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[perl5.git] / numeric.c
CommitLineData
98994639
HS
1/* numeric.c
2 *
663f364b 3 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
1129b882 4 * 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
98994639
HS
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/*
4ac71550
TC
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"]
98994639
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16 */
17
ccfc67b7
JH
18/*
19=head1 Numeric functions
166f8a29 20
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KW
21=cut
22
166f8a29
DM
23This file contains all the stuff needed by perl for manipulating numeric
24values, including such things as replacements for the OS's atof() function
25
ccfc67b7
JH
26*/
27
98994639
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28#include "EXTERN.h"
29#define PERL_IN_NUMERIC_C
30#include "perl.h"
31
32U32
ddeaf645 33Perl_cast_ulong(NV f)
98994639
HS
34{
35 if (f < 0.0)
36 return f < I32_MIN ? (U32) I32_MIN : (U32)(I32) f;
37 if (f < U32_MAX_P1) {
38#if CASTFLAGS & 2
39 if (f < U32_MAX_P1_HALF)
40 return (U32) f;
41 f -= U32_MAX_P1_HALF;
42 return ((U32) f) | (1 + U32_MAX >> 1);
43#else
44 return (U32) f;
45#endif
46 }
47 return f > 0 ? U32_MAX : 0 /* NaN */;
48}
49
50I32
ddeaf645 51Perl_cast_i32(NV f)
98994639
HS
52{
53 if (f < I32_MAX_P1)
54 return f < I32_MIN ? I32_MIN : (I32) f;
55 if (f < U32_MAX_P1) {
56#if CASTFLAGS & 2
57 if (f < U32_MAX_P1_HALF)
58 return (I32)(U32) f;
59 f -= U32_MAX_P1_HALF;
60 return (I32)(((U32) f) | (1 + U32_MAX >> 1));
61#else
62 return (I32)(U32) f;
63#endif
64 }
65 return f > 0 ? (I32)U32_MAX : 0 /* NaN */;
66}
67
68IV
ddeaf645 69Perl_cast_iv(NV f)
98994639
HS
70{
71 if (f < IV_MAX_P1)
72 return f < IV_MIN ? IV_MIN : (IV) f;
73 if (f < UV_MAX_P1) {
74#if CASTFLAGS & 2
75 /* For future flexibility allowing for sizeof(UV) >= sizeof(IV) */
76 if (f < UV_MAX_P1_HALF)
77 return (IV)(UV) f;
78 f -= UV_MAX_P1_HALF;
79 return (IV)(((UV) f) | (1 + UV_MAX >> 1));
80#else
81 return (IV)(UV) f;
82#endif
83 }
84 return f > 0 ? (IV)UV_MAX : 0 /* NaN */;
85}
86
87UV
ddeaf645 88Perl_cast_uv(NV f)
98994639
HS
89{
90 if (f < 0.0)
91 return f < IV_MIN ? (UV) IV_MIN : (UV)(IV) f;
92 if (f < UV_MAX_P1) {
93#if CASTFLAGS & 2
94 if (f < UV_MAX_P1_HALF)
95 return (UV) f;
96 f -= UV_MAX_P1_HALF;
97 return ((UV) f) | (1 + UV_MAX >> 1);
98#else
99 return (UV) f;
100#endif
101 }
102 return f > 0 ? UV_MAX : 0 /* NaN */;
103}
104
53305cf1
NC
105/*
106=for apidoc grok_bin
98994639 107
53305cf1
NC
108converts a string representing a binary number to numeric form.
109
110On entry I<start> and I<*len> give the string to scan, I<*flags> gives
111conversion flags, and I<result> should be NULL or a pointer to an NV.
112The scan stops at the end of the string, or the first invalid character.
7b667b5f
MHM
113Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
114invalid character will also trigger a warning.
115On return I<*len> is set to the length of the scanned string,
116and I<*flags> gives output flags.
53305cf1 117
7fc63493 118If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
72d33970 119and nothing is written to I<*result>. If the value is > UV_MAX C<grok_bin>
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NC
120returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
121and writes the value to I<*result> (or the value is discarded if I<result>
122is NULL).
123
7b667b5f 124The binary number may optionally be prefixed with "0b" or "b" unless
72d33970 125C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If
a4c04bdc 126C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the binary
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127number may use '_' characters to separate digits.
128
129=cut
02470786
KW
130
131Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE
132which suppresses any message for non-portable numbers that are still valid
133on this platform.
