1 /* numeric.c
2 *
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
5 *
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.
8 *
9 */
10
11 /*
12 * "That only makes eleven (plus one mislaid) and not fourteen,
13 * unless wizards count differently to other people." --Beorn
14 *
15 * [p.115 of _The Hobbit_: "Queer Lodgings"]
16 */
17
18 /*
19
20 This file contains all the stuff needed by perl for manipulating numeric
21 values, including such things as replacements for the OS's atof() function
22
23 */
24
25 #include "EXTERN.h"
26 #define PERL_IN_NUMERIC_C
27 #include "perl.h"
28
29 #ifdef Perl_strtod
30
31 PERL_STATIC_INLINE NV
S_strtod(pTHX_ const char * const s,char ** e)32 S_strtod(pTHX_ const char * const s, char ** e)
33 {
34 DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
35 NV result;
36
37 STORE_LC_NUMERIC_SET_TO_NEEDED();
38
39 # ifdef USE_QUADMATH
40
41 result = strtoflt128(s, e);
42
43 # elif defined(HAS_STRTOLD) && defined(HAS_LONG_DOUBLE) \
44 && defined(USE_LONG_DOUBLE)
45 # if defined(__MINGW64_VERSION_MAJOR)
46 /***********************************************
47 We are unable to use strtold because of
48 https://sourceforge.net/p/mingw-w64/bugs/711/
49 &
50 https://sourceforge.net/p/mingw-w64/bugs/725/
51
52 but __mingw_strtold is fine.
53 ***********************************************/
54
55 result = __mingw_strtold(s, e);
56
57 # else
58
59 result = strtold(s, e);
60
61 # endif
62 # elif defined(HAS_STRTOD)
63
64 result = strtod(s, e);
65
66 # else
67 # error No strtod() equivalent found
68 # endif
69
70 RESTORE_LC_NUMERIC();
71
72 return result;
73 }
74
75 #endif /* #ifdef Perl_strtod */
76
77 /*
78
79 =for apidoc my_strtod
80
81 This function is equivalent to the libc strtod() function, and is available
82 even on platforms that lack plain strtod(). Its return value is the best
83 available precision depending on platform capabilities and F<Configure>
84 options.
85
86 It properly handles the locale radix character, meaning it expects a dot except
87 when called from within the scope of S<C<use locale>>, in which case the radix
88 character should be that specified by the current locale.
89
90 The synonym Strtod() may be used instead.
91
92 =cut
93
94 */
95
96 NV
Perl_my_strtod(const char * const s,char ** e)97 Perl_my_strtod(const char * const s, char **e)
98 {
99 dTHX;
100
101 PERL_ARGS_ASSERT_MY_STRTOD;
102
103 #ifdef Perl_strtod
104
105 return S_strtod(aTHX_ s, e);
106
107 #else
108
109 {
110 NV result;
111 char ** end_ptr = NULL;
112
113 *end_ptr = my_atof2(s, &result);
114 if (e) {
115 *e = *end_ptr;
116 }
117
118 if (! *end_ptr) {
119 result = 0.0;
120 }
121
122 return result;
123 }
124
125 #endif
126
127 }
128
129
130 U32
Perl_cast_ulong(NV f)131 Perl_cast_ulong(NV f)
132 {
133 if (f < 0.0)
134 return f < I32_MIN ? (U32) I32_MIN : (U32)(I32) f;
135 if (f < U32_MAX_P1) {
136 #if CASTFLAGS & 2
137 if (f < U32_MAX_P1_HALF)
138 return (U32) f;
139 f -= U32_MAX_P1_HALF;
140 return ((U32) f) | (1 + (U32_MAX >> 1));
141 #else
142 return (U32) f;
143 #endif
144 }
145 return f > 0 ? U32_MAX : 0 /* NaN */;
146 }
147
148 I32
Perl_cast_i32(NV f)149 Perl_cast_i32(NV f)
150 {
151 if (f < I32_MAX_P1)
152 return f < I32_MIN ? I32_MIN : (I32) f;
153 if (f < U32_MAX_P1) {
154 #if CASTFLAGS & 2
155 if (f < U32_MAX_P1_HALF)
156 return (I32)(U32) f;
157 f -= U32_MAX_P1_HALF;
158 return (I32)(((U32) f) | (1 + (U32_MAX >> 1)));
159 #else
160 return (I32)(U32) f;
161 #endif
162 }
163 return f > 0 ? (I32)U32_MAX : 0 /* NaN */;
164 }
165
166 IV
Perl_cast_iv(NV f)167 Perl_cast_iv(NV f)
168 {
169 if (f < IV_MAX_P1)
170 return f < IV_MIN ? IV_MIN : (IV) f;
171 if (f < UV_MAX_P1) {
172 #if CASTFLAGS & 2
173 /* For future flexibility allowing for sizeof(UV) >= sizeof(IV) */
174 if (f < UV_MAX_P1_HALF)
175 return (IV)(UV) f;
176 f -= UV_MAX_P1_HALF;
177 return (IV)(((UV) f) | (1 + (UV_MAX >> 1)));
178 #else
179 return (IV)(UV) f;
180 #endif
181 }
182 return f > 0 ? (IV)UV_MAX : 0 /* NaN */;
183 }
184
185 UV
Perl_cast_uv(NV f)186 Perl_cast_uv(NV f)
187 {
188 if (f < 0.0)
189 return f < IV_MIN ? (UV) IV_MIN : (UV)(IV) f;
190 if (f < UV_MAX_P1) {
191 #if CASTFLAGS & 2
192 if (f < UV_MAX_P1_HALF)
193 return (UV) f;
194 f -= UV_MAX_P1_HALF;
195 return ((UV) f) | (1 + (UV_MAX >> 1));
196 #else
197 return (UV) f;
198 #endif
199 }
200 return f > 0 ? UV_MAX : 0 /* NaN */;
201 }
202
203 /*
204 =for apidoc grok_bin
205
206 converts a string representing a binary number to numeric form.
207
208 On entry C<start> and C<*len_p> give the string to scan, C<*flags> gives
209 conversion flags, and C<result> should be C<NULL> or a pointer to an NV. The
210 scan stops at the end of the string, or at just before the first invalid
211 character. Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in C<*flags>,
212 encountering an invalid character (except NUL) will also trigger a warning. On
213 return C<*len_p> is set to the length of the scanned string, and C<*flags>
214 gives output flags.
215
216 If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
217 and nothing is written to C<*result>. If the value is > C<UV_MAX>, C<grok_bin>
218 returns C<UV_MAX>, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
219 and writes an approximation of the correct value into C<*result> (which is an
220 NV; or the approximation is discarded if C<result> is NULL).
221
222 The binary number may optionally be prefixed with C<"0b"> or C<"b"> unless
223 C<PERL_SCAN_DISALLOW_PREFIX> is set in C<*flags> on entry.
224
225 If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in C<*flags> then any or all pairs of
226 digits may be separated from each other by a single underscore; also a single
227 leading underscore is accepted.
228
229 =for apidoc Amnh||PERL_SCAN_ALLOW_UNDERSCORES
230 =for apidoc Amnh||PERL_SCAN_DISALLOW_PREFIX
231 =for apidoc Amnh||PERL_SCAN_GREATER_THAN_UV_MAX
232 =for apidoc Amnh||PERL_SCAN_SILENT_ILLDIGIT
233
234 =cut
235
236 Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE
237 which suppresses any message for non-portable numbers that are still valid
238 on this platform.
239 */
240
241 UV
Perl_grok_bin(pTHX_ const char * start,STRLEN * len_p,I32 * flags,NV * result)242 Perl_grok_bin(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
243 {
244 PERL_ARGS_ASSERT_GROK_BIN;
245
246 return grok_bin(start, len_p, flags, result);
247 }
248
249 /*
250 =for apidoc grok_hex
251
252 converts a string representing a hex number to numeric form.
253
254 On entry C<start> and C<*len_p> give the string to scan, C<*flags> gives
255 conversion flags, and C<result> should be C<NULL> or a pointer to an NV. The
256 scan stops at the end of the string, or at just before the first invalid
257 character. Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in C<*flags>,
258 encountering an invalid character (except NUL) will also trigger a warning. On
259 return C<*len_p> is set to the length of the scanned string, and C<*flags>
260 gives output flags.
261
262 If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
263 and nothing is written to C<*result>. If the value is > C<UV_MAX>, C<grok_hex>
264 returns C<UV_MAX>, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
265 and writes an approximation of the correct value into C<*result> (which is an
266 NV; or the approximation is discarded if C<result> is NULL).
267
268 The hex number may optionally be prefixed with C<"0x"> or C<"x"> unless
269 C<PERL_SCAN_DISALLOW_PREFIX> is set in C<*flags> on entry.
270
271 If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in C<*flags> then any or all pairs of
272 digits may be separated from each other by a single underscore; also a single
273 leading underscore is accepted.
274
275 =cut
276
277 Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE>
278 which suppresses any message for non-portable numbers, but which are valid
279 on this platform. But, C<*flags> will have the corresponding flag bit set.
