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
244 and writes the value to C<*result> (or the value is discarded if C<result>
247 The hex number may optionally be prefixed with C<"0x"> or C<"x"> unless
248 C<PERL_SCAN_DISALLOW_PREFIX> is set in C<*flags> on entry. If
249 C<PERL_SCAN_ALLOW_UNDERSCORES> is set in C<*flags> then the hex
250 number may use C<"_"> characters to separate digits.
254 Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE
255 which suppresses any message for non-portable numbers, but which are valid
260 Perl_grok_hex(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
262 const char *s = start;
266 const UV max_div_16 = UV_MAX / 16;
267 const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
268 bool overflowed = FALSE;
270 PERL_ARGS_ASSERT_GROK_HEX;
272 if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) {
273 /* strip off leading x or 0x.
274 for compatibility silently suffer "x" and "0x" as valid hex numbers.
277 if (isALPHA_FOLD_EQ(s[0], 'x')) {
281 else if (len >= 2 && s[0] == '0' && (isALPHA_FOLD_EQ(s[1], 'x'))) {
288 for (; len-- && *s; s++) {
290 /* Write it in this wonky order with a goto to attempt to get the
291 compiler to make the common case integer-only loop pretty tight.
292 With gcc seems to be much straighter code than old scan_hex. */
295 if (value <= max_div_16) {
296 value = (value << 4) | XDIGIT_VALUE(*s);
299 /* Bah. We're just overflowed. */
300 /* diag_listed_as: Integer overflow in %s number */
301 Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW),
302 "Integer overflow in hexadecimal number");
304 value_nv = (NV) value;
307 /* If an NV has not enough bits in its mantissa to
308 * represent a UV this summing of small low-order numbers
309 * is a waste of time (because the NV cannot preserve
310 * the low-order bits anyway): we could just remember when
311 * did we overflow and in the end just multiply value_nv by the
312 * right amount of 16-tuples. */
313 value_nv += (NV) XDIGIT_VALUE(*s);
316 if (*s == '_' && len && allow_underscores && s[1]
323 if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT))
324 Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT),
325 "Illegal hexadecimal digit '%c' ignored", *s);
329 if ( ( overflowed && value_nv > 4294967295.0)
331 || (!overflowed && value > 0xffffffff
332 && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE))
335 Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE),
336 "Hexadecimal number > 0xffffffff non-portable");
343 *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
352 converts a string representing an octal number to numeric form.
354 On entry C<start> and C<*len> give the string to scan, C<*flags> gives
355 conversion flags, and C<result> should be C<NULL> or a pointer to an NV.
356 The scan stops at the end of the string, or the first invalid character.
357 Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in C<*flags>, encountering an
358 8 or 9 will also trigger a warning.
359 On return C<*len> is set to the length of the scanned string,
360 and C<*flags> gives output flags.
362 If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
363 and nothing is written to C<*result>. If the value is > C<UV_MAX>, C<grok_oct>
364 returns C<UV_MAX>, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
365 and writes the value to C<*result> (or the value is discarded if C<result>
368 If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in C<*flags> then the octal
369 number may use C<"_"> characters to separate digits.
373 Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE>
374 which suppresses any message for non-portable numbers, but which are valid
379 Perl_grok_oct(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
381 const char *s = start;
385 const UV max_div_8 = UV_MAX / 8;
386 const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
387 bool overflowed = FALSE;
389 PERL_ARGS_ASSERT_GROK_OCT;
391 for (; len-- && *s; s++) {
393 /* Write it in this wonky order with a goto to attempt to get the
394 compiler to make the common case integer-only loop pretty tight.
398 if (value <= max_div_8) {
399 value = (value << 3) | OCTAL_VALUE(*s);
402 /* Bah. We're just overflowed. */
403 /* diag_listed_as: Integer overflow in %s number */
404 Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW),
405 "Integer overflow in octal number");
407 value_nv = (NV) value;
410 /* If an NV has not enough bits in its mantissa to
411 * represent a UV this summing of small low-order numbers
412 * is a waste of time (because the NV cannot preserve
413 * the low-order bits anyway): we could just remember when
414 * did we overflow and in the end just multiply value_nv by the
415 * right amount of 8-tuples. */
416 value_nv += (NV) OCTAL_VALUE(*s);
419 if (*s == '_' && len && allow_underscores && isOCTAL(s[1])) {
424 /* Allow \octal to work the DWIM way (that is, stop scanning
425 * as soon as non-octal characters are seen, complain only if
426 * someone seems to want to use the digits eight and nine. Since we
427 * know it is not octal, then if isDIGIT, must be an 8 or 9). */
429 if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT))
430 Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT),
431 "Illegal octal digit '%c' ignored", *s);
436 if ( ( overflowed && value_nv > 4294967295.0)
438 || (!overflowed && value > 0xffffffff
439 && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE))
442 Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE),
443 "Octal number > 037777777777 non-portable");