53305cf1
NC
134 */
135
136UV
7918f24d
NC
137Perl_grok_bin(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
138{
53305cf1
NC
139 const char *s = start;
140 STRLEN len = *len_p;
141 UV value = 0;
142 NV value_nv = 0;
143
144 const UV max_div_2 = UV_MAX / 2;
f2338a2e 145 const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
53305cf1 146 bool overflowed = FALSE;
7fc63493 147 char bit;
53305cf1 148
7918f24d
NC
149 PERL_ARGS_ASSERT_GROK_BIN;
150
a4c04bdc
NC
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
154 numbers. */
155 if (len >= 1) {
a674e8db 156 if (s[0] == 'b' || s[0] == 'B') {
a4c04bdc
NC
157 s++;
158 len--;
159 }
a674e8db 160 else if (len >= 2 && s[0] == '0' && (s[1] == 'b' || s[1] == 'B')) {
a4c04bdc
NC
161 s+=2;
162 len-=2;
163 }
164 }
53305cf1
NC
165 }
166
7fc63493 167 for (; len-- && (bit = *s); s++) {
53305cf1
NC
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. */
172 redo:
173 if (!overflowed) {
174 if (value <= max_div_2) {
175 value = (value << 1) | (bit - '0');
176 continue;
177 }
178 /* Bah. We're just overflowed. */
dcbac5bb 179 /* diag_listed_as: Integer overflow in %s number */
9b387841
NC
180 Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW),
181 "Integer overflow in binary number");
53305cf1
NC
182 overflowed = TRUE;
183 value_nv = (NV) value;
184 }
185 value_nv *= 2.0;
98994639 186 /* If an NV has not enough bits in its mantissa to
d1be9408 187 * represent a UV this summing of small low-order numbers
98994639
HS
188 * is a waste of time (because the NV cannot preserve
189 * the low-order bits anyway): we could just remember when
53305cf1 190 * did we overflow and in the end just multiply value_nv by the
98994639 191 * right amount. */
53305cf1
NC
192 value_nv += (NV)(bit - '0');
193 continue;
194 }
195 if (bit == '_' && len && allow_underscores && (bit = s[1])
196 && (bit == '0' || bit == '1'))
98994639
HS
197 {
198 --len;
199 ++s;
53305cf1 200 goto redo;
98994639 201 }
a2a5de95
NC
202 if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT))
203 Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT),
204 "Illegal binary digit '%c' ignored", *s);
53305cf1 205 break;
98994639 206 }
53305cf1
NC
207
208 if ( ( overflowed && value_nv > 4294967295.0)
98994639 209#if UVSIZE > 4
02470786
KW
210 || (!overflowed && value > 0xffffffff
211 && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE))
98994639
HS
212#endif
213 ) {
a2a5de95
NC
214 Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE),
215 "Binary number > 0b11111111111111111111111111111111 non-portable");
53305cf1
NC
216 }
217 *len_p = s - start;
218 if (!overflowed) {
219 *flags = 0;
220 return value;
98994639 221 }
53305cf1
NC
222 *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
223 if (result)
224 *result = value_nv;
225 return UV_MAX;
98994639
HS
226}
227
53305cf1
NC
228/*
229=for apidoc grok_hex
230
231converts a string representing a hex number to numeric form.
232
c2da02fc 233On entry I<start> and I<*len_p> give the string to scan, I<*flags> gives
53305cf1 234conversion flags, and I<result> should be NULL or a pointer to an NV.
7b667b5f
MHM
235The scan stops at the end of the string, or the first invalid character.
236Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
237invalid character will also trigger a warning.
238On return I<*len> is set to the length of the scanned string,
239and I<*flags> gives output flags.
53305cf1
NC
240
241If the value is <= UV_MAX it is returned as a UV, the output flags are clear,
72d33970 242and nothing is written to I<*result>. If the value is > UV_MAX C<grok_hex>
53305cf1
NC
243returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
244and writes the value to I<*result> (or the value is discarded if I<result>
245is NULL).
246
d1be9408 247The hex number may optionally be prefixed with "0x" or "x" unless
72d33970 248C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If
a4c04bdc 249C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the hex
53305cf1
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250number may use '_' characters to separate digits.
251
252=cut
02470786
KW
253
254Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE
255which suppresses any message for non-portable numbers that are still valid
256on this platform.
53305cf1
NC
257 */
258
259UV
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260Perl_grok_hex(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
261{
53305cf1
NC
262 const char *s = start;
263 STRLEN len = *len_p;
264 UV value = 0;
265 NV value_nv = 0;
53305cf1 266 const UV max_div_16 = UV_MAX / 16;
f2338a2e 267 const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
53305cf1 268 bool overflowed = FALSE;
98994639 269
7918f24d
NC
270 PERL_ARGS_ASSERT_GROK_HEX;
271
a4c04bdc
NC
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.
275 */
276 if (len >= 1) {
a674e8db 277 if (s[0] == 'x' || s[0] == 'X') {
a4c04bdc
NC
278 s++;
279 len--;
280 }
a674e8db 281 else if (len >= 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) {
a4c04bdc
NC
282 s+=2;
283 len-=2;
284 }
285 }
98994639
HS
286 }
287
288 for (; len-- && *s; s++) {
626ef089 289 if (isXDIGIT(*s)) {
53305cf1
NC
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. */
293 redo:
294 if (!overflowed) {
295 if (value <= max_div_16) {
626ef089 296 value = (value << 4) | XDIGIT_VALUE(*s);
53305cf1
NC
297 continue;
298 }
299 /* Bah. We're just overflowed. */
dcbac5bb 300 /* diag_listed_as: Integer overflow in %s number */
9b387841
NC
301 Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW),
302 "Integer overflow in hexadecimal number");
53305cf1
NC
303 overflowed = TRUE;
304 value_nv = (NV) value;
305 }
306 value_nv *= 16.0;
307 /* If an NV has not enough bits in its mantissa to
d1be9408 308 * represent a UV this summing of small low-order numbers
53305cf1
NC
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. */
626ef089 313 value_nv += (NV) XDIGIT_VALUE(*s);
53305cf1
NC
314 continue;
315 }
316 if (*s == '_' && len && allow_underscores && s[1]
626ef089 317 && isXDIGIT(s[1]))
98994639
HS
318 {
319 --len;
320 ++s;
53305cf1 321 goto redo;
98994639 322 }
a2a5de95
NC
323 if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT))
324 Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT),
53305cf1
NC
325 "Illegal hexadecimal digit '%c' ignored", *s);
326 break;
327 }
328
329 if ( ( overflowed && value_nv > 4294967295.0)
330#if UVSIZE > 4
02470786
KW
331 || (!overflowed && value > 0xffffffff
332 && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE))
53305cf1
NC
333#endif
334 ) {
a2a5de95
NC
335 Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE),
336 "Hexadecimal number > 0xffffffff non-portable");
53305cf1
NC
337 }
338 *len_p = s - start;
339 if (!overflowed) {
340 *flags = 0;
341 return value;
342 }
343 *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
344 if (result)
345 *result = value_nv;
346 return UV_MAX;
347}
348
349/*
350=for apidoc grok_oct
351
7b667b5f
MHM
352converts a string representing an octal number to numeric form.
353
354On entry I<start> and I<*len> give the string to scan, I<*flags> gives
355conversion flags, and I<result> should be NULL or a pointer to an NV.