280 */
281
282 UV
Perl_grok_hex(pTHX_ const char * start,STRLEN * len_p,I32 * flags,NV * result)283 Perl_grok_hex(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
284 {
285 PERL_ARGS_ASSERT_GROK_HEX;
286
287 return grok_hex(start, len_p, flags, result);
288 }
289
290 /*
291 =for apidoc grok_oct
292
293 converts a string representing an octal number to numeric form.
294
295 On entry C<start> and C<*len_p> give the string to scan, C<*flags> gives
296 conversion flags, and C<result> should be C<NULL> or a pointer to an NV. The
297 scan stops at the end of the string, or at just before the first invalid
298 character. Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in C<*flags>,
299 encountering an invalid character (except NUL) will also trigger a warning. On
300 return C<*len_p> is set to the length of the scanned string, and C<*flags>
301 gives output flags.
302
303 If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
304 and nothing is written to C<*result>. If the value is > C<UV_MAX>, C<grok_oct>
305 returns C<UV_MAX>, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
306 and writes an approximation of the correct value into C<*result> (which is an
307 NV; or the approximation is discarded if C<result> is NULL).
308
309 If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in C<*flags> then any or all pairs of
310 digits may be separated from each other by a single underscore; also a single
311 leading underscore is accepted.
312
313 The C<PERL_SCAN_DISALLOW_PREFIX> flag is always treated as being set for
314 this function.
315
316 =cut
317
318 Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE>
319 which suppresses any message for non-portable numbers, but which are valid
320 on this platform.
321 */
322
323 UV
Perl_grok_oct(pTHX_ const char * start,STRLEN * len_p,I32 * flags,NV * result)324 Perl_grok_oct(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
325 {
326 PERL_ARGS_ASSERT_GROK_OCT;
327
328 return grok_oct(start, len_p, flags, result);
329 }
330
331 STATIC void
S_output_non_portable(pTHX_ const U8 base)332 S_output_non_portable(pTHX_ const U8 base)
333 {
334 /* Display the proper message for a number in the given input base not
335 * fitting in 32 bits */
336 const char * which = (base == 2)
337 ? "Binary number > 0b11111111111111111111111111111111"
338 : (base == 8)
339 ? "Octal number > 037777777777"
340 : "Hexadecimal number > 0xffffffff";
341
342 PERL_ARGS_ASSERT_OUTPUT_NON_PORTABLE;
343
344 /* Also there are listings for the other two. That's because, since they
345 * are the first word, it would be hard for a user to find them there
346 * starting with a %s */
347 /* diag_listed_as: Hexadecimal number > 0xffffffff non-portable */
348 Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE), "%s non-portable", which);
349 }
350
351 UV
Perl_grok_bin_oct_hex(pTHX_ const char * start,STRLEN * len_p,I32 * flags,NV * result,const unsigned shift,const U8 class_bit,const char prefix)352 Perl_grok_bin_oct_hex(pTHX_ const char *start,
353 STRLEN *len_p,
354 I32 *flags,
355 NV *result,
356 const unsigned shift, /* 1 for binary; 3 for octal;
357 4 for hex */
358 const U8 class_bit,
359 const char prefix
360 )
361
362 {
363 const char *s0 = start;
364 const char *s;
365 STRLEN len = *len_p;
366 STRLEN bytes_so_far; /* How many real digits have been processed */
367 UV value = 0;
368 NV value_nv = 0;
369 const PERL_UINT_FAST8_T base = 1 << shift; /* 2, 8, or 16 */
370 const UV max_div= UV_MAX / base; /* Value above which, the next digit
371 processed would overflow */
372 const I32 input_flags = *flags;
373 const bool allow_underscores =
374 cBOOL(input_flags & PERL_SCAN_ALLOW_UNDERSCORES);
375 bool overflowed = FALSE;
376
377 /* In overflows, this keeps track of how much to multiply the overflowed NV
378 * by as we continue to parse the remaining digits */
379 NV factor = 0;
380
381 /* This function unifies the core of grok_bin, grok_oct, and grok_hex. It
382 * is optimized for hex conversion. For example, it uses XDIGIT_VALUE to
383 * find the numeric value of a digit. That requires more instructions than
384 * OCTAL_VALUE would, but gives the same result for the narrowed range of
385 * octal digits; same for binary. If it were ever critical to squeeze more
386 * performance from this, the function could become grok_hex, and a regen
387 * perl script could scan it and write out two edited copies for the other
388 * two functions. That would improve the performance of all three
389 * somewhat. Besides eliminating XDIGIT_VALUE for the other two, extra
390 * parameters are now passed to this to avoid conditionals. Those could
391 * become declared consts, like:
392 * const U8 base = 16;
393 * const U8 base = 8;
394 * ...
395 */
396
397 PERL_ARGS_ASSERT_GROK_BIN_OCT_HEX;
398
399 ASSUME(inRANGE(shift, 1, 4) && shift != 2);
400
401 /* Clear output flags; unlikely to find a problem that sets them */
402 *flags = 0;
403
404 if (!(input_flags & PERL_SCAN_DISALLOW_PREFIX)) {
405
406 /* strip off leading b or 0b; x or 0x.
407 for compatibility silently suffer "b" and "0b" as valid binary; "x"
408 and "0x" as valid hex numbers. */
409 if (len >= 1) {
410 if (isALPHA_FOLD_EQ(s0[0], prefix)) {
411 s0++;
412 len--;
413 }
414 else if (len >= 2 && s0[0] == '0' && (isALPHA_FOLD_EQ(s0[1], prefix))) {
415 s0+=2;
416 len-=2;
417 }
418 }
419 }
420
421 s = s0; /* s0 potentially advanced from 'start' */
422
423 /* Unroll the loop so that the first 8 digits are branchless except for the
424 * switch. A ninth hex one overflows a 32 bit word. */
425 switch (len) {
426 case 0:
427 return 0;
428 default:
429 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
430 value = (value << shift) | XDIGIT_VALUE(*s);
431 s++;
432 /* FALLTHROUGH */
433 case 7:
434 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
435 value = (value << shift) | XDIGIT_VALUE(*s);
436 s++;
437 /* FALLTHROUGH */
438 case 6:
439 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
440 value = (value << shift) | XDIGIT_VALUE(*s);
441 s++;
442 /* FALLTHROUGH */
443 case 5:
444 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
445 value = (value << shift) | XDIGIT_VALUE(*s);
446 s++;
447 /* FALLTHROUGH */
448 case 4:
449 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
450 value = (value << shift) | XDIGIT_VALUE(*s);
451 s++;
452 /* FALLTHROUGH */
453 case 3:
454 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
455 value = (value << shift) | XDIGIT_VALUE(*s);
456 s++;
457 /* FALLTHROUGH */
458 case 2:
459 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
460 value = (value << shift) | XDIGIT_VALUE(*s);
461 s++;
462 /* FALLTHROUGH */
463 case 1:
464 if (UNLIKELY(! _generic_isCC(*s, class_bit))) break;
465 value = (value << shift) | XDIGIT_VALUE(*s);
466
467 if (LIKELY(len <= 8)) {
468 return value;
469 }
470
471 s++;
472 break;
473 }
474
475 bytes_so_far = s - s0;
476 factor = shift << bytes_so_far;
477 len -= bytes_so_far;
478
479 for (; len--; s++) {
480 if (_generic_isCC(*s, class_bit)) {
481 /* Write it in this wonky order with a goto to attempt to get the
482 compiler to make the common case integer-only loop pretty tight.