450 *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
459 For backwards compatibility. Use C<grok_bin> instead.
463 For backwards compatibility. Use C<grok_hex> instead.
467 For backwards compatibility. Use C<grok_oct> instead.
473 Perl_scan_bin(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
476 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
477 const UV ruv = grok_bin (start, &len, &flags, &rnv);
479 PERL_ARGS_ASSERT_SCAN_BIN;
482 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
486 Perl_scan_oct(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
489 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
490 const UV ruv = grok_oct (start, &len, &flags, &rnv);
492 PERL_ARGS_ASSERT_SCAN_OCT;
495 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
499 Perl_scan_hex(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
502 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
503 const UV ruv = grok_hex (start, &len, &flags, &rnv);
505 PERL_ARGS_ASSERT_SCAN_HEX;
508 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
512 =for apidoc grok_numeric_radix
514 Scan and skip for a numeric decimal separator (radix).
519 Perl_grok_numeric_radix(pTHX_ const char **sp, const char *send)
521 PERL_ARGS_ASSERT_GROK_NUMERIC_RADIX;
523 #ifdef USE_LOCALE_NUMERIC
525 if (IN_LC(LC_NUMERIC)) {
528 bool matches_radix = FALSE;
529 DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
531 STORE_LC_NUMERIC_FORCE_TO_UNDERLYING();
533 radix = SvPV(PL_numeric_radix_sv, len);
534 radix = savepvn(radix, len);
536 RESTORE_LC_NUMERIC();
538 if (*sp + len <= send) {
539 matches_radix = memEQ(*sp, radix, len);
552 /* always try "." if numeric radix didn't match because
553 * we may have data from different locales mixed */
554 if (*sp < send && **sp == '.') {
563 =for apidoc grok_infnan
565 Helper for C<grok_number()>, accepts various ways of spelling "infinity"
566 or "not a number", and returns one of the following flag combinations:
570 IS_NUMBER_INFINITE | IS_NUMBER_NEG
571 IS_NUMBER_NAN | IS_NUMBER_NEG
574 possibly |-ed with C<IS_NUMBER_TRAILING>.
576 If an infinity or a not-a-number is recognized, C<*sp> will point to
577 one byte past the end of the recognized string. If the recognition fails,
578 zero is returned, and C<*sp> will not move.
584 Perl_grok_infnan(pTHX_ const char** sp, const char* send)
588 #if defined(NV_INF) || defined(NV_NAN)
589 bool odh = FALSE; /* one-dot-hash: 1.#INF */
591 PERL_ARGS_ASSERT_GROK_INFNAN;
594 s++; if (s == send) return 0;
596 else if (*s == '-') {
597 flags |= IS_NUMBER_NEG; /* Yes, -NaN happens. Incorrect but happens. */
598 s++; if (s == send) return 0;
602 /* Visual C: 1.#SNAN, -1.#QNAN, 1#INF, 1.#IND (maybe also 1.#NAN)
603 * Let's keep the dot optional. */
604 s++; if (s == send) return 0;
606 s++; if (s == send) return 0;
609 s++; if (s == send) return 0;
615 if (isALPHA_FOLD_EQ(*s, 'I')) {
616 /* INF or IND (1.#IND is "indeterminate", a certain type of NAN) */
618 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return 0;
619 s++; if (s == send) return 0;
620 if (isALPHA_FOLD_EQ(*s, 'F')) {
622 if (s < send && (isALPHA_FOLD_EQ(*s, 'I'))) {
624 flags | IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT | IS_NUMBER_TRAILING;
625 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return fail;
626 s++; if (s == send || isALPHA_FOLD_NE(*s, 'I')) return fail;
627 s++; if (s == send || isALPHA_FOLD_NE(*s, 'T')) return fail;
628 s++; if (s == send || isALPHA_FOLD_NE(*s, 'Y')) return fail;
631 while (*s == '0') { /* 1.#INF00 */
635 while (s < send && isSPACE(*s))
637 if (s < send && *s) {
638 flags |= IS_NUMBER_TRAILING;
640 flags |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT;
642 else if (isALPHA_FOLD_EQ(*s, 'D') && odh) { /* 1.#IND */
644 flags |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
645 while (*s == '0') { /* 1.#IND00 */
649 flags |= IS_NUMBER_TRAILING;