356The scan stops at the end of the string, or the first invalid character.
357Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
154bd527 3588 or 9 will also trigger a warning.
7b667b5f
MHM
359On return I<*len> is set to the length of the scanned string,
360and I<*flags> gives output flags.
361
362If the value is <= UV_MAX it is returned as a UV, the output flags are clear,
72d33970 363and nothing is written to I<*result>. If the value is > UV_MAX C<grok_oct>
7b667b5f
MHM
364returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
365and writes the value to I<*result> (or the value is discarded if I<result>
366is NULL).
367
368If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the octal
369number may use '_' characters to separate digits.
53305cf1
NC
370
371=cut
02470786 372
333ae27c
KW
373Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE>
374which suppresses any message for non-portable numbers, but which are valid
02470786 375on this platform.
53305cf1
NC
376 */
377
378UV
7918f24d
NC
379Perl_grok_oct(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result)
380{
53305cf1
NC
381 const char *s = start;
382 STRLEN len = *len_p;
383 UV value = 0;
384 NV value_nv = 0;
53305cf1 385 const UV max_div_8 = UV_MAX / 8;
f2338a2e 386 const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
53305cf1
NC
387 bool overflowed = FALSE;
388
7918f24d
NC
389 PERL_ARGS_ASSERT_GROK_OCT;
390
53305cf1 391 for (; len-- && *s; s++) {
626ef089 392 if (isOCTAL(*s)) {
53305cf1
NC
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.
395 */
396 redo:
397 if (!overflowed) {
398 if (value <= max_div_8) {
626ef089 399 value = (value << 3) | OCTAL_VALUE(*s);
53305cf1
NC
400 continue;
401 }
402 /* Bah. We're just overflowed. */
dcbac5bb 403 /* diag_listed_as: Integer overflow in %s number */
9b387841
NC
404 Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW),
405 "Integer overflow in octal number");
53305cf1
NC
406 overflowed = TRUE;
407 value_nv = (NV) value;
408 }
409 value_nv *= 8.0;
98994639 410 /* If an NV has not enough bits in its mantissa to
d1be9408 411 * represent a UV this summing of small low-order numbers
98994639
HS
412 * is a waste of time (because the NV cannot preserve
413 * the low-order bits anyway): we could just remember when
53305cf1
NC
414 * did we overflow and in the end just multiply value_nv by the
415 * right amount of 8-tuples. */
626ef089 416 value_nv += (NV) OCTAL_VALUE(*s);
53305cf1
NC
417 continue;
418 }
626ef089
KW
419 if (*s == '_' && len && allow_underscores && isOCTAL(s[1])) {
420 --len;
421 ++s;
422 goto redo;
423 }
53305cf1 424 /* Allow \octal to work the DWIM way (that is, stop scanning
7b667b5f 425 * as soon as non-octal characters are seen, complain only if
626ef089
KW
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). */
428 if (isDIGIT(*s)) {
a2a5de95
NC
429 if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT))
430 Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT),
431 "Illegal octal digit '%c' ignored", *s);
53305cf1
NC
432 }
433 break;
98994639 434 }
53305cf1
NC
435
436 if ( ( overflowed && value_nv > 4294967295.0)
98994639 437#if UVSIZE > 4
02470786
KW
438 || (!overflowed && value > 0xffffffff
439 && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE))
98994639
HS
440#endif
441 ) {
a2a5de95
NC
442 Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE),
443 "Octal number > 037777777777 non-portable");
53305cf1
NC
444 }
445 *len_p = s - start;
446 if (!overflowed) {
447 *flags = 0;
448 return value;
98994639 449 }
53305cf1
NC
450 *flags = PERL_SCAN_GREATER_THAN_UV_MAX;
451 if (result)
452 *result = value_nv;
453 return UV_MAX;
454}
455
456/*
457=for apidoc scan_bin
458
72d33970 459For backwards compatibility. Use C<grok_bin> instead.
53305cf1
NC
460
461=for apidoc scan_hex
462
72d33970 463For backwards compatibility. Use C<grok_hex> instead.
53305cf1
NC
464
465=for apidoc scan_oct
466
72d33970 467For backwards compatibility. Use C<grok_oct> instead.
53305cf1
NC
468
469=cut
470 */
471
472NV
73d840c0 473Perl_scan_bin(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
53305cf1
NC
474{
475 NV rnv;
476 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
73d840c0 477 const UV ruv = grok_bin (start, &len, &flags, &rnv);
53305cf1 478
7918f24d
NC
479 PERL_ARGS_ASSERT_SCAN_BIN;
480
53305cf1
NC
481 *retlen = len;
482 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
483}
484
485NV
73d840c0 486Perl_scan_oct(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
53305cf1
NC
487{
488 NV rnv;
489 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
73d840c0 490 const UV ruv = grok_oct (start, &len, &flags, &rnv);
53305cf1 491
7918f24d
NC
492 PERL_ARGS_ASSERT_SCAN_OCT;
493
53305cf1
NC
494 *retlen = len;
495 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
496}
497
498NV
73d840c0 499Perl_scan_hex(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
53305cf1
NC
500{
501 NV rnv;
502 I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
73d840c0 503 const UV ruv = grok_hex (start, &len, &flags, &rnv);
53305cf1 504
7918f24d
NC
505 PERL_ARGS_ASSERT_SCAN_HEX;
506
53305cf1
NC
507 *retlen = len;
508 return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
98994639
HS
509}
510
511/*
512=for apidoc grok_numeric_radix
513
514Scan and skip for a numeric decimal separator (radix).