483 With gcc seems to be much straighter code than old scan_hex.
484 (khw suspects that adding a LIKELY() just above would do the
485 same thing) */
486 redo:
487 if (LIKELY(value <= max_div)) {
488 value = (value << shift) | XDIGIT_VALUE(*s);
489 /* Note XDIGIT_VALUE() is branchless, works on binary
490 * and octal as well, so can be used here, without
491 * slowing those down */
492 factor *= 1 << shift;
493 continue;
494 }
495
496 /* Bah. We are about to overflow. Instead, add the unoverflowed
497 * value to an NV that contains an approximation to the correct
498 * value. Each time through the loop we have increased 'factor' so
499 * that it gives how much the current approximation needs to
500 * effectively be shifted to make room for this new value */
501 value_nv *= factor;
502 value_nv += (NV) value;
503
504 /* Then we keep accumulating digits, until all are parsed. We
505 * start over using the current input value. This will be added to
506 * 'value_nv' eventually, either when all digits are gone, or we
507 * have overflowed this fresh start. */
508 value = XDIGIT_VALUE(*s);
509 factor = 1 << shift;
510
511 if (! overflowed) {
512 overflowed = TRUE;
513 if ( ! (input_flags & PERL_SCAN_SILENT_OVERFLOW)
514 && ckWARN_d(WARN_OVERFLOW))
515 {
516 Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
517 "Integer overflow in %s number",
518 (base == 16) ? "hexadecimal"
519 : (base == 2)
520 ? "binary"
521 : "octal");
522 }
523 }
524 continue;
525 }
526
527 if ( *s == '_'
528 && len
529 && allow_underscores
530 && _generic_isCC(s[1], class_bit)
531
532 /* Don't allow a leading underscore if the only-medial bit is
533 * set */
534 && ( LIKELY(s > s0)
535 || UNLIKELY((input_flags & PERL_SCAN_ALLOW_MEDIAL_UNDERSCORES)
536 != PERL_SCAN_ALLOW_MEDIAL_UNDERSCORES)))
537 {
538 --len;
539 ++s;
540 goto redo;
541 }
542
543 if (*s) {
544 if ( ! (input_flags & PERL_SCAN_SILENT_ILLDIGIT)
545 && ckWARN(WARN_DIGIT))
546 {
547 if (base != 8) {
548 Perl_warner(aTHX_ packWARN(WARN_DIGIT),
549 "Illegal %s digit '%c' ignored",
550 ((base == 2)
551 ? "binary"
552 : "hexadecimal"),
553 *s);
554 }
555 else if (isDIGIT(*s)) { /* octal base */
556
557 /* Allow \octal to work the DWIM way (that is, stop
558 * scanning as soon as non-octal characters are seen,
559 * complain only if someone seems to want to use the digits
560 * eight and nine. Since we know it is not octal, then if
561 * isDIGIT, must be an 8 or 9). */
562 Perl_warner(aTHX_ packWARN(WARN_DIGIT),
563 "Illegal octal digit '%c' ignored", *s);
564 }
565 }
566
567 if (input_flags & PERL_SCAN_NOTIFY_ILLDIGIT) {
568 *flags |= PERL_SCAN_NOTIFY_ILLDIGIT;
569 }
570 }
571
572 break;
573 }
574
575 *len_p = s - start;
576
577 if (LIKELY(! overflowed)) {
578 #if UVSIZE > 4
579 if ( UNLIKELY(value > 0xffffffff)
580 && ! (input_flags & PERL_SCAN_SILENT_NON_PORTABLE))
581 {
582 output_non_portable(base);
583 *flags |= PERL_SCAN_SILENT_NON_PORTABLE;
584 }
585 #endif
586 return value;
587 }
588
589 /* Overflowed: Calculate the final overflow approximation */
590 value_nv *= factor;
591 value_nv += (NV) value;
592
593 output_non_portable(base);
594
595 *flags |= PERL_SCAN_GREATER_THAN_UV_MAX
596 | PERL_SCAN_SILENT_NON_PORTABLE;
597 if (result)
598 *result = value_nv;
599 return UV_MAX;
600 }
601
602 /*
603 =for apidoc scan_bin
604
605 For backwards compatibility. Use C<grok_bin> instead.
606
607 =for apidoc scan_hex
608
609 For backwards compatibility. Use C<grok_hex> instead.
610
611 =for apidoc scan_oct
612
613 For backwards compatibility. Use C<grok_oct> instead.
614
615 =cut
616 */
617
618 NV
Perl_scan_bin(pTHX_ const char * start,STRLEN len,STRLEN * retlen)619 Perl_scan_bin(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
620 {
621 NV rnv;
622 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
623 const UV ruv = grok_bin (start, &len, &flags, &rnv);
624
625 PERL_ARGS_ASSERT_SCAN_BIN;
626
627 *retlen = len;
628 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
629 }
630
631 NV
Perl_scan_oct(pTHX_ const char * start,STRLEN len,STRLEN * retlen)632 Perl_scan_oct(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
633 {
634 NV rnv;
635 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
636 const UV ruv = grok_oct (start, &len, &flags, &rnv);
637
638 PERL_ARGS_ASSERT_SCAN_OCT;
639
640 *retlen = len;
641 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
642 }
643
644 NV
Perl_scan_hex(pTHX_ const char * start,STRLEN len,STRLEN * retlen)645 Perl_scan_hex(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
646 {
647 NV rnv;
648 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
649 const UV ruv = grok_hex (start, &len, &flags, &rnv);
650
651 PERL_ARGS_ASSERT_SCAN_HEX;
652
653 *retlen = len;
654 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
655 }
656
657 /*
658 =for apidoc grok_numeric_radix
659
660 Scan and skip for a numeric decimal separator (radix).
661
662 =cut
663 */
664 bool
Perl_grok_numeric_radix(pTHX_ const char ** sp,const char * send)665 Perl_grok_numeric_radix(pTHX_ const char **sp, const char *send)
666 {
667 PERL_ARGS_ASSERT_GROK_NUMERIC_RADIX;
668
669 #ifdef USE_LOCALE_NUMERIC
670
671 if (IN_LC(LC_NUMERIC)) {
672 STRLEN len;
673 char * radix;
674 bool matches_radix = FALSE;
675 DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
676
677 STORE_LC_NUMERIC_FORCE_TO_UNDERLYING();
678
679 radix = SvPV(PL_numeric_radix_sv, len);
680 radix = savepvn(radix, len);
681
682 RESTORE_LC_NUMERIC();
683
684 if (*sp + len <= send) {
685 matches_radix = memEQ(*sp, radix, len);
686 }
687
688 Safefree(radix);
689
690 if (matches_radix) {
691 *sp += len;
692 return TRUE;
693 }
694 }
695
696 #endif
697
698 /* always try "." if numeric radix didn't match because
699 * we may have data from different locales mixed */
700 if (*sp < send && **sp == '.') {
701 ++*sp;
702 return TRUE;
703 }
704
705 return FALSE;
706 }
707
708 /*
709 =for apidoc grok_infnan
710
711 Helper for C<grok_number()>, accepts various ways of spelling "infinity"
712 or "not a number", and returns one of the following flag combinations:
713
714 IS_NUMBER_INFINITY
715 IS_NUMBER_NAN
716 IS_NUMBER_INFINITY | IS_NUMBER_NEG
717 IS_NUMBER_NAN | IS_NUMBER_NEG
718 0
719
720 possibly |-ed with C<IS_NUMBER_TRAILING>.
721
722 If an infinity or a not-a-number is recognized, C<*sp> will point to
723 one byte past the end of the recognized string. If the recognition fails,
724 zero is returned, and C<*sp> will not move.
725
726 =for apidoc Amnh|bool|IS_NUMBER_GREATER_THAN_UV_MAX
727 =for apidoc Amnh|bool|IS_NUMBER_INFINITY
728 =for apidoc Amnh|bool|IS_NUMBER_IN_UV
729 =for apidoc Amnh|bool|IS_NUMBER_NAN
730 =for apidoc Amnh|bool|IS_NUMBER_NEG
731 =for apidoc Amnh|bool|IS_NUMBER_NOT_INT
732
733 =cut
734 */
735
736 int
Perl_grok_infnan(pTHX_ const char ** sp,const char * send)737 Perl_grok_infnan(pTHX_ const char** sp, const char* send)
738 {
739 const char* s = *sp;
740 int flags = 0;
741 #if defined(NV_INF) || defined(NV_NAN)
742 bool odh = FALSE; /* one-dot-hash: 1.#INF */
743
744 PERL_ARGS_ASSERT_GROK_INFNAN;
745
746 if (*s == '+') {
747 s++; if (s == send) return 0;
748 }
749 else if (*s == '-') {
750 flags |= IS_NUMBER_NEG; /* Yes, -NaN happens. Incorrect but happens. */
751 s++; if (s == send) return 0;
752 }
753
754 if (*s == '1') {
755 /* Visual C: 1.#SNAN, -1.#QNAN, 1#INF, 1.#IND (maybe also 1.#NAN)
756 * Let's keep the dot optional. */
757 s++; if (s == send) return 0;
758 if (*s == '.') {
759 s++; if (s == send) return 0;
760 }
761 if (*s == '#') {
762 s++; if (s == send) return 0;
763 } else
764 return 0;