655 /* Maybe NAN of some sort */
657 if (isALPHA_FOLD_EQ(*s, 'S') || isALPHA_FOLD_EQ(*s, 'Q')) {
659 /* XXX do something with the snan/qnan difference */
660 s++; if (s == send) return 0;
663 if (isALPHA_FOLD_EQ(*s, 'N')) {
664 s++; if (s == send || isALPHA_FOLD_NE(*s, 'A')) return 0;
665 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return 0;
668 flags |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
670 /* NaN can be followed by various stuff (NaNQ, NaNS), but
671 * there are also multiple different NaN values, and some
672 * implementations output the "payload" values,
673 * e.g. NaN123, NAN(abc), while some legacy implementations
674 * have weird stuff like NaN%. */
675 if (isALPHA_FOLD_EQ(*s, 'q') ||
676 isALPHA_FOLD_EQ(*s, 's')) {
677 /* "nanq" or "nans" are ok, though generating
678 * these portably is tricky. */
682 /* C99 style "nan(123)" or Perlish equivalent "nan($uv)". */
686 return flags | IS_NUMBER_TRAILING;
689 while (t < send && *t && *t != ')') {
693 return flags | IS_NUMBER_TRAILING;
698 if (s[0] == '0' && s + 2 < t &&
699 isALPHA_FOLD_EQ(s[1], 'x') &&
702 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES;
703 nanval = grok_hex(s, &len, &flags, NULL);
704 if ((flags & PERL_SCAN_GREATER_THAN_UV_MAX)) {
707 nantype = IS_NUMBER_IN_UV;
710 } else if (s[0] == '0' && s + 2 < t &&
711 isALPHA_FOLD_EQ(s[1], 'b') &&
712 (s[2] == '0' || s[2] == '1')) {
714 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES;
715 nanval = grok_bin(s, &len, &flags, NULL);
716 if ((flags & PERL_SCAN_GREATER_THAN_UV_MAX)) {
719 nantype = IS_NUMBER_IN_UV;
725 grok_number_flags(s, t - s, &nanval,
727 PERL_SCAN_ALLOW_UNDERSCORES);
728 /* Unfortunately grok_number_flags() doesn't
729 * tell how far we got and the ')' will always
730 * be "trailing", so we need to double-check
731 * whether we had something dubious. */
732 for (u = s; u < t; u++) {
734 flags |= IS_NUMBER_TRAILING;
741 /* XXX Doesn't do octal: nan("0123").
742 * Probably not a big loss. */
744 if ((nantype & IS_NUMBER_NOT_INT) ||
745 !(nantype && IS_NUMBER_IN_UV)) {
746 /* XXX the nanval is currently unused, that is,
747 * not inserted as the NaN payload of the NV.
748 * But the above code already parses the C99
749 * nan(...) format. See below, and see also
750 * the nan() in POSIX.xs.
752 * Certain configuration combinations where
753 * NVSIZE is greater than UVSIZE mean that
754 * a single UV cannot contain all the possible
755 * NaN payload bits. There would need to be
756 * some more generic syntax than "nan($uv)".
758 * Issues to keep in mind:
760 * (1) In most common cases there would
761 * not be an integral number of bytes that
762 * could be set, only a certain number of bits.
763 * For example for the common case of
764 * NVSIZE == UVSIZE == 8 there is room for 52
765 * bits in the payload, but the most significant
766 * bit is commonly reserved for the
767 * signaling/quiet bit, leaving 51 bits.
768 * Furthermore, the C99 nan() is supposed
769 * to generate quiet NaNs, so it is doubtful
770 * whether it should be able to generate
771 * signaling NaNs. For the x86 80-bit doubles
772 * (if building a long double Perl) there would
773 * be 62 bits (s/q bit being the 63rd).
775 * (2) Endianness of the payload bits. If the
776 * payload is specified as an UV, the low-order
777 * bits of the UV are naturally little-endianed
778 * (rightmost) bits of the payload. The endianness
779 * of UVs and NVs can be different. */
783 flags |= IS_NUMBER_TRAILING;
786 /* Looked like nan(...), but no close paren. */
787 flags |= IS_NUMBER_TRAILING;
790 while (s < send && isSPACE(*s))
792 if (s < send && *s) {
793 /* Note that we here implicitly accept (parse as
794 * "nan", but with warnings) also any other weird
795 * trailing stuff for "nan". In the above we just
796 * check that if we got the C99-style "nan(...)",
797 * the "..." looks sane.