515
516=cut
517 */
518bool
519Perl_grok_numeric_radix(pTHX_ const char **sp, const char *send)
520{
521#ifdef USE_LOCALE_NUMERIC
7918f24d
NC
522 PERL_ARGS_ASSERT_GROK_NUMERIC_RADIX;
523
d6ded950 524 if (IN_LC(LC_NUMERIC)) {
21431899
KW
525 DECLARE_STORE_LC_NUMERIC_SET_TO_NEEDED();
526 if (PL_numeric_radix_sv) {
c5a7e38e
KW
527 STRLEN len;
528 const char * const radix = SvPV(PL_numeric_radix_sv, len);
529 if (*sp + len <= send && memEQ(*sp, radix, len)) {
530 *sp += len;
531 RESTORE_LC_NUMERIC();
532 return TRUE;
533 }
21431899
KW
534 }
535 RESTORE_LC_NUMERIC();
98994639
HS
536 }
537 /* always try "." if numeric radix didn't match because
538 * we may have data from different locales mixed */
539#endif
7918f24d
NC
540
541 PERL_ARGS_ASSERT_GROK_NUMERIC_RADIX;
542
98994639
HS
543 if (*sp < send && **sp == '.') {
544 ++*sp;
545 return TRUE;
546 }
547 return FALSE;
548}
549
550/*
3f7602fa 551=for apidoc grok_number_flags
98994639
HS
552
553Recognise (or not) a number. The type of the number is returned
554(0 if unrecognised), otherwise it is a bit-ORed combination of
555IS_NUMBER_IN_UV, IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT,
aa8b85de 556IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h).
60939fb8 557
cd164854 558If the value of the number can fit in a UV, it is returned in the *valuep
60939fb8
NC
559IS_NUMBER_IN_UV will be set to indicate that *valuep is valid, IS_NUMBER_IN_UV
560will never be set unless *valuep is valid, but *valuep may have been assigned
561to during processing even though IS_NUMBER_IN_UV is not set on return.
562If valuep is NULL, IS_NUMBER_IN_UV will be set for the same cases as when
563valuep is non-NULL, but no actual assignment (or SEGV) will occur.
564
565IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing decimals were
566seen (in which case *valuep gives the true value truncated to an integer), and
567IS_NUMBER_NEG if the number is negative (in which case *valuep holds the
568absolute value). IS_NUMBER_IN_UV is not set if e notation was used or the
569number is larger than a UV.
98994639 570
3f7602fa
TC
571C<flags> allows only C<PERL_SCAN_TRAILING>, which allows for trailing
572non-numeric text on an otherwise successful I<grok>, setting
573C<IS_NUMBER_TRAILING> on the result.
574
575=for apidoc grok_number
576
577Identical to grok_number_flags() with flags set to zero.
578
98994639
HS
579=cut
580 */
581int
582Perl_grok_number(pTHX_ const char *pv, STRLEN len, UV *valuep)
583{
3f7602fa
TC
584 PERL_ARGS_ASSERT_GROK_NUMBER;
585
586 return grok_number_flags(pv, len, valuep, 0);
587}
588
945b524a
JH
589static const UV uv_max_div_10 = UV_MAX / 10;
590static const U8 uv_max_mod_10 = UV_MAX % 10;
591
3f7602fa
TC
592int
593Perl_grok_number_flags(pTHX_ const char *pv, STRLEN len, UV *valuep, U32 flags)
594{
60939fb8 595 const char *s = pv;
c4420975 596 const char * const send = pv + len;
60939fb8
NC
597 int numtype = 0;
598 int sawinf = 0;
aa8b85de 599 int sawnan = 0;
60939fb8 600
3f7602fa 601 PERL_ARGS_ASSERT_GROK_NUMBER_FLAGS;
7918f24d 602
60939fb8
NC
603 while (s < send && isSPACE(*s))
604 s++;
605 if (s == send) {
606 return 0;
607 } else if (*s == '-') {
608 s++;
609 numtype = IS_NUMBER_NEG;
610 }
611 else if (*s == '+')
aa42a541 612 s++;
60939fb8
NC
613
614 if (s == send)
615 return 0;
616
617 /* next must be digit or the radix separator or beginning of infinity */
618 if (isDIGIT(*s)) {
619 /* UVs are at least 32 bits, so the first 9 decimal digits cannot
620 overflow. */
621 UV value = *s - '0';
622 /* This construction seems to be more optimiser friendly.
623 (without it gcc does the isDIGIT test and the *s - '0' separately)
624 With it gcc on arm is managing 6 instructions (6 cycles) per digit.
625 In theory the optimiser could deduce how far to unroll the loop
626 before checking for overflow. */
58bb9ec3
NC
627 if (++s < send) {
628 int digit = *s - '0';
60939fb8
NC
629 if (digit >= 0 && digit <= 9) {
630 value = value * 10 + digit;
58bb9ec3
NC
631 if (++s < send) {
632 digit = *s - '0';
60939fb8
NC
633 if (digit >= 0 && digit <= 9) {
634 value = value * 10 + digit;
58bb9ec3
NC
635 if (++s < send) {
636 digit = *s - '0';
60939fb8
NC
637 if (digit >= 0 && digit <= 9) {
638 value = value * 10 + digit;
58bb9ec3
NC
639 if (++s < send) {
640 digit = *s - '0';
60939fb8
NC
641 if (digit >= 0 && digit <= 9) {
642 value = value * 10 + digit;
58bb9ec3
NC
643 if (++s < send) {
644 digit = *s - '0';
60939fb8
NC
645 if (digit >= 0 && digit <= 9) {
646 value = value * 10 + digit;
58bb9ec3
NC
647 if (++s < send) {
648 digit = *s - '0';
60939fb8
NC
649 if (digit >= 0 && digit <= 9) {
650 value = value * 10 + digit;
58bb9ec3
NC
651 if (++s < send) {
652 digit = *s - '0';
60939fb8
NC
653 if (digit >= 0 && digit <= 9) {
654 value = value * 10 + digit;
58bb9ec3
NC
655 if (++s < send) {
656 digit = *s - '0';
60939fb8
NC
657 if (digit >= 0 && digit <= 9) {
658 value = value * 10 + digit;
58bb9ec3 659 if (++s < send) {
60939fb8
NC
660 /* Now got 9 digits, so need to check
661 each time for overflow. */
58bb9ec3 662 digit = *s - '0';
60939fb8 663 while (digit >= 0 && digit <= 9
945b524a
JH
664 && (value < uv_max_div_10
665 || (value == uv_max_div_10
666 && digit <= uv_max_mod_10))) {
60939fb8 667 value = value * 10 + digit;
58bb9ec3
NC
668 if (++s < send)
669 digit = *s - '0';
60939fb8
NC
670 else
671 break;
672 }
673 if (digit >= 0 && digit <= 9
51bd16da 674 && (s < send)) {
60939fb8
NC
675 /* value overflowed.