765 odh = TRUE;
766 }
767
768 if (isALPHA_FOLD_EQ(*s, 'I')) {
769 /* INF or IND (1.#IND is "indeterminate", a certain type of NAN) */
770
771 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return 0;
772 s++; if (s == send) return 0;
773 if (isALPHA_FOLD_EQ(*s, 'F')) {
774 s++;
775 if (s < send && (isALPHA_FOLD_EQ(*s, 'I'))) {
776 int fail =
777 flags | IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT | IS_NUMBER_TRAILING;
778 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return fail;
779 s++; if (s == send || isALPHA_FOLD_NE(*s, 'I')) return fail;
780 s++; if (s == send || isALPHA_FOLD_NE(*s, 'T')) return fail;
781 s++; if (s == send || isALPHA_FOLD_NE(*s, 'Y')) return fail;
782 s++;
783 } else if (odh) {
784 while (s < send && *s == '0') { /* 1.#INF00 */
785 s++;
786 }
787 }
788 while (s < send && isSPACE(*s))
789 s++;
790 if (s < send && *s) {
791 flags |= IS_NUMBER_TRAILING;
792 }
793 flags |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT;
794 }
795 else if (isALPHA_FOLD_EQ(*s, 'D') && odh) { /* 1.#IND */
796 s++;
797 flags |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
798 while (s < send && *s == '0') { /* 1.#IND00 */
799 s++;
800 }
801 if (s < send && *s) {
802 flags |= IS_NUMBER_TRAILING;
803 }
804 } else
805 return 0;
806 }
807 else {
808 /* Maybe NAN of some sort */
809
810 if (isALPHA_FOLD_EQ(*s, 'S') || isALPHA_FOLD_EQ(*s, 'Q')) {
811 /* snan, qNaN */
812 /* XXX do something with the snan/qnan difference */
813 s++; if (s == send) return 0;
814 }
815
816 if (isALPHA_FOLD_EQ(*s, 'N')) {
817 s++; if (s == send || isALPHA_FOLD_NE(*s, 'A')) return 0;
818 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return 0;
819 s++;
820
821 flags |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
822 if (s == send) {
823 return flags;
824 }
825
826 /* NaN can be followed by various stuff (NaNQ, NaNS), but
827 * there are also multiple different NaN values, and some
828 * implementations output the "payload" values,
829 * e.g. NaN123, NAN(abc), while some legacy implementations
830 * have weird stuff like NaN%. */
831 if (isALPHA_FOLD_EQ(*s, 'q') ||
832 isALPHA_FOLD_EQ(*s, 's')) {
833 /* "nanq" or "nans" are ok, though generating
834 * these portably is tricky. */
835 s++;
836 if (s == send) {
837 return flags;
838 }
839 }
840 if (*s == '(') {
841 /* C99 style "nan(123)" or Perlish equivalent "nan($uv)". */
842 const char *t;
843 s++;
844 if (s == send) {
845 return flags | IS_NUMBER_TRAILING;
846 }
847 t = s + 1;
848 while (t < send && *t && *t != ')') {
849 t++;
850 }
851 if (t == send) {
852 return flags | IS_NUMBER_TRAILING;
853 }
854 if (*t == ')') {
855 int nantype;
856 UV nanval;
857 if (s[0] == '0' && s + 2 < t &&
858 isALPHA_FOLD_EQ(s[1], 'x') &&
859 isXDIGIT(s[2])) {
860 STRLEN len = t - s;
861 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES;
862 nanval = grok_hex(s, &len, &flags, NULL);
863 if ((flags & PERL_SCAN_GREATER_THAN_UV_MAX)) {
864 nantype = 0;
865 } else {
866 nantype = IS_NUMBER_IN_UV;
867 }
868 s += len;
869 } else if (s[0] == '0' && s + 2 < t &&
870 isALPHA_FOLD_EQ(s[1], 'b') &&
871 (s[2] == '0' || s[2] == '1')) {
872 STRLEN len = t - s;
873 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES;
874 nanval = grok_bin(s, &len, &flags, NULL);
875 if ((flags & PERL_SCAN_GREATER_THAN_UV_MAX)) {
876 nantype = 0;
877 } else {
878 nantype = IS_NUMBER_IN_UV;
879 }
880 s += len;
881 } else {
882 const char *u;
883 nantype =
884 grok_number_flags(s, t - s, &nanval,
885 PERL_SCAN_TRAILING |
886 PERL_SCAN_ALLOW_UNDERSCORES);
887 /* Unfortunately grok_number_flags() doesn't
888 * tell how far we got and the ')' will always
889 * be "trailing", so we need to double-check
890 * whether we had something dubious. */
891 for (u = s; u < t; u++) {
892 if (!isDIGIT(*u)) {
893 flags |= IS_NUMBER_TRAILING;
894 break;
895 }
896 }
897 s = u;
898 }
899
900 /* XXX Doesn't do octal: nan("0123").
901 * Probably not a big loss. */
902
903 if ((nantype & IS_NUMBER_NOT_INT) ||
904 !(nantype && IS_NUMBER_IN_UV)) {
905 /* XXX the nanval is currently unused, that is,
906 * not inserted as the NaN payload of the NV.
907 * But the above code already parses the C99
908 * nan(...) format. See below, and see also
909 * the nan() in POSIX.xs.
910 *
911 * Certain configuration combinations where
912 * NVSIZE is greater than UVSIZE mean that
913 * a single UV cannot contain all the possible
914 * NaN payload bits. There would need to be
915 * some more generic syntax than "nan($uv)".
916 *
917 * Issues to keep in mind:
918 *
919 * (1) In most common cases there would
920 * not be an integral number of bytes that
921 * could be set, only a certain number of bits.
922 * For example for the common case of
923 * NVSIZE == UVSIZE == 8 there is room for 52
924 * bits in the payload, but the most significant
925 * bit is commonly reserved for the
926 * signaling/quiet bit, leaving 51 bits.
927 * Furthermore, the C99 nan() is supposed
928 * to generate quiet NaNs, so it is doubtful
929 * whether it should be able to generate
930 * signaling NaNs. For the x86 80-bit doubles
931 * (if building a long double Perl) there would
932 * be 62 bits (s/q bit being the 63rd).
933 *
934 * (2) Endianness of the payload bits. If the
935 * payload is specified as an UV, the low-order
936 * bits of the UV are naturally little-endianed
937 * (rightmost) bits of the payload. The endianness
938 * of UVs and NVs can be different. */
939 return 0;
940 }
941 if (s < t) {
942 flags |= IS_NUMBER_TRAILING;
943 }
944 } else {
945 /* Looked like nan(...), but no close paren. */
946 flags |= IS_NUMBER_TRAILING;
947 }
948 } else {
949 while (s < send && isSPACE(*s))
950 s++;
951 if (s < send && *s) {
952 /* Note that we here implicitly accept (parse as
953 * "nan", but with warnings) also any other weird
954 * trailing stuff for "nan". In the above we just
955 * check that if we got the C99-style "nan(...)",
956 * the "..." looks sane.
957 * If in future we accept more ways of specifying
958 * the nan payload, the accepting would happen around
959 * here. */
960 flags |= IS_NUMBER_TRAILING;
961 }
962 }
963 s = send;
964 }
965 else
966 return 0;
967 }
968
969 while (s < send && isSPACE(*s))
970 s++;
971
972 #else
973 PERL_UNUSED_ARG(send);
974 #endif /* #if defined(NV_INF) || defined(NV_NAN) */
975 *sp = s;
976 return flags;
977 }
978
979 /*
980 =for apidoc grok_number_flags
981
982 Recognise (or not) a number. The type of the number is returned
983 (0 if unrecognised), otherwise it is a bit-ORed combination of
984 C<IS_NUMBER_IN_UV>, C<IS_NUMBER_GREATER_THAN_UV_MAX>, C<IS_NUMBER_NOT_INT>,
985 C<IS_NUMBER_NEG>, C<IS_NUMBER_INFINITY>, C<IS_NUMBER_NAN> (defined in perl.h).
986
987 If the value of the number can fit in a UV, it is returned in C<*valuep>.
988 C<IS_NUMBER_IN_UV> will be set to indicate that C<*valuep> is valid, C<IS_NUMBER_IN_UV>
989 will never be set unless C<*valuep> is valid, but C<*valuep> may have been assigned
990 to during processing even though C<IS_NUMBER_IN_UV> is not set on return.
991 If C<valuep> is C<NULL>, C<IS_NUMBER_IN_UV> will be set for the same cases as when
992 C<valuep> is non-C<NULL>, but no actual assignment (or SEGV) will occur.
993
994 C<IS_NUMBER_NOT_INT> will be set with C<IS_NUMBER_IN_UV> if trailing decimals were
995 seen (in which case C<*valuep> gives the true value truncated to an integer), and
996 C<IS_NUMBER_NEG> if the number is negative (in which case C<*valuep> holds the
997 absolute value). C<IS_NUMBER_IN_UV> is not set if C<e> notation was used or the
998 number is larger than a UV.