798 * If in future we accept more ways of specifying
799 * the nan payload, the accepting would happen around
801 flags |= IS_NUMBER_TRAILING;
810 while (s < send && isSPACE(*s))
814 PERL_UNUSED_ARG(send);
815 #endif /* #if defined(NV_INF) || defined(NV_NAN) */
821 =for apidoc grok_number_flags
823 Recognise (or not) a number. The type of the number is returned
824 (0 if unrecognised), otherwise it is a bit-ORed combination of
825 C<IS_NUMBER_IN_UV>, C<IS_NUMBER_GREATER_THAN_UV_MAX>, C<IS_NUMBER_NOT_INT>,
826 C<IS_NUMBER_NEG>, C<IS_NUMBER_INFINITY>, C<IS_NUMBER_NAN> (defined in perl.h).
828 If the value of the number can fit in a UV, it is returned in C<*valuep>.
829 C<IS_NUMBER_IN_UV> will be set to indicate that C<*valuep> is valid, C<IS_NUMBER_IN_UV>
830 will never be set unless C<*valuep> is valid, but C<*valuep> may have been assigned
831 to during processing even though C<IS_NUMBER_IN_UV> is not set on return.
832 If C<valuep> is C<NULL>, C<IS_NUMBER_IN_UV> will be set for the same cases as when
833 C<valuep> is non-C<NULL>, but no actual assignment (or SEGV) will occur.
835 C<IS_NUMBER_NOT_INT> will be set with C<IS_NUMBER_IN_UV> if trailing decimals were
836 seen (in which case C<*valuep> gives the true value truncated to an integer), and
837 C<IS_NUMBER_NEG> if the number is negative (in which case C<*valuep> holds the
838 absolute value). C<IS_NUMBER_IN_UV> is not set if e notation was used or the
839 number is larger than a UV.
841 C<flags> allows only C<PERL_SCAN_TRAILING>, which allows for trailing
842 non-numeric text on an otherwise successful I<grok>, setting
843 C<IS_NUMBER_TRAILING> on the result.
845 =for apidoc grok_number
847 Identical to C<grok_number_flags()> with C<flags> set to zero.
852 Perl_grok_number(pTHX_ const char *pv, STRLEN len, UV *valuep)
854 PERL_ARGS_ASSERT_GROK_NUMBER;
856 return grok_number_flags(pv, len, valuep, 0);
859 static const UV uv_max_div_10 = UV_MAX / 10;
860 static const U8 uv_max_mod_10 = UV_MAX % 10;
863 Perl_grok_number_flags(pTHX_ const char *pv, STRLEN len, UV *valuep, U32 flags)
866 const char * const send = pv + len;
870 PERL_ARGS_ASSERT_GROK_NUMBER_FLAGS;
872 while (s < send && isSPACE(*s))
876 } else if (*s == '-') {
878 numtype = IS_NUMBER_NEG;
886 /* The first digit (after optional sign): note that might
887 * also point to "infinity" or "nan", or "1.#INF". */
890 /* next must be digit or the radix separator or beginning of infinity/nan */
892 /* UVs are at least 32 bits, so the first 9 decimal digits cannot
895 /* This construction seems to be more optimiser friendly.
896 (without it gcc does the isDIGIT test and the *s - '0' separately)
897 With it gcc on arm is managing 6 instructions (6 cycles) per digit.
898 In theory the optimiser could deduce how far to unroll the loop
899 before checking for overflow. */
901 int digit = *s - '0';
902 if (digit >= 0 && digit <= 9) {
903 value = value * 10 + digit;
906 if (digit >= 0 && digit <= 9) {
907 value = value * 10 + digit;
910 if (digit >= 0 && digit <= 9) {
911 value = value * 10 + digit;
914 if (digit >= 0 && digit <= 9) {
915 value = value * 10 + digit;
918 if (digit >= 0 && digit <= 9) {
919 value = value * 10 + digit;
922 if (digit >= 0 && digit <= 9) {
923 value = value * 10 + digit;
926 if (digit >= 0 && digit <= 9) {
927 value = value * 10 + digit;
930 if (digit >= 0 && digit <= 9) {
931 value = value * 10 + digit;
933 /* Now got 9 digits, so need to check
934 each time for overflow. */
936 while (digit >= 0 && digit <= 9
937 && (value < uv_max_div_10
938 || (value == uv_max_div_10
939 && digit <= uv_max_mod_10))) {
940 value = value * 10 + digit;
946 if (digit >= 0 && digit <= 9
949 skip the remaining digits, don't
950 worry about setting *valuep. */
953 } while (s < send && isDIGIT(*s));
955 IS_NUMBER_GREATER_THAN_UV_MAX;
975 numtype |= IS_NUMBER_IN_UV;
980 if (GROK_NUMERIC_RADIX(&s, send)) {
981 numtype |= IS_NUMBER_NOT_INT;
982 while (s < send && isDIGIT(*s)) /* optional digits after the radix */
986 else if (GROK_NUMERIC_RADIX(&s, send)) {
987 numtype |= IS_NUMBER_NOT_INT | IS_NUMBER_IN_UV; /* valuep assigned below */
988 /* no digits before the radix means we need digits after it */