676 skip the remaining digits, don't
677 worry about setting *valuep. */
678 do {
679 s++;
680 } while (s < send && isDIGIT(*s));
681 numtype |=
682 IS_NUMBER_GREATER_THAN_UV_MAX;
683 goto skip_value;
684 }
685 }
686 }
98994639 687 }
60939fb8
NC
688 }
689 }
690 }
691 }
692 }
693 }
694 }
695 }
696 }
697 }
698 }
98994639 699 }
60939fb8 700 }
98994639 701 }
60939fb8
NC
702 numtype |= IS_NUMBER_IN_UV;
703 if (valuep)
704 *valuep = value;
705
706 skip_value:
707 if (GROK_NUMERIC_RADIX(&s, send)) {
708 numtype |= IS_NUMBER_NOT_INT;
709 while (s < send && isDIGIT(*s)) /* optional digits after the radix */
710 s++;
98994639 711 }
60939fb8
NC
712 }
713 else if (GROK_NUMERIC_RADIX(&s, send)) {
714 numtype |= IS_NUMBER_NOT_INT | IS_NUMBER_IN_UV; /* valuep assigned below */
715 /* no digits before the radix means we need digits after it */
716 if (s < send && isDIGIT(*s)) {
717 do {
718 s++;
719 } while (s < send && isDIGIT(*s));
720 if (valuep) {
721 /* integer approximation is valid - it's 0. */
722 *valuep = 0;
723 }
98994639 724 }
60939fb8
NC
725 else
726 return 0;
727 } else if (*s == 'I' || *s == 'i') {
728 s++; if (s == send || (*s != 'N' && *s != 'n')) return 0;
729 s++; if (s == send || (*s != 'F' && *s != 'f')) return 0;
730 s++; if (s < send && (*s == 'I' || *s == 'i')) {
731 s++; if (s == send || (*s != 'N' && *s != 'n')) return 0;
732 s++; if (s == send || (*s != 'I' && *s != 'i')) return 0;
733 s++; if (s == send || (*s != 'T' && *s != 't')) return 0;
734 s++; if (s == send || (*s != 'Y' && *s != 'y')) return 0;
735 s++;
98994639 736 }
60939fb8 737 sawinf = 1;
aa8b85de
JH
738 } else if (*s == 'N' || *s == 'n') {
739 /* XXX TODO: There are signaling NaNs and quiet NaNs. */
740 s++; if (s == send || (*s != 'A' && *s != 'a')) return 0;
741 s++; if (s == send || (*s != 'N' && *s != 'n')) return 0;
742 s++;
743 sawnan = 1;
744 } else
98994639 745 return 0;
60939fb8
NC
746
747 if (sawinf) {
748 numtype &= IS_NUMBER_NEG; /* Keep track of sign */
749 numtype |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT;
aa8b85de
JH
750 } else if (sawnan) {
751 numtype &= IS_NUMBER_NEG; /* Keep track of sign */
752 numtype |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
60939fb8
NC
753 } else if (s < send) {
754 /* we can have an optional exponent part */
755 if (*s == 'e' || *s == 'E') {
60939fb8
NC
756 s++;
757 if (s < send && (*s == '-' || *s == '+'))
758 s++;
759 if (s < send && isDIGIT(*s)) {
760 do {
761 s++;
762 } while (s < send && isDIGIT(*s));
763 }
3f7602fa
TC
764 else if (flags & PERL_SCAN_TRAILING)
765 return numtype | IS_NUMBER_TRAILING;
60939fb8 766 else
3f7602fa
TC
767 return 0;
768
769 /* The only flag we keep is sign. Blow away any "it's UV" */
770 numtype &= IS_NUMBER_NEG;
771 numtype |= IS_NUMBER_NOT_INT;
60939fb8
NC
772 }
773 }
774 while (s < send && isSPACE(*s))
775 s++;
776 if (s >= send)
aa8b85de 777 return numtype;
60939fb8
NC
778 if (len == 10 && memEQ(pv, "0 but true", 10)) {
779 if (valuep)
780 *valuep = 0;
781 return IS_NUMBER_IN_UV;
782 }
3f7602fa
TC
783 else if (flags & PERL_SCAN_TRAILING) {
784 return numtype | IS_NUMBER_TRAILING;
785 }
786
60939fb8 787 return 0;
98994639
HS
788}
789
6313e544 790/*
d62b8c6a 791=for apidoc grok_atou
6313e544 792
d62b8c6a 793grok_atou is a safer replacement for atoi and strtol.
6313e544 794
d62b8c6a
JH
795grok_atou parses a C-style zero-byte terminated string, looking for
796a decimal unsigned integer.
338aa8b0 797
d62b8c6a
JH
798Returns the unsigned integer, if a valid value can be parsed
799from the beginning of the string.
f4379102 800
d62b8c6a 801Accepts only the decimal digits '0'..'9'.
6313e544 802
d62b8c6a
JH
803As opposed to atoi or strtol, grok_atou does NOT allow optional
804leading whitespace, or negative inputs. If such features are
805required, the calling code needs to explicitly implement those.
6313e544 806
d62b8c6a 807If a valid value cannot be parsed, returns either zero (if non-digits
75feedba 808are met before any digits) or UV_MAX (if the value overflows).