999
1000 C<flags> allows only C<PERL_SCAN_TRAILING>, which allows for trailing
1001 non-numeric text on an otherwise successful I<grok>, setting
1002 C<IS_NUMBER_TRAILING> on the result.
1003
1004 =for apidoc Amnh||PERL_SCAN_TRAILING
1005
1006 =for apidoc grok_number
1007
1008 Identical to C<grok_number_flags()> with C<flags> set to zero.
1009
1010 =cut
1011 */
1012 int
Perl_grok_number(pTHX_ const char * pv,STRLEN len,UV * valuep)1013 Perl_grok_number(pTHX_ const char *pv, STRLEN len, UV *valuep)
1014 {
1015 PERL_ARGS_ASSERT_GROK_NUMBER;
1016
1017 return grok_number_flags(pv, len, valuep, 0);
1018 }
1019
1020 static const UV uv_max_div_10 = UV_MAX / 10;
1021 static const U8 uv_max_mod_10 = UV_MAX % 10;
1022
1023 int
Perl_grok_number_flags(pTHX_ const char * pv,STRLEN len,UV * valuep,U32 flags)1024 Perl_grok_number_flags(pTHX_ const char *pv, STRLEN len, UV *valuep, U32 flags)
1025 {
1026 const char *s = pv;
1027 const char * const send = pv + len;
1028 const char *d;
1029 int numtype = 0;
1030
1031 PERL_ARGS_ASSERT_GROK_NUMBER_FLAGS;
1032
1033 if (UNLIKELY(isSPACE(*s))) {
1034 s++;
1035 while (s < send) {
1036 if (LIKELY(! isSPACE(*s))) goto non_space;
1037 s++;
1038 }
1039 return 0;
1040 non_space: ;
1041 }
1042
1043 /* See if signed. This assumes it is more likely to be unsigned, so
1044 * penalizes signed by an extra conditional; rewarding unsigned by one fewer
1045 * (because we detect '+' and '-' with a single test and then add a
1046 * conditional to determine which) */
1047 if (UNLIKELY((*s & ~('+' ^ '-')) == ('+' & '-') )) {
1048
1049 /* Here, on ASCII platforms, *s is one of: 0x29 = ')', 2B = '+', 2D = '-',
1050 * 2F = '/'. That is, it is either a sign, or a character that doesn't
1051 * belong in a number at all (unless it's a radix character in a weird
1052 * locale). Given this, it's far more likely to be a minus than the
1053 * others. (On EBCDIC it is one of 42, 44, 46, 48, 4A, 4C, 4E, (not 40
1054 * because can't be a space) 60, 62, 64, 66, 68, 6A, 6C, 6E. Again,
1055 * only potentially a weird radix character, or 4E='+', or 60='-') */
1056 if (LIKELY(*s == '-')) {
1057 s++;
1058 numtype = IS_NUMBER_NEG;
1059 }
1060 else if (LIKELY(*s == '+'))
1061 s++;
1062 else /* Can't just return failure here, as it could be a weird radix
1063 character */
1064 goto done_sign;
1065
1066 if (UNLIKELY(s == send))
1067 return 0;
1068 done_sign: ;
1069 }
1070
1071 /* The first digit (after optional sign): note that might
1072 * also point to "infinity" or "nan", or "1.#INF". */
1073 d = s;
1074
1075 /* next must be digit or the radix separator or beginning of infinity/nan */
1076 if (LIKELY(isDIGIT(*s))) {
1077 /* UVs are at least 32 bits, so the first 9 decimal digits cannot
1078 overflow. */
1079 UV value = *s - '0'; /* Process this first (perhaps only) digit */
1080 int digit;
1081
1082 s++;
1083
1084 switch(send - s) {
1085 default: /* 8 or more remaining characters */
1086 digit = *s - '0';
1087 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1088 value = value * 10 + digit;
1089 s++;
1090 /* FALLTHROUGH */
1091 case 7:
1092 digit = *s - '0';
1093 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1094 value = value * 10 + digit;
1095 s++;
1096 /* FALLTHROUGH */
1097 case 6:
1098 digit = *s - '0';
1099 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1100 value = value * 10 + digit;
1101 s++;
1102 /* FALLTHROUGH */
1103 case 5:
1104 digit = *s - '0';
1105 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1106 value = value * 10 + digit;
1107 s++;
1108 /* FALLTHROUGH */
1109 case 4:
1110 digit = *s - '0';
1111 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1112 value = value * 10 + digit;
1113 s++;
1114 /* FALLTHROUGH */
1115 case 3:
1116 digit = *s - '0';
1117 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1118 value = value * 10 + digit;
1119 s++;
1120 /* FALLTHROUGH */
1121 case 2:
1122 digit = *s - '0';
1123 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1124 value = value * 10 + digit;
1125 s++;
1126 /* FALLTHROUGH */
1127 case 1:
1128 digit = *s - '0';
1129 if (UNLIKELY(! inRANGE(digit, 0, 9))) break;
1130 value = value * 10 + digit;
1131 s++;
1132 /* FALLTHROUGH */
1133 case 0: /* This case means the string consists of just the one
1134 digit we already have processed */
1135
1136 /* If we got here by falling through other than the default: case, we
1137 * have processed the whole string, and know it consists entirely of
1138 * digits, and can't have overflowed. */
1139 if (s >= send) {
1140 if (valuep)
1141 *valuep = value;
1142 return numtype|IS_NUMBER_IN_UV;
1143 }
1144
1145 /* Here, there are extra characters beyond the first 9 digits. Use a
1146 * loop to accumulate any remaining digits, until we get a non-digit or
1147 * would overflow. Note that leading zeros could cause us to get here
1148 * without being close to overflowing.
1149 *
1150 * (The conditional 's >= send' above could be eliminated by making the
1151 * default: in the switch to instead be 'case 8:', and process longer
1152 * strings separately by using the loop below. This would penalize
1153 * these inputs by the extra instructions needed for looping. That
1154 * could be eliminated by copying the unwound code from above to handle
1155 * the firt 9 digits of these. khw didn't think this saving of a
1156 * single conditional was worth it.) */
1157 do {
1158 digit = *s - '0';
1159 if (! inRANGE(digit, 0, 9)) goto mantissa_done;
1160 if ( value < uv_max_div_10
1161 || ( value == uv_max_div_10
1162 && digit <= uv_max_mod_10))
1163 {
1164 value = value * 10 + digit;
1165 s++;
1166 }
1167 else { /* value would overflow. skip the remaining digits, don't
1168 worry about setting *valuep. */
1169 do {
1170 s++;
1171 } while (s < send && isDIGIT(*s));
1172 numtype |=
1173 IS_NUMBER_GREATER_THAN_UV_MAX;
1174 goto skip_value;
1175 }
1176 } while (s < send);
1177 } /* End switch on input length */
1178
1179 mantissa_done:
1180 numtype |= IS_NUMBER_IN_UV;
1181 if (valuep)
1182 *valuep = value;
1183
1184 skip_value:
1185 if (GROK_NUMERIC_RADIX(&s, send)) {
1186 numtype |= IS_NUMBER_NOT_INT;
1187 while (s < send && isDIGIT(*s)) /* optional digits after the radix */
1188 s++;
1189 }
1190 } /* End of *s is a digit */
1191 else if (GROK_NUMERIC_RADIX(&s, send)) {
1192 numtype |= IS_NUMBER_NOT_INT | IS_NUMBER_IN_UV; /* valuep assigned below */
1193 /* no digits before the radix means we need digits after it */
1194 if (s < send && isDIGIT(*s)) {
1195 do {
1196 s++;
1197 } while (s < send && isDIGIT(*s));
1198 if (valuep) {
1199 /* integer approximation is valid - it's 0. */
1200 *valuep = 0;
1201 }
1202 }
1203 else
1204 return 0;
1205 }
1206
1207 if (LIKELY(s > d) && s < send) {
1208 /* we can have an optional exponent part */
1209 if (UNLIKELY(isALPHA_FOLD_EQ(*s, 'e'))) {
1210 s++;
1211 if (s < send && (*s == '-' || *s == '+'))
1212 s++;
1213 if (s < send && isDIGIT(*s)) {
1214 do {
1215 s++;
1216 } while (s < send && isDIGIT(*s));
1217 }
1218 else if (flags & PERL_SCAN_TRAILING)
1219 return numtype | IS_NUMBER_TRAILING;
1220 else
1221 return 0;
1222
1223 /* The only flag we keep is sign. Blow away any "it's UV" */
1224 numtype &= IS_NUMBER_NEG;
1225 numtype |= IS_NUMBER_NOT_INT;
1226 }
1227 }
1228
1229 while (s < send) {
1230 if (LIKELY(! isSPACE(*s))) goto end_space;
1231 s++;
1232 }
1233 return numtype;
1234
1235 end_space:
1236
1237 if (UNLIKELY(memEQs(pv, len, "0 but true"))) {
1238 if (valuep)
1239 *valuep = 0;
1240 return IS_NUMBER_IN_UV;
1241 }
1242
1243 /* We could be e.g. at "Inf" or "NaN", or at the "#" of "1.#INF". */
1244 if ((s + 2 < send) && UNLIKELY(memCHRs("inqs#", toFOLD(*s)))) {
1245 /* Really detect inf/nan. Start at d, not s, since the above
1246 * code might have already consumed the "1." or "1". */
1247 const int infnan = Perl_grok_infnan(aTHX_ &d, send);
1248 if ((infnan & IS_NUMBER_INFINITY)) {
1249 return (numtype | infnan); /* Keep sign for infinity. */
1250 }
1251 else if ((infnan & IS_NUMBER_NAN)) {
1252 return (numtype | infnan) & ~IS_NUMBER_NEG; /* Clear sign for nan. */
1253 }
1254 }
1255 else if (flags & PERL_SCAN_TRAILING) {
1256 return numtype | IS_NUMBER_TRAILING;
1257 }
1258
1259 return 0;
1260 }
1261
1262 /*
1263 =for apidoc grok_atoUV
1264
1265 parse a string, looking for a decimal unsigned integer.
1266
1267 On entry, C<pv> points to the beginning of the string;
1268 C<valptr> points to a UV that will receive the converted value, if found;
1269 C<endptr> is either NULL or points to a variable that points to one byte
1270 beyond the point in C<pv> that this routine should examine.
1271 If C<endptr> is NULL, C<pv> is assumed to be NUL-terminated.
1272
1273 Returns FALSE if C<pv> doesn't represent a valid unsigned integer value (with
1274 no leading zeros). Otherwise it returns TRUE, and sets C<*valptr> to that
1275 value.