989 if (s < send && isDIGIT(*s)) {
992 } while (s < send && isDIGIT(*s));
994 /* integer approximation is valid - it's 0. */
1002 if (s > d && s < send) {
1003 /* we can have an optional exponent part */
1004 if (isALPHA_FOLD_EQ(*s, 'e')) {
1006 if (s < send && (*s == '-' || *s == '+'))
1008 if (s < send && isDIGIT(*s)) {
1011 } while (s < send && isDIGIT(*s));
1013 else if (flags & PERL_SCAN_TRAILING)
1014 return numtype | IS_NUMBER_TRAILING;
1018 /* The only flag we keep is sign. Blow away any "it's UV" */
1019 numtype &= IS_NUMBER_NEG;
1020 numtype |= IS_NUMBER_NOT_INT;
1023 while (s < send && isSPACE(*s))
1027 if (memEQs(pv, len, "0 but true")) {
1030 return IS_NUMBER_IN_UV;
1032 /* We could be e.g. at "Inf" or "NaN", or at the "#" of "1.#INF". */
1033 if ((s + 2 < send) && strchr("inqs#", toFOLD(*s))) {
1034 /* Really detect inf/nan. Start at d, not s, since the above
1035 * code might have already consumed the "1." or "1". */
1036 const int infnan = Perl_grok_infnan(aTHX_ &d, send);
1037 if ((infnan & IS_NUMBER_INFINITY)) {
1038 return (numtype | infnan); /* Keep sign for infinity. */
1040 else if ((infnan & IS_NUMBER_NAN)) {
1041 return (numtype | infnan) & ~IS_NUMBER_NEG; /* Clear sign for nan. */
1044 else if (flags & PERL_SCAN_TRAILING) {
1045 return numtype | IS_NUMBER_TRAILING;
1054 grok_atoUV parses a C-style zero-byte terminated string, looking for
1055 a decimal unsigned integer.
1057 Returns the unsigned integer, if a valid value can be parsed
1058 from the beginning of the string.
1060 Accepts only the decimal digits '0'..'9'.
1062 As opposed to atoi or strtol, grok_atoUV does NOT allow optional
1063 leading whitespace, or negative inputs. If such features are
1064 required, the calling code needs to explicitly implement those.
1066 Returns true if a valid value could be parsed. In that case, valptr
1067 is set to the parsed value, and endptr (if provided) is set to point
1068 to the character after the last digit.
1070 Returns false otherwise. This can happen if a) there is a leading zero
1071 followed by another digit; b) the digits would overflow a UV; or c)
1072 there are trailing non-digits AND endptr is not provided.
1074 Background: atoi has severe problems with illegal inputs, it cannot be
1075 used for incremental parsing, and therefore should be avoided
1076 atoi and strtol are also affected by locale settings, which can also be
1077 seen as a bug (global state controlled by user environment).
1082 Perl_grok_atoUV(const char *pv, UV *valptr, const char** endptr)
1086 const char* end2; /* Used in case endptr is NULL. */
1087 UV val = 0; /* The parsed value. */
1089 PERL_ARGS_ASSERT_GROK_ATOUV;
1091 eptr = endptr ? endptr : &end2;
1093 /* Single-digit inputs are quite common. */
1096 /* Fail on extra leading zeros. */
1099 while (isDIGIT(*s)) {
1100 /* This could be unrolled like in grok_number(), but
1101 * the expected uses of this are not speed-needy, and
1102 * unlikely to need full 64-bitness. */
1103 const U8 digit = *s++ - '0';
1104 if (val < uv_max_div_10 ||
1105 (val == uv_max_div_10 && digit <= uv_max_mod_10)) {
1106 val = val * 10 + digit;
1115 if (endptr == NULL && *s)
1116 return FALSE; /* If endptr is NULL, no trailing non-digits allowed. */
1122 #ifndef USE_QUADMATH
1124 S_mulexp10(NV value, I32 exponent)
1136 /* On OpenVMS VAX we by default use the D_FLOAT double format,
1137 * and that format does not have *easy* capabilities [1] for
1138 * overflowing doubles 'silently' as IEEE fp does. We also need
1139 * to support G_FLOAT on both VAX and Alpha, and though the exponent
1140 * range is much larger than D_FLOAT it still doesn't do silent
1141 * overflow. Therefore we need to detect early whether we would
1142 * overflow (this is the behaviour of the native string-to-float
1143 * conversion routines, and therefore of native applications, too).
1145 * [1] Trying to establish a condition handler to trap floating point
1146 * exceptions is not a good idea. */
1148 /* In UNICOS and in certain Cray models (such as T90) there is no
1149 * IEEE fp, and no way at all from C to catch fp overflows gracefully.