6313e544 809
d62b8c6a
JH
810Note that extraneous leading zeros also count as an overflow
811(meaning that only "0" is the zero).
338aa8b0 812
d62b8c6a 813On failure, the *endptr is also set to NULL, unless endptr is NULL.
338aa8b0
JH
814
815Trailing non-digit bytes are allowed if the endptr is non-NULL.
6313e544
JH
816On return the *endptr will contain the pointer to the first non-digit byte.
817
6313e544 818If the endptr is NULL, the first non-digit byte MUST be
f4379102 819the zero byte terminating the pv, or zero will be returned.
6313e544 820
d62b8c6a
JH
821Background: atoi has severe problems with illegal inputs, it cannot be
822used for incremental parsing, and therefore should be avoided
823atoi and strtol are also affected by locale settings, which can also be
824seen as a bug (global state controlled by user environment).
825
6313e544
JH
826=cut
827*/
828
75feedba 829UV
6313e544
JH
830Perl_grok_atou(const char *pv, const char** endptr)
831{
832 const char* s = pv;
833 const char** eptr;
834 const char* end2; /* Used in case endptr is NULL. */
75feedba 835 UV val = 0; /* The return value. */
6313e544
JH
836
837 PERL_ARGS_ASSERT_GROK_ATOU;
838
839 eptr = endptr ? endptr : &end2;
75feedba
JH
840 if (isDIGIT(*s)) {
841 /* Single-digit inputs are quite common. */
6313e544 842 val = *s++ - '0';
75feedba
JH
843 if (isDIGIT(*s)) {
844 /* Extra leading zeros cause overflow. */
845 if (val == 0) {
846 *eptr = NULL;
847 return UV_MAX;
848 }
849 while (isDIGIT(*s)) {
850 /* This could be unrolled like in grok_number(), but
851 * the expected uses of this are not speed-needy, and
852 * unlikely to need full 64-bitness. */
853 U8 digit = *s++ - '0';
945b524a
JH
854 if (val < uv_max_div_10 ||
855 (val == uv_max_div_10 && digit <= uv_max_mod_10)) {
75feedba
JH
856 val = val * 10 + digit;
857 } else {
6313e544 858 *eptr = NULL;
75feedba 859 return UV_MAX;
6313e544 860 }
6313e544
JH
861 }
862 }
75feedba
JH
863 }
864 if (s == pv) {
865 *eptr = NULL; /* If no progress, failed to parse anything. */
866 return 0;
6313e544
JH
867 }
868 if (endptr == NULL && *s) {
869 return 0; /* If endptr is NULL, no trailing non-digits allowed. */
870 }
871 *eptr = s;
872 return val;
873}
874
4801ca72 875STATIC NV
98994639
HS
876S_mulexp10(NV value, I32 exponent)
877{
878 NV result = 1.0;
879 NV power = 10.0;
880 bool negative = 0;
881 I32 bit;
882
883 if (exponent == 0)
884 return value;
659c4b96
DM
885 if (value == 0)
886 return (NV)0;
87032ba1 887
24866caa 888 /* On OpenVMS VAX we by default use the D_FLOAT double format,
67597c89 889 * and that format does not have *easy* capabilities [1] for
24866caa
CB
890 * overflowing doubles 'silently' as IEEE fp does. We also need
891 * to support G_FLOAT on both VAX and Alpha, and though the exponent
892 * range is much larger than D_FLOAT it still doesn't do silent
893 * overflow. Therefore we need to detect early whether we would
894 * overflow (this is the behaviour of the native string-to-float
895 * conversion routines, and therefore of native applications, too).
67597c89 896 *
24866caa
CB
897 * [1] Trying to establish a condition handler to trap floating point
898 * exceptions is not a good idea. */
87032ba1
JH
899
900 /* In UNICOS and in certain Cray models (such as T90) there is no
901 * IEEE fp, and no way at all from C to catch fp overflows gracefully.
902 * There is something you can do if you are willing to use some
903 * inline assembler: the instruction is called DFI-- but that will
904 * disable *all* floating point interrupts, a little bit too large
905 * a hammer. Therefore we need to catch potential overflows before
906 * it's too late. */
353813d9 907
85bba25f 908#if ((defined(VMS) && !defined(_IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP)
353813d9 909 STMT_START {
c4420975 910 const NV exp_v = log10(value);
353813d9
HS
911 if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP)
912 return NV_MAX;
913 if (exponent < 0) {
914 if (-(exponent + exp_v) >= NV_MAX_10_EXP)
915 return 0.0;
916 while (-exponent >= NV_MAX_10_EXP) {
917 /* combination does not overflow, but 10^(-exponent) does */
918 value /= 10;
919 ++exponent;
920 }
921 }
922 } STMT_END;
87032ba1
JH
923#endif
924
353813d9
HS
925 if (exponent < 0) {
926 negative = 1;
927 exponent = -exponent;
b27804d8
DM
928#ifdef NV_MAX_10_EXP
929 /* for something like 1234 x 10^-309, the action of calculating
930 * the intermediate value 10^309 then returning 1234 / (10^309)
931 * will fail, since 10^309 becomes infinity. In this case try to
932 * refactor it as 123 / (10^308) etc.
933 */
934 while (value && exponent > NV_MAX_10_EXP) {
935 exponent--;
936 value /= 10;
937 }
938#endif
353813d9 939 }
98994639
HS
940 for (bit = 1; exponent; bit <<= 1) {
941 if (exponent & bit) {
942 exponent ^= bit;
943 result *= power;
236f0012
CB
944 /* Floating point exceptions are supposed to be turned off,
945 * but if we're obviously done, don't risk another iteration.