1276
1277 If you constrain the portion of C<pv> that is looked at by this function (by
1278 passing a non-NULL C<endptr>), and if the intial bytes of that portion form a
1279 valid value, it will return TRUE, setting C<*endptr> to the byte following the
1280 final digit of the value. But if there is no constraint at what's looked at,
1281 all of C<pv> must be valid in order for TRUE to be returned. C<*endptr> is
1282 unchanged from its value on input if FALSE is returned;
1283
1284 The only characters this accepts are the decimal digits '0'..'9'.
1285
1286 As opposed to L<atoi(3)> or L<strtol(3)>, C<grok_atoUV> does NOT allow optional
1287 leading whitespace, nor negative inputs. If such features are required, the
1288 calling code needs to explicitly implement those.
1289
1290 Note that this function returns FALSE for inputs that would overflow a UV,
1291 or have leading zeros. Thus a single C<0> is accepted, but not C<00> nor
1292 C<01>, C<002>, I<etc>.
1293
1294 Background: C<atoi> has severe problems with illegal inputs, it cannot be
1295 used for incremental parsing, and therefore should be avoided
1296 C<atoi> and C<strtol> are also affected by locale settings, which can also be
1297 seen as a bug (global state controlled by user environment).
1298
1299 =cut
1300
1301 */
1302
1303 bool
Perl_grok_atoUV(const char * pv,UV * valptr,const char ** endptr)1304 Perl_grok_atoUV(const char *pv, UV *valptr, const char** endptr)
1305 {
1306 const char* s = pv;
1307 const char** eptr;
1308 const char* end2; /* Used in case endptr is NULL. */
1309 UV val = 0; /* The parsed value. */
1310
1311 PERL_ARGS_ASSERT_GROK_ATOUV;
1312
1313 if (endptr) {
1314 eptr = endptr;
1315 }
1316 else {
1317 end2 = s + strlen(s);
1318 eptr = &end2;
1319 }
1320
1321 if ( *eptr <= s
1322 || ! isDIGIT(*s))
1323 {
1324 return FALSE;
1325 }
1326
1327 /* Single-digit inputs are quite common. */
1328 val = *s++ - '0';
1329 if (s < *eptr && isDIGIT(*s)) {
1330 /* Fail on extra leading zeros. */
1331 if (val == 0)
1332 return FALSE;
1333 while (s < *eptr && isDIGIT(*s)) {
1334 /* This could be unrolled like in grok_number(), but
1335 * the expected uses of this are not speed-needy, and
1336 * unlikely to need full 64-bitness. */
1337 const U8 digit = *s++ - '0';
1338 if (val < uv_max_div_10 ||
1339 (val == uv_max_div_10 && digit <= uv_max_mod_10)) {
1340 val = val * 10 + digit;
1341 } else {
1342 return FALSE;
1343 }
1344 }
1345 }
1346
1347 if (endptr == NULL) {
1348 if (*s) {
1349 return FALSE; /* If endptr is NULL, no trailing non-digits allowed. */
1350 }
1351 }
1352 else {
1353 *endptr = s;
1354 }
1355
1356 *valptr = val;
1357 return TRUE;
1358 }
1359
1360 #ifndef Perl_strtod
1361 STATIC NV
S_mulexp10(NV value,I32 exponent)1362 S_mulexp10(NV value, I32 exponent)
1363 {
1364 NV result = 1.0;
1365 NV power = 10.0;
1366 bool negative = 0;
1367 I32 bit;
1368
1369 if (exponent == 0)
1370 return value;
1371 if (value == 0)
1372 return (NV)0;
1373
1374 /* On OpenVMS VAX we by default use the D_FLOAT double format,
1375 * and that format does not have *easy* capabilities [1] for
1376 * overflowing doubles 'silently' as IEEE fp does. We also need
1377 * to support G_FLOAT on both VAX and Alpha, and though the exponent
1378 * range is much larger than D_FLOAT it still doesn't do silent
1379 * overflow. Therefore we need to detect early whether we would
1380 * overflow (this is the behaviour of the native string-to-float
1381 * conversion routines, and therefore of native applications, too).
1382 *
1383 * [1] Trying to establish a condition handler to trap floating point
1384 * exceptions is not a good idea. */
1385
1386 /* In UNICOS and in certain Cray models (such as T90) there is no
1387 * IEEE fp, and no way at all from C to catch fp overflows gracefully.
1388 * There is something you can do if you are willing to use some
1389 * inline assembler: the instruction is called DFI-- but that will
1390 * disable *all* floating point interrupts, a little bit too large
1391 * a hammer. Therefore we need to catch potential overflows before
1392 * it's too late. */
1393
1394 #if ((defined(VMS) && !defined(_IEEE_FP)) || defined(_UNICOS) || defined(DOUBLE_IS_VAX_FLOAT)) && defined(NV_MAX_10_EXP)
1395 STMT_START {
1396 const NV exp_v = log10(value);
1397 if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP)
1398 return NV_MAX;
1399 if (exponent < 0) {
1400 if (-(exponent + exp_v) >= NV_MAX_10_EXP)
1401 return 0.0;
1402 while (-exponent >= NV_MAX_10_EXP) {
1403 /* combination does not overflow, but 10^(-exponent) does */
1404 value /= 10;
1405 ++exponent;
1406 }
1407 }
1408 } STMT_END;
1409 #endif
1410
1411 if (exponent < 0) {
1412 negative = 1;
1413 exponent = -exponent;
1414 #ifdef NV_MAX_10_EXP
1415 /* for something like 1234 x 10^-309, the action of calculating
1416 * the intermediate value 10^309 then returning 1234 / (10^309)
1417 * will fail, since 10^309 becomes infinity. In this case try to
1418 * refactor it as 123 / (10^308) etc.
1419 */
1420 while (value && exponent > NV_MAX_10_EXP) {
1421 exponent--;
1422 value /= 10;
1423 }
1424 if (value == 0.0)
1425 return value;
1426 #endif
1427 }
1428 #if defined(__osf__)
1429 /* Even with cc -ieee + ieee_set_fp_control(IEEE_TRAP_ENABLE_INV)
1430 * Tru64 fp behavior on inf/nan is somewhat broken. Another way
1431 * to do this would be ieee_set_fp_control(IEEE_TRAP_ENABLE_OVF)
1432 * but that breaks another set of infnan.t tests. */
1433 # define FP_OVERFLOWS_TO_ZERO
1434 #endif
1435 for (bit = 1; exponent; bit <<= 1) {
1436 if (exponent & bit) {
1437 exponent ^= bit;
1438 result *= power;
1439 #ifdef FP_OVERFLOWS_TO_ZERO
1440 if (result == 0)
1441 # ifdef NV_INF
1442 return value < 0 ? -NV_INF : NV_INF;
1443 # else
1444 return value < 0 ? -FLT_MAX : FLT_MAX;
1445 # endif
1446 #endif
1447 /* Floating point exceptions are supposed to be turned off,
1448 * but if we're obviously done, don't risk another iteration.
1449 */
1450 if (exponent == 0) break;
1451 }
1452 power *= power;
1453 }
1454 return negative ? value / result : value * result;
1455 }
1456 #endif /* #ifndef Perl_strtod */
1457
1458 #ifdef Perl_strtod
1459 # define ATOF(s, x) my_atof2(s, &x)
1460 #else
1461 # define ATOF(s, x) Perl_atof2(s, x)
1462 #endif
1463
1464 NV
Perl_my_atof(pTHX_ const char * s)1465 Perl_my_atof(pTHX_ const char* s)
1466 {
1467
1468 /*
1469 =for apidoc my_atof
1470
1471 L<C<atof>(3)>, but properly works with Perl locale handling, accepting a dot
1472 radix character always, but also the current locale's radix character if and
1473 only if called from within the lexical scope of a Perl C<use locale> statement.
1474
1475 N.B. C<s> must be NUL terminated.
1476
1477 =cut
1478 */
1479
1480 NV x = 0.0;
1481
1482 PERL_ARGS_ASSERT_MY_ATOF;
1483
1484 #if ! defined(USE_LOCALE_NUMERIC)
1485
1486 ATOF(s, x);
1487
1488 #else
1489
1490 {
1491 DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
1492 STORE_LC_NUMERIC_SET_TO_NEEDED();
1493 if (! (PL_numeric_radix_sv && IN_LC(LC_NUMERIC))) {
1494 ATOF(s,x);
1495 }
1496 else {
1497
1498 /* Look through the string for the first thing that looks like a
1499 * decimal point: either the value in the current locale or the
1500 * standard fallback of '.'. The one which appears earliest in the
1501 * input string is the one that we should have atof look for. Note
1502 * that we have to determine this beforehand because on some
1503 * systems, Perl_atof2 is just a wrapper around the system's atof.