1150 * There is something you can do if you are willing to use some
1151 * inline assembler: the instruction is called DFI-- but that will
1152 * disable *all* floating point interrupts, a little bit too large
1153 * a hammer. Therefore we need to catch potential overflows before
1156 #if ((defined(VMS) && !defined(_IEEE_FP)) || defined(_UNICOS) || defined(DOUBLE_IS_VAX_FLOAT)) && defined(NV_MAX_10_EXP)
1158 const NV exp_v = log10(value);
1159 if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP)
1162 if (-(exponent + exp_v) >= NV_MAX_10_EXP)
1164 while (-exponent >= NV_MAX_10_EXP) {
1165 /* combination does not overflow, but 10^(-exponent) does */
1175 exponent = -exponent;
1176 #ifdef NV_MAX_10_EXP
1177 /* for something like 1234 x 10^-309, the action of calculating
1178 * the intermediate value 10^309 then returning 1234 / (10^309)
1179 * will fail, since 10^309 becomes infinity. In this case try to
1180 * refactor it as 123 / (10^308) etc.
1182 while (value && exponent > NV_MAX_10_EXP) {
1190 #if defined(__osf__)
1191 /* Even with cc -ieee + ieee_set_fp_control(IEEE_TRAP_ENABLE_INV)
1192 * Tru64 fp behavior on inf/nan is somewhat broken. Another way
1193 * to do this would be ieee_set_fp_control(IEEE_TRAP_ENABLE_OVF)
1194 * but that breaks another set of infnan.t tests. */
1195 # define FP_OVERFLOWS_TO_ZERO
1197 for (bit = 1; exponent; bit <<= 1) {
1198 if (exponent & bit) {
1201 #ifdef FP_OVERFLOWS_TO_ZERO
1204 return value < 0 ? -NV_INF : NV_INF;
1206 return value < 0 ? -FLT_MAX : FLT_MAX;
1209 /* Floating point exceptions are supposed to be turned off,
1210 * but if we're obviously done, don't risk another iteration.
1212 if (exponent == 0) break;
1216 return negative ? value / result : value * result;
1218 #endif /* #ifndef USE_QUADMATH */
1221 Perl_my_atof(pTHX_ const char* s)
1223 /* 's' must be NUL terminated */
1227 PERL_ARGS_ASSERT_MY_ATOF;
1231 Perl_my_atof2(aTHX_ s, &x);
1233 #elif ! defined(USE_LOCALE_NUMERIC)
1240 DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
1241 STORE_LC_NUMERIC_SET_TO_NEEDED();
1242 if (PL_numeric_radix_sv && IN_LC(LC_NUMERIC)) {
1243 /* Look through the string for the first thing that looks like a
1244 * decimal point: either the value in the current locale or the
1245 * standard fallback of '.'. The one which appears earliest in the
1246 * input string is the one that we should have atof look for. Note
1247 * that we have to determine this beforehand because on some
1248 * systems, Perl_atof2 is just a wrapper around the system's atof.
1250 const char * const standard_pos = strchr(s, '.');
1251 const char * const local_pos
1252 = strstr(s, SvPV_nolen(PL_numeric_radix_sv));
1253 const bool use_standard_radix
1254 = standard_pos && (!local_pos || standard_pos < local_pos);
1256 if (use_standard_radix) {
1257 SET_NUMERIC_STANDARD();
1258 LOCK_LC_NUMERIC_STANDARD();
1263 if (use_standard_radix) {
1264 UNLOCK_LC_NUMERIC_STANDARD();
1265 SET_NUMERIC_UNDERLYING();
1270 RESTORE_LC_NUMERIC();
1278 #if defined(NV_INF) || defined(NV_NAN)
1281 # pragma warning(push)
1282 # pragma warning(disable:4756;disable:4056)
1285 S_my_atof_infnan(pTHX_ const char* s, bool negative, const char* send, NV* value)
1287 const char *p0 = negative ? s - 1 : s;
1289 const int infnan = grok_infnan(&p, send);
1290 if (infnan && p != p0) {
1291 /* If we can generate inf/nan directly, let's do so. */
1293 if ((infnan & IS_NUMBER_INFINITY)) {
1294 *value = (infnan & IS_NUMBER_NEG) ? -NV_INF: NV_INF;
1299 if ((infnan & IS_NUMBER_NAN)) {
1305 /* If still here, we didn't have either NV_INF or NV_NAN,
1306 * and can try falling back to native strtod/strtold.