946 */
947 if (exponent == 0) break;
98994639
HS
948 }
949 power *= power;
950 }
951 return negative ? value / result : value * result;
952}
953
954NV
955Perl_my_atof(pTHX_ const char* s)
956{
957 NV x = 0.0;
958#ifdef USE_LOCALE_NUMERIC
7918f24d
NC
959 PERL_ARGS_ASSERT_MY_ATOF;
960
a2287a13
KW
961 {
962 DECLARE_STORE_LC_NUMERIC_SET_TO_NEEDED();
d6ded950 963 if (PL_numeric_radix_sv && IN_LC(LC_NUMERIC)) {
e4850248
KW
964 const char *standard = NULL, *local = NULL;
965 bool use_standard_radix;
98994639 966
e4850248
KW
967 /* Look through the string for the first thing that looks like a
968 * decimal point: either the value in the current locale or the
969 * standard fallback of '.'. The one which appears earliest in the
970 * input string is the one that we should have atof look for. Note
971 * that we have to determine this beforehand because on some
972 * systems, Perl_atof2 is just a wrapper around the system's atof.
973 * */
974 standard = strchr(s, '.');
975 local = strstr(s, SvPV_nolen(PL_numeric_radix_sv));
78787052 976
e4850248 977 use_standard_radix = standard && (!local || standard < local);
78787052 978
e4850248
KW
979 if (use_standard_radix)
980 SET_NUMERIC_STANDARD();
78787052 981
e4850248 982 Perl_atof2(s, x);
78787052 983
e4850248
KW
984 if (use_standard_radix)
985 SET_NUMERIC_LOCAL();
986 }
987 else
988 Perl_atof2(s, x);
a2287a13
KW
989 RESTORE_LC_NUMERIC();
990 }
98994639 991#else
a36244b7 992 Perl_atof2(s, x);
98994639
HS
993#endif
994 return x;
995}
996
997char*
998Perl_my_atof2(pTHX_ const char* orig, NV* value)
999{
20f6aaab 1000 NV result[3] = {0.0, 0.0, 0.0};
e1ec3a88 1001 const char* s = orig;
a36244b7 1002#ifdef USE_PERL_ATOF
20f6aaab 1003 UV accumulator[2] = {0,0}; /* before/after dp */
a36244b7 1004 bool negative = 0;
e1ec3a88 1005 const char* send = s + strlen(orig) - 1;
8194bf88 1006 bool seen_digit = 0;
20f6aaab
AS
1007 I32 exp_adjust[2] = {0,0};
1008 I32 exp_acc[2] = {-1, -1};
1009 /* the current exponent adjust for the accumulators */
98994639 1010 I32 exponent = 0;
8194bf88 1011 I32 seen_dp = 0;
20f6aaab
AS
1012 I32 digit = 0;
1013 I32 old_digit = 0;
8194bf88
DM
1014 I32 sig_digits = 0; /* noof significant digits seen so far */
1015
7918f24d
NC
1016 PERL_ARGS_ASSERT_MY_ATOF2;
1017
8194bf88
DM
1018/* There is no point in processing more significant digits
1019 * than the NV can hold. Note that NV_DIG is a lower-bound value,
1020 * while we need an upper-bound value. We add 2 to account for this;
1021 * since it will have been conservative on both the first and last digit.
1022 * For example a 32-bit mantissa with an exponent of 4 would have
1023 * exact values in the set
1024 * 4
1025 * 8
1026 * ..
1027 * 17179869172
1028 * 17179869176
1029 * 17179869180
1030 *
1031 * where for the purposes of calculating NV_DIG we would have to discount
1032 * both the first and last digit, since neither can hold all values from
1033 * 0..9; but for calculating the value we must examine those two digits.
1034 */
ffa277e5
EAS
1035#ifdef MAX_SIG_DIG_PLUS
1036 /* It is not necessarily the case that adding 2 to NV_DIG gets all the
1037 possible digits in a NV, especially if NVs are not IEEE compliant
1038 (e.g., long doubles on IRIX) - Allen <allens@cpan.org> */
1039# define MAX_SIG_DIGITS (NV_DIG+MAX_SIG_DIG_PLUS)
1040#else
1041# define MAX_SIG_DIGITS (NV_DIG+2)
1042#endif
8194bf88
DM
1043
1044/* the max number we can accumulate in a UV, and still safely do 10*N+9 */
1045#define MAX_ACCUMULATE ( (UV) ((UV_MAX - 9)/10))
98994639 1046
96a05aee
HS
1047 /* leading whitespace */
1048 while (isSPACE(*s))
1049 ++s;
1050
98994639
HS
1051 /* sign */
1052 switch (*s) {
1053 case '-':
1054 negative = 1;
924ba076 1055 /* FALLTHROUGH */
98994639
HS
1056 case '+':
1057 ++s;
1058 }
1059
2b54f59f
YST
1060 /* punt to strtod for NaN/Inf; if no support for it there, tough luck */
1061
1062#ifdef HAS_STRTOD
1063 if (*s == 'n' || *s == 'N' || *s == 'i' || *s == 'I') {
c042ae3a 1064 const char *p = negative ? s - 1 : s;
2b54f59f
YST
1065 char *endp;
1066 NV rslt;
1067 rslt = strtod(p, &endp);
1068 if (endp != p) {
1069 *value = rslt;
1070 return (char *)endp;
1071 }
1072 }
1073#endif
1074
8194bf88
DM
1075 /* we accumulate digits into an integer; when this becomes too
1076 * large, we add the total to NV and start again */
98994639 1077
8194bf88
DM
1078 while (1) {
1079 if (isDIGIT(*s)) {
1080 seen_digit = 1;
20f6aaab 1081 old_digit = digit;
8194bf88 1082 digit = *s++ - '0';
20f6aaab
AS
1083 if (seen_dp)
1084 exp_adjust[1]++;
98994639 1085
8194bf88
DM
1086 /* don't start counting until we see the first significant