1504 * */
1505 const char * const standard_pos = strchr(s, '.');
1506 const char * const local_pos
1507 = strstr(s, SvPV_nolen(PL_numeric_radix_sv));
1508 const bool use_standard_radix
1509 = standard_pos && (!local_pos || standard_pos < local_pos);
1510
1511 if (use_standard_radix) {
1512 SET_NUMERIC_STANDARD();
1513 LOCK_LC_NUMERIC_STANDARD();
1514 }
1515
1516 ATOF(s,x);
1517
1518 if (use_standard_radix) {
1519 UNLOCK_LC_NUMERIC_STANDARD();
1520 SET_NUMERIC_UNDERLYING();
1521 }
1522 }
1523 RESTORE_LC_NUMERIC();
1524 }
1525
1526 #endif
1527
1528 return x;
1529 }
1530
1531 #if defined(NV_INF) || defined(NV_NAN)
1532
1533 static char*
S_my_atof_infnan(pTHX_ const char * s,bool negative,const char * send,NV * value)1534 S_my_atof_infnan(pTHX_ const char* s, bool negative, const char* send, NV* value)
1535 {
1536 const char *p0 = negative ? s - 1 : s;
1537 const char *p = p0;
1538 const int infnan = grok_infnan(&p, send);
1539 if (infnan && p != p0) {
1540 /* If we can generate inf/nan directly, let's do so. */
1541 #ifdef NV_INF
1542 if ((infnan & IS_NUMBER_INFINITY)) {
1543 *value = (infnan & IS_NUMBER_NEG) ? -NV_INF: NV_INF;
1544 return (char*)p;
1545 }
1546 #endif
1547 #ifdef NV_NAN
1548 if ((infnan & IS_NUMBER_NAN)) {
1549 *value = NV_NAN;
1550 return (char*)p;
1551 }
1552 #endif
1553 #ifdef Perl_strtod
1554 /* If still here, we didn't have either NV_INF or NV_NAN,
1555 * and can try falling back to native strtod/strtold.
1556 *
1557 * The native interface might not recognize all the possible
1558 * inf/nan strings Perl recognizes. What we can try
1559 * is to try faking the input. We will try inf/-inf/nan
1560 * as the most promising/portable input. */
1561 {
1562 const char* fake = "silence compiler warning";
1563 char* endp;
1564 NV nv;
1565 #ifdef NV_INF
1566 if ((infnan & IS_NUMBER_INFINITY)) {
1567 fake = ((infnan & IS_NUMBER_NEG)) ? "-inf" : "inf";
1568 }
1569 #endif
1570 #ifdef NV_NAN
1571 if ((infnan & IS_NUMBER_NAN)) {
1572 fake = "nan";
1573 }
1574 #endif
1575 assert(strNE(fake, "silence compiler warning"));
1576 nv = S_strtod(aTHX_ fake, &endp);
1577 if (fake != endp) {
1578 #ifdef NV_INF
1579 if ((infnan & IS_NUMBER_INFINITY)) {
1580 # ifdef Perl_isinf
1581 if (Perl_isinf(nv))
1582 *value = nv;
1583 # else
1584 /* last resort, may generate SIGFPE */
1585 *value = Perl_exp((NV)1e9);
1586 if ((infnan & IS_NUMBER_NEG))
1587 *value = -*value;
1588 # endif
1589 return (char*)p; /* p, not endp */
1590 }
1591 #endif
1592 #ifdef NV_NAN
1593 if ((infnan & IS_NUMBER_NAN)) {
1594 # ifdef Perl_isnan
1595 if (Perl_isnan(nv))
1596 *value = nv;
1597 # else
1598 /* last resort, may generate SIGFPE */
1599 *value = Perl_log((NV)-1.0);
1600 # endif
1601 return (char*)p; /* p, not endp */
1602 #endif
1603 }
1604 }
1605 }
1606 #endif /* #ifdef Perl_strtod */
1607 }
1608 return NULL;
1609 }
1610
1611 #endif /* if defined(NV_INF) || defined(NV_NAN) */
1612
1613 char*
Perl_my_atof2(pTHX_ const char * orig,NV * value)1614 Perl_my_atof2(pTHX_ const char* orig, NV* value)
1615 {
1616 PERL_ARGS_ASSERT_MY_ATOF2;
1617 return my_atof3(orig, value, 0);
1618 }
1619
1620 char*
Perl_my_atof3(pTHX_ const char * orig,NV * value,const STRLEN len)1621 Perl_my_atof3(pTHX_ const char* orig, NV* value, const STRLEN len)
1622 {
1623 const char* s = orig;
1624 NV result[3] = {0.0, 0.0, 0.0};
1625 #if defined(USE_PERL_ATOF) || defined(Perl_strtod)
1626 const char* send = s + ((len != 0)
1627 ? len
1628 : strlen(orig)); /* one past the last */
1629 bool negative = 0;
1630 #endif
1631 #if defined(USE_PERL_ATOF) && !defined(Perl_strtod)
1632 UV accumulator[2] = {0,0}; /* before/after dp */
1633 bool seen_digit = 0;
1634 I32 exp_adjust[2] = {0,0};
1635 I32 exp_acc[2] = {-1, -1};
1636 /* the current exponent adjust for the accumulators */
1637 I32 exponent = 0;
1638 I32 seen_dp = 0;
1639 I32 digit = 0;
1640 I32 old_digit = 0;
1641 I32 sig_digits = 0; /* noof significant digits seen so far */
1642 #endif
1643
1644 #if defined(USE_PERL_ATOF) || defined(Perl_strtod)
1645 PERL_ARGS_ASSERT_MY_ATOF3;
1646
1647 /* leading whitespace */
1648 while (s < send && isSPACE(*s))
1649 ++s;
1650
1651 /* sign */
1652 switch (*s) {
1653 case '-':
1654 negative = 1;
1655 /* FALLTHROUGH */
1656 case '+':
1657 ++s;
1658 }
1659 #endif
1660
1661 #ifdef Perl_strtod
1662 {
1663 char* endp;
1664 char* copy = NULL;
1665
1666 if ((endp = S_my_atof_infnan(aTHX_ s, negative, send, value)))
1667 return endp;
1668
1669 /* strtold() accepts 0x-prefixed hex and in POSIX implementations,
1670 0b-prefixed binary numbers, which is backward incompatible
1671 */
1672 if ((len == 0 || len - (s-orig) >= 2) && *s == '0' &&
1673 (isALPHA_FOLD_EQ(s[1], 'x') || isALPHA_FOLD_EQ(s[1], 'b'))) {
1674 *value = 0;
1675 return (char *)s+1;
1676 }
1677
1678 /* If the length is passed in, the input string isn't NUL-terminated,
1679 * and in it turns out the function below assumes it is; therefore we
1680 * create a copy and NUL-terminate that */
1681 if (len) {
1682 Newx(copy, len + 1, char);
1683 Copy(orig, copy, len, char);
1684 copy[len] = '\0';
1685 s = copy + (s - orig);
1686 }
1687
1688 result[2] = S_strtod(aTHX_ s, &endp);
1689
1690 /* If we created a copy, 'endp' is in terms of that. Convert back to
1691 * the original */
1692 if (copy) {
1693 s = (s - copy) + (char *) orig;
1694 endp = (endp - copy) + (char *) orig;
1695 Safefree(copy);
1696 }
1697
1698 if (s != endp) {
1699 *value = negative ? -result[2] : result[2];
1700 return endp;
1701 }
1702 return NULL;
1703 }
1704 #elif defined(USE_PERL_ATOF)
1705
1706 /* There is no point in processing more significant digits
1707 * than the NV can hold. Note that NV_DIG is a lower-bound value,
1708 * while we need an upper-bound value. We add 2 to account for this;
1709 * since it will have been conservative on both the first and last digit.
1710 * For example a 32-bit mantissa with an exponent of 4 would have
1711 * exact values in the set
1712 * 4
1713 * 8
1714 * ..
1715 * 17179869172
1716 * 17179869176
1717 * 17179869180
1718 *
1719 * where for the purposes of calculating NV_DIG we would have to discount
1720 * both the first and last digit, since neither can hold all values from
1721 * 0..9; but for calculating the value we must examine those two digits.