1308 * The native interface might not recognize all the possible
1309 * inf/nan strings Perl recognizes. What we can try
1310 * is to try faking the input. We will try inf/-inf/nan
1311 * as the most promising/portable input. */
1313 const char* fake = NULL;
1317 if ((infnan & IS_NUMBER_INFINITY)) {
1318 fake = ((infnan & IS_NUMBER_NEG)) ? "-inf" : "inf";
1322 if ((infnan & IS_NUMBER_NAN)) {
1327 nv = Perl_strtod(fake, &endp);
1330 if ((infnan & IS_NUMBER_INFINITY)) {
1335 /* last resort, may generate SIGFPE */
1336 *value = Perl_exp((NV)1e9);
1337 if ((infnan & IS_NUMBER_NEG))
1340 return (char*)p; /* p, not endp */
1344 if ((infnan & IS_NUMBER_NAN)) {
1349 /* last resort, may generate SIGFPE */
1350 *value = Perl_log((NV)-1.0);
1352 return (char*)p; /* p, not endp */
1357 #endif /* #ifdef Perl_strtod */
1362 # pragma warning(pop)
1365 #endif /* if defined(NV_INF) || defined(NV_NAN) */
1368 Perl_my_atof2(pTHX_ const char* orig, NV* value)
1370 const char* s = orig;
1371 NV result[3] = {0.0, 0.0, 0.0};
1372 #if defined(USE_PERL_ATOF) || defined(USE_QUADMATH)
1373 const char* send = s + strlen(orig); /* one past the last */
1376 #if defined(USE_PERL_ATOF) && !defined(USE_QUADMATH)
1377 UV accumulator[2] = {0,0}; /* before/after dp */
1378 bool seen_digit = 0;
1379 I32 exp_adjust[2] = {0,0};
1380 I32 exp_acc[2] = {-1, -1};
1381 /* the current exponent adjust for the accumulators */
1386 I32 sig_digits = 0; /* noof significant digits seen so far */
1389 #if defined(USE_PERL_ATOF) || defined(USE_QUADMATH)
1390 PERL_ARGS_ASSERT_MY_ATOF2;
1392 /* leading whitespace */
1409 if ((endp = S_my_atof_infnan(aTHX_ s, negative, send, value)))
1411 result[2] = strtoflt128(s, &endp);
1413 *value = negative ? -result[2] : result[2];
1418 #elif defined(USE_PERL_ATOF)
1420 /* There is no point in processing more significant digits
1421 * than the NV can hold. Note that NV_DIG is a lower-bound value,
1422 * while we need an upper-bound value. We add 2 to account for this;
1423 * since it will have been conservative on both the first and last digit.
1424 * For example a 32-bit mantissa with an exponent of 4 would have
1425 * exact values in the set
1433 * where for the purposes of calculating NV_DIG we would have to discount
1434 * both the first and last digit, since neither can hold all values from
1435 * 0..9; but for calculating the value we must examine those two digits.
1437 #ifdef MAX_SIG_DIG_PLUS
1438 /* It is not necessarily the case that adding 2 to NV_DIG gets all the
1439 possible digits in a NV, especially if NVs are not IEEE compliant
1440 (e.g., long doubles on IRIX) - Allen <allens@cpan.org> */
1441 # define MAX_SIG_DIGITS (NV_DIG+MAX_SIG_DIG_PLUS)
1443 # define MAX_SIG_DIGITS (NV_DIG+2)
1446 /* the max number we can accumulate in a UV, and still safely do 10*N+9 */
1447 #define MAX_ACCUMULATE ( (UV) ((UV_MAX - 9)/10))
1449 #if defined(NV_INF) || defined(NV_NAN)
1452 if ((endp = S_my_atof_infnan(aTHX_ s, negative, send, value)))
1457 /* we accumulate digits into an integer; when this becomes too
1458 * large, we add the total to NV and start again */
1468 /* don't start counting until we see the first significant
1469 * digit, eg the 5 in 0.00005... */
1470 if (!sig_digits && digit == 0)
1473 if (++sig_digits > MAX_SIG_DIGITS) {
1474 /* limits of precision reached */
1476 ++accumulator[seen_dp];
1477 } else if (digit == 5) {
1478 if (old_digit % 2) { /* round to even - Allen */
1479 ++accumulator[seen_dp];
1487 /* skip remaining digits */
1488 while (isDIGIT(*s)) {
1494 /* warn of loss of precision? */
1497 if (accumulator[seen_dp] > MAX_ACCUMULATE) {
1498 /* add accumulator to result and start again */
1499 result[seen_dp] = S_mulexp10(result[seen_dp],
1501 + (NV)accumulator[seen_dp];
1502 accumulator[seen_dp] = 0;
1503 exp_acc[seen_dp] = 0;
1505 accumulator[seen_dp] = accumulator[seen_dp] * 10 + digit;
1509 else if (!seen_dp && GROK_NUMERIC_RADIX(&s, send)) {
1511 if (sig_digits > MAX_SIG_DIGITS) {
1512 while (isDIGIT(*s)) {
1523 result[0] = S_mulexp10(result[0], exp_acc[0]) + (NV)accumulator[0];
1525 result[1] = S_mulexp10(result[1], exp_acc[1]) + (NV)accumulator[1];
1528 if (seen_digit && (isALPHA_FOLD_EQ(*s, 'e'))) {
1529 bool expnegative = 0;
1540 exponent = exponent * 10 + (*s++ - '0');
1542 exponent = -exponent;
1547 /* now apply the exponent */
1550 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0])
1551 + S_mulexp10(result[1],exponent-exp_adjust[1]);
1553 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]);
1556 /* now apply the sign */
1558 result[2] = -result[2];
1559 #endif /* USE_PERL_ATOF */
1565 =for apidoc isinfnan
1567 C<Perl_isinfnan()> is utility function that returns true if the NV
1568 argument is either an infinity or a C<NaN>, false otherwise. To test
1569 in more detail, use C<Perl_isinf()> and C<Perl_isnan()>.