1087 * digit, eg the 5 in 0.00005... */
1088 if (!sig_digits && digit == 0)
1089 continue;
1090
1091 if (++sig_digits > MAX_SIG_DIGITS) {
98994639 1092 /* limits of precision reached */
20f6aaab
AS
1093 if (digit > 5) {
1094 ++accumulator[seen_dp];
1095 } else if (digit == 5) {
1096 if (old_digit % 2) { /* round to even - Allen */
1097 ++accumulator[seen_dp];
1098 }
1099 }
1100 if (seen_dp) {
1101 exp_adjust[1]--;
1102 } else {
1103 exp_adjust[0]++;
1104 }
8194bf88 1105 /* skip remaining digits */
98994639 1106 while (isDIGIT(*s)) {
98994639 1107 ++s;
20f6aaab
AS
1108 if (! seen_dp) {
1109 exp_adjust[0]++;
1110 }
98994639
HS
1111 }
1112 /* warn of loss of precision? */
98994639 1113 }
8194bf88 1114 else {
20f6aaab 1115 if (accumulator[seen_dp] > MAX_ACCUMULATE) {
8194bf88 1116 /* add accumulator to result and start again */
20f6aaab
AS
1117 result[seen_dp] = S_mulexp10(result[seen_dp],
1118 exp_acc[seen_dp])
1119 + (NV)accumulator[seen_dp];
1120 accumulator[seen_dp] = 0;
1121 exp_acc[seen_dp] = 0;
98994639 1122 }
20f6aaab
AS
1123 accumulator[seen_dp] = accumulator[seen_dp] * 10 + digit;
1124 ++exp_acc[seen_dp];
98994639 1125 }
8194bf88 1126 }
e1ec3a88 1127 else if (!seen_dp && GROK_NUMERIC_RADIX(&s, send)) {
8194bf88 1128 seen_dp = 1;
20f6aaab 1129 if (sig_digits > MAX_SIG_DIGITS) {
c86f7df5 1130 do {
20f6aaab 1131 ++s;
c86f7df5 1132 } while (isDIGIT(*s));
20f6aaab
AS
1133 break;
1134 }
8194bf88
DM
1135 }
1136 else {
1137 break;
98994639
HS
1138 }
1139 }
1140
20f6aaab
AS
1141 result[0] = S_mulexp10(result[0], exp_acc[0]) + (NV)accumulator[0];
1142 if (seen_dp) {
1143 result[1] = S_mulexp10(result[1], exp_acc[1]) + (NV)accumulator[1];
1144 }
98994639 1145
8194bf88 1146 if (seen_digit && (*s == 'e' || *s == 'E')) {
98994639
HS
1147 bool expnegative = 0;
1148
1149 ++s;
1150 switch (*s) {
1151 case '-':
1152 expnegative = 1;
924ba076 1153 /* FALLTHROUGH */
98994639
HS
1154 case '+':
1155 ++s;
1156 }
1157 while (isDIGIT(*s))
1158 exponent = exponent * 10 + (*s++ - '0');
1159 if (expnegative)
1160 exponent = -exponent;
1161 }
1162
20f6aaab
AS
1163
1164
98994639 1165 /* now apply the exponent */
20f6aaab
AS
1166
1167 if (seen_dp) {
1168 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0])
1169 + S_mulexp10(result[1],exponent-exp_adjust[1]);
1170 } else {
1171 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]);
1172 }
98994639
HS
1173
1174 /* now apply the sign */
1175 if (negative)
20f6aaab 1176 result[2] = -result[2];
a36244b7 1177#endif /* USE_PERL_ATOF */
20f6aaab 1178 *value = result[2];
73d840c0 1179 return (char *)s;
98994639
HS
1180}
1181
55954f19
JH
1182#if ! defined(HAS_MODFL) && defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
1183long double
1184Perl_my_modfl(long double x, long double *ip)
1185{
1186 *ip = aintl(x);
1187 return (x == *ip ? copysignl(0.0L, x) : x - *ip);
1188}
1189#endif
1190
1191#if ! defined(HAS_FREXPL) && defined(HAS_ILOGBL) && defined(HAS_SCALBNL)
1192long double
1193Perl_my_frexpl(long double x, int *e) {
1194 *e = x == 0.0L ? 0 : ilogbl(x) + 1;
1195 return (scalbnl(x, -*e));
1196}
1197#endif
66610fdd
RGS
1198
1199/*
ed140128
AD
1200=for apidoc Perl_signbit
1201
1202Return a non-zero integer if the sign bit on an NV is set, and 0 if
1203it is not.
1204
1205If Configure detects this system has a signbit() that will work with
1206our NVs, then we just use it via the #define in perl.h. Otherwise,
8b7fad81
JH
1207fall back on this implementation. The main use of this function
1208is catching -0.0.
ed140128
AD
1209
1210Configure notes: This function is called 'Perl_signbit' instead of a
1211plain 'signbit' because it is easy to imagine a system having a signbit()
1212function or macro that doesn't happen to work with our particular choice
1213of NVs. We shouldn't just re-#define signbit as Perl_signbit and expect
1214the standard system headers to be happy. Also, this is a no-context
1215function (no pTHX_) because Perl_signbit() is usually re-#defined in
1216perl.h as a simple macro call to the system's signbit().
1217Users should just always call Perl_signbit().
1218
1219=cut
1220*/
1221#if !defined(HAS_SIGNBIT)
1222int
1223Perl_signbit(NV x) {
8b7fad81
JH
1224# ifdef Perl_fp_class_nzero
1225 if (x == 0)
1226 return Perl_fp_class_nzero(x);
1227# else
ed140128 1228 return (x < 0.0) ? 1 : 0;
8b7fad81 1229# endif
ed140128
AD
1230}
1231#endif
1232
1233/*
66610fdd
RGS
1234 * Local variables:
1235 * c-indentation-style: bsd
1236 * c-basic-offset: 4
14d04a33 1237 * indent-tabs-mode: nil
66610fdd
RGS
1238 * End:
1239 *
14d04a33 1240 * ex: set ts=8 sts=4 sw=4 et:
37442d52 1241 */