1722 */
1723 #ifdef MAX_SIG_DIG_PLUS
1724 /* It is not necessarily the case that adding 2 to NV_DIG gets all the
1725 possible digits in a NV, especially if NVs are not IEEE compliant
1726 (e.g., long doubles on IRIX) - Allen <allens@cpan.org> */
1727 # define MAX_SIG_DIGITS (NV_DIG+MAX_SIG_DIG_PLUS)
1728 #else
1729 # define MAX_SIG_DIGITS (NV_DIG+2)
1730 #endif
1731
1732 /* the max number we can accumulate in a UV, and still safely do 10*N+9 */
1733 #define MAX_ACCUMULATE ( (UV) ((UV_MAX - 9)/10))
1734
1735 #if defined(NV_INF) || defined(NV_NAN)
1736 {
1737 char* endp;
1738 if ((endp = S_my_atof_infnan(aTHX_ s, negative, send, value)))
1739 return endp;
1740 }
1741 #endif
1742
1743 /* we accumulate digits into an integer; when this becomes too
1744 * large, we add the total to NV and start again */
1745
1746 while (s < send) {
1747 if (isDIGIT(*s)) {
1748 seen_digit = 1;
1749 old_digit = digit;
1750 digit = *s++ - '0';
1751 if (seen_dp)
1752 exp_adjust[1]++;
1753
1754 /* don't start counting until we see the first significant
1755 * digit, eg the 5 in 0.00005... */
1756 if (!sig_digits && digit == 0)
1757 continue;
1758
1759 if (++sig_digits > MAX_SIG_DIGITS) {
1760 /* limits of precision reached */
1761 if (digit > 5) {
1762 ++accumulator[seen_dp];
1763 } else if (digit == 5) {
1764 if (old_digit % 2) { /* round to even - Allen */
1765 ++accumulator[seen_dp];
1766 }
1767 }
1768 if (seen_dp) {
1769 exp_adjust[1]--;
1770 } else {
1771 exp_adjust[0]++;
1772 }
1773 /* skip remaining digits */
1774 while (s < send && isDIGIT(*s)) {
1775 ++s;
1776 if (! seen_dp) {
1777 exp_adjust[0]++;
1778 }
1779 }
1780 /* warn of loss of precision? */
1781 }
1782 else {
1783 if (accumulator[seen_dp] > MAX_ACCUMULATE) {
1784 /* add accumulator to result and start again */
1785 result[seen_dp] = S_mulexp10(result[seen_dp],
1786 exp_acc[seen_dp])
1787 + (NV)accumulator[seen_dp];
1788 accumulator[seen_dp] = 0;
1789 exp_acc[seen_dp] = 0;
1790 }
1791 accumulator[seen_dp] = accumulator[seen_dp] * 10 + digit;
1792 ++exp_acc[seen_dp];
1793 }
1794 }
1795 else if (!seen_dp && GROK_NUMERIC_RADIX(&s, send)) {
1796 seen_dp = 1;
1797 if (sig_digits > MAX_SIG_DIGITS) {
1798 while (s < send && isDIGIT(*s)) {
1799 ++s;
1800 }
1801 break;
1802 }
1803 }
1804 else {
1805 break;
1806 }
1807 }
1808
1809 result[0] = S_mulexp10(result[0], exp_acc[0]) + (NV)accumulator[0];
1810 if (seen_dp) {
1811 result[1] = S_mulexp10(result[1], exp_acc[1]) + (NV)accumulator[1];
1812 }
1813
1814 if (s < send && seen_digit && (isALPHA_FOLD_EQ(*s, 'e'))) {
1815 bool expnegative = 0;
1816
1817 ++s;
1818 switch (*s) {
1819 case '-':
1820 expnegative = 1;
1821 /* FALLTHROUGH */
1822 case '+':
1823 ++s;
1824 }
1825 while (s < send && isDIGIT(*s))
1826 exponent = exponent * 10 + (*s++ - '0');
1827 if (expnegative)
1828 exponent = -exponent;
1829 }
1830
1831 /* now apply the exponent */
1832
1833 if (seen_dp) {
1834 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0])
1835 + S_mulexp10(result[1],exponent-exp_adjust[1]);
1836 } else {
1837 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]);
1838 }
1839
1840 /* now apply the sign */
1841 if (negative)
1842 result[2] = -result[2];
1843 *value = result[2];
1844 return (char *)s;
1845 #else /* USE_PERL_ATOF */
1846 /* If you see this error you both don't have strtod (or configured -Ud_strtod or
1847 or it's long double/quadmath equivalent) and disabled USE_PERL_ATOF, thus
1848 removing any way for perl to convert strings to floating point numbers.
1849 */
1850 # error No mechanism to convert strings to numbers available
1851 #endif
1852 }
1853
1854 /*
1855 =for apidoc isinfnan
1856
1857 C<Perl_isinfnan()> is a utility function that returns true if the NV
1858 argument is either an infinity or a C<NaN>, false otherwise. To test
1859 in more detail, use C<Perl_isinf()> and C<Perl_isnan()>.
1860
1861 This is also the logical inverse of Perl_isfinite().
1862
1863 =cut
1864 */
1865 bool
Perl_isinfnan(NV nv)1866 Perl_isinfnan(NV nv)
1867 {
1868 PERL_UNUSED_ARG(nv);
1869 #ifdef Perl_isinf
1870 if (Perl_isinf(nv))
1871 return TRUE;
1872 #endif
1873 #ifdef Perl_isnan
1874 if (Perl_isnan(nv))
1875 return TRUE;
1876 #endif
1877 return FALSE;
1878 }
1879
1880 /*
1881 =for apidoc isinfnansv
1882
1883 Checks whether the argument would be either an infinity or C<NaN> when used
1884 as a number, but is careful not to trigger non-numeric or uninitialized
1885 warnings. it assumes the caller has done C<SvGETMAGIC(sv)> already.
1886
1887 =cut
1888 */
1889
1890 bool
Perl_isinfnansv(pTHX_ SV * sv)1891 Perl_isinfnansv(pTHX_ SV *sv)
1892 {
1893 PERL_ARGS_ASSERT_ISINFNANSV;
1894 if (!SvOK(sv))
1895 return FALSE;
1896 if (SvNOKp(sv))
1897 return Perl_isinfnan(SvNVX(sv));
1898 if (SvIOKp(sv))
1899 return FALSE;
1900 {
1901 STRLEN len;
1902 const char *s = SvPV_nomg_const(sv, len);
1903 return cBOOL(grok_infnan(&s, s+len));
1904 }
1905 }
1906
1907 #ifndef HAS_MODFL
1908 /* C99 has truncl, pre-C99 Solaris had aintl. We can use either with
1909 * copysignl to emulate modfl, which is in some platforms missing or
1910 * broken. */
1911 # if defined(HAS_TRUNCL) && defined(HAS_COPYSIGNL)
1912 long double
Perl_my_modfl(long double x,long double * ip)1913 Perl_my_modfl(long double x, long double *ip)
1914 {
1915 *ip = truncl(x);
1916 return (x == *ip ? copysignl(0.0L, x) : x - *ip);
1917 }
1918 # elif defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
1919 long double
Perl_my_modfl(long double x,long double * ip)1920 Perl_my_modfl(long double x, long double *ip)
1921 {
1922 *ip = aintl(x);
1923 return (x == *ip ? copysignl(0.0L, x) : x - *ip);
1924 }
1925 # endif
1926 #endif
1927
1928 /* Similarly, with ilogbl and scalbnl we can emulate frexpl. */
1929 #if ! defined(HAS_FREXPL) && defined(HAS_ILOGBL) && defined(HAS_SCALBNL)
1930 long double
Perl_my_frexpl(long double x,int * e)1931 Perl_my_frexpl(long double x, int *e) {
1932 *e = x == 0.0L ? 0 : ilogbl(x) + 1;
1933 return (scalbnl(x, -*e));
1934 }
1935 #endif
1936
1937 /*
1938 =for apidoc Perl_signbit
1939
1940 Return a non-zero integer if the sign bit on an NV is set, and 0 if
1941 it is not.
1942
1943 If F<Configure> detects this system has a C<signbit()> that will work with
1944 our NVs, then we just use it via the C<#define> in F<perl.h>. Otherwise,
1945 fall back on this implementation. The main use of this function
1946 is catching C<-0.0>.
1947
1948 C<Configure> notes: This function is called C<'Perl_signbit'> instead of a
1949 plain C<'signbit'> because it is easy to imagine a system having a C<signbit()>
1950 function or macro that doesn't happen to work with our particular choice
1951 of NVs. We shouldn't just re-C<#define> C<signbit> as C<Perl_signbit> and expect
1952 the standard system headers to be happy. Also, this is a no-context
1953 function (no C<pTHX_>) because C<Perl_signbit()> is usually re-C<#defined> in
1954 F<perl.h> as a simple macro call to the system's C<signbit()>.
1955 Users should just always call C<Perl_signbit()>.
1956
1957 =cut
1958 */
1959 #if !defined(HAS_SIGNBIT)
1960 int
Perl_signbit(NV x)1961 Perl_signbit(NV x) {
1962 # ifdef Perl_fp_class_nzero
1963 return Perl_fp_class_nzero(x);
1964 /* Try finding the high byte, and assume it's highest bit
1965 * is the sign. This assumption is probably wrong somewhere. */
1966 # elif defined(USE_LONG_DOUBLE) && LONG_DOUBLEKIND == LONG_DOUBLE_IS_X86_80_BIT_LITTLE_ENDIAN
1967 return (((unsigned char *)&x)[9] & 0x80);
1968 # elif defined(NV_LITTLE_ENDIAN)
1969 /* Note that NVSIZE is sizeof(NV), which would make the below be
1970 * wrong if the end bytes are unused, which happens with the x86
1971 * 80-bit long doubles, which is why take care of that above. */
1972 return (((unsigned char *)&x)[NVSIZE - 1] & 0x80);
1973 # elif defined(NV_BIG_ENDIAN)
1974 return (((unsigned char *)&x)[0] & 0x80);
1975 # else
1976 /* This last resort fallback is wrong for the negative zero. */
1977 return (x < 0.0) ? 1 : 0;
1978 # endif
1979 }
1980 #endif
1981
1982 /*
1983 * ex: set ts=8 sts=4 sw=4 et:
1984 */
1985