1571 This is also the logical inverse of Perl_isfinite().
1576 Perl_isinfnan(NV nv)
1578 PERL_UNUSED_ARG(nv);
1593 Checks whether the argument would be either an infinity or C<NaN> when used
1594 as a number, but is careful not to trigger non-numeric or uninitialized
1595 warnings. it assumes the caller has done C<SvGETMAGIC(sv)> already.
1601 Perl_isinfnansv(pTHX_ SV *sv)
1603 PERL_ARGS_ASSERT_ISINFNANSV;
1607 return Perl_isinfnan(SvNVX(sv));
1612 const char *s = SvPV_nomg_const(sv, len);
1613 return cBOOL(grok_infnan(&s, s+len));
1618 /* C99 has truncl, pre-C99 Solaris had aintl. We can use either with
1619 * copysignl to emulate modfl, which is in some platforms missing or
1621 # if defined(HAS_TRUNCL) && defined(HAS_COPYSIGNL)
1623 Perl_my_modfl(long double x, long double *ip)
1626 return (x == *ip ? copysignl(0.0L, x) : x - *ip);
1628 # elif defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
1630 Perl_my_modfl(long double x, long double *ip)
1633 return (x == *ip ? copysignl(0.0L, x) : x - *ip);
1638 /* Similarly, with ilogbl and scalbnl we can emulate frexpl. */
1639 #if ! defined(HAS_FREXPL) && defined(HAS_ILOGBL) && defined(HAS_SCALBNL)
1641 Perl_my_frexpl(long double x, int *e) {
1642 *e = x == 0.0L ? 0 : ilogbl(x) + 1;
1643 return (scalbnl(x, -*e));
1648 =for apidoc Perl_signbit
1650 Return a non-zero integer if the sign bit on an NV is set, and 0 if
1653 If F<Configure> detects this system has a C<signbit()> that will work with
1654 our NVs, then we just use it via the C<#define> in F<perl.h>. Otherwise,
1655 fall back on this implementation. The main use of this function
1656 is catching C<-0.0>.
1658 C<Configure> notes: This function is called C<'Perl_signbit'> instead of a
1659 plain C<'signbit'> because it is easy to imagine a system having a C<signbit()>
1660 function or macro that doesn't happen to work with our particular choice
1661 of NVs. We shouldn't just re-C<#define> C<signbit> as C<Perl_signbit> and expect
1662 the standard system headers to be happy. Also, this is a no-context
1663 function (no C<pTHX_>) because C<Perl_signbit()> is usually re-C<#defined> in
1664 F<perl.h> as a simple macro call to the system's C<signbit()>.
1665 Users should just always call C<Perl_signbit()>.
1669 #if !defined(HAS_SIGNBIT)
1671 Perl_signbit(NV x) {
1672 # ifdef Perl_fp_class_nzero
1673 return Perl_fp_class_nzero(x);
1674 /* Try finding the high byte, and assume it's highest bit
1675 * is the sign. This assumption is probably wrong somewhere. */
1676 # elif defined(USE_LONG_DOUBLE) && LONG_DOUBLEKIND == LONG_DOUBLE_IS_X86_80_BIT_LITTLE_ENDIAN
1677 return (((unsigned char *)&x)[9] & 0x80);
1678 # elif defined(NV_LITTLE_ENDIAN)
1679 /* Note that NVSIZE is sizeof(NV), which would make the below be
1680 * wrong if the end bytes are unused, which happens with the x86
1681 * 80-bit long doubles, which is why take care of that above. */
1682 return (((unsigned char *)&x)[NVSIZE - 1] & 0x80);
1683 # elif defined(NV_BIG_ENDIAN)
1684 return (((unsigned char *)&x)[0] & 0x80);
1686 /* This last resort fallback is wrong for the negative zero. */
1687 return (x < 0.0) ? 1 : 0;
1693 * ex: set ts=8 sts=4 sw=4 et: