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POSIX math: log1p is more subtle.
[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
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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
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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) {
305b8651 156 if (isALPHA_FOLD_EQ(s[0], 'b')) {
a4c04bdc
NC
157 s++;
158 len--;
159 }
305b8651 160 else if (len >= 2 && s[0] == '0' && (isALPHA_FOLD_EQ(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
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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
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253
254Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE
baf48926 255which suppresses any message for non-portable numbers, but which are valid
02470786 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) {
305b8651 277 if (isALPHA_FOLD_EQ(s[0], 'x')) {
a4c04bdc
NC
278 s++;
279 len--;
280 }
305b8651 281 else if (len >= 2 && s[0] == '0' && (isALPHA_FOLD_EQ(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
ff4eb398
JH
589/*
590=for apidoc grok_infnan
591
592Helper for grok_number(), accepts various ways of spelling "infinity"
593or "not a number", and returns one of the following flag combinations:
594
595 IS_NUMBER_INFINITE
596 IS_NUMBER_NAN
597 IS_NUMBER_INFINITE | IS_NUMBER_NEG
598 IS_NUMBER_NAN | IS_NUMBER_NEG
599 0
600
601If an infinity or not-a-number is recognized, the *sp will point to
602one past the end of the recognized string. If the recognition fails,
603zero is returned, and the *sp will not move.
604
605=cut
606*/
607
608int
609Perl_grok_infnan(const char** sp, const char* send)
610{
611 const char* s = *sp;
612 int flags = 0;
613
614 PERL_ARGS_ASSERT_GROK_INFNAN;
615
8c12dc63
JH
616 if (*s == '+') {
617 s++; if (s == send) return 0;
618 }
619 else if (*s == '-') {
ff4eb398
JH
620 flags |= IS_NUMBER_NEG; /* Yes, -NaN happens. Incorrect but happens. */
621 s++; if (s == send) return 0;
622 }
623
624 if (*s == '1') {
625 /* Visual C: 1.#SNAN, -1.#QNAN, 1#INF, 1#.IND (maybe also 1.#NAN) */
626 s++; if (s == send) return 0;
627 if (*s == '.') {
628 s++; if (s == send) return 0;
629 }
630 if (*s == '#') {
631 s++; if (s == send) return 0;
632 } else
633 return 0;
634 }
635
305b8651 636 if (isALPHA_FOLD_EQ(*s, 'I')) {
ff4eb398 637 /* INF or IND (1.#IND is indeterminate, a certain type of NAN) */
305b8651 638 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return 0;
ff4eb398 639 s++; if (s == send) return 0;
305b8651 640 if (isALPHA_FOLD_EQ(*s, 'F')) {
ff4eb398 641 s++;
305b8651
KW
642 if (s < send && (isALPHA_FOLD_EQ(*s, 'I'))) {
643 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return 0;
644 s++; if (s == send || isALPHA_FOLD_NE(*s, 'I')) return 0;
645 s++; if (s == send || isALPHA_FOLD_NE(*s, 'T')) return 0;
8c12dc63
JH
646 s++; if (s == send ||
647 /* allow either Infinity or Infinite */
0ec38c0a
JH
648 !(isALPHA_FOLD_EQ(*s, 'Y') ||
649 isALPHA_FOLD_EQ(*s, 'E'))) return 0;
650 s++; if (s < send) return 0;
ff4eb398
JH
651 } else if (*s)
652 return 0;
653 flags |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT;
654 }
305b8651 655 else if (isALPHA_FOLD_EQ(*s, 'D')) {
ff4eb398
JH
656 s++;
657 flags |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
658 } else
659 return 0;
ff4eb398
JH
660 }
661 else {
662 /* NAN */
305b8651 663 if (isALPHA_FOLD_EQ(*s, 'S') || isALPHA_FOLD_EQ(*s, 'Q')) {
ff4eb398
JH
664 /* snan, qNaN */
665 /* XXX do something with the snan/qnan difference */
ae776a2c 666 s++; if (s == send) return 0;
ff4eb398
JH
667 }
668
305b8651
KW
669 if (isALPHA_FOLD_EQ(*s, 'N')) {
670 s++; if (s == send || isALPHA_FOLD_NE(*s, 'A')) return 0;
671 s++; if (s == send || isALPHA_FOLD_NE(*s, 'N')) return 0;
ff4eb398
JH
672 s++;
673
ae776a2c
JH
674 flags |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
675
8c12dc63
JH
676 /* NaN can be followed by various stuff (NaNQ, NaNS), but
677 * there are also multiple different NaN values, and some
678 * implementations output the "payload" values,
679 * e.g. NaN123, NAN(abc), while some implementations just
680 * have weird stuff like NaN%. */
ae776a2c 681 s = send;
ff4eb398 682 }
ae776a2c
JH
683 else
684 return 0;
ff4eb398
JH
685 }
686
a1fe7cea
JH
687 *sp = s;
688 return flags;
ff4eb398
JH
689}
690
945b524a
JH
691static const UV uv_max_div_10 = UV_MAX / 10;
692static const U8 uv_max_mod_10 = UV_MAX % 10;
693
3f7602fa
TC
694int
695Perl_grok_number_flags(pTHX_ const char *pv, STRLEN len, UV *valuep, U32 flags)
696{
60939fb8 697 const char *s = pv;
c4420975 698 const char * const send = pv + len;
ae776a2c 699 const char *d;
60939fb8 700 int numtype = 0;
60939fb8 701
3f7602fa 702 PERL_ARGS_ASSERT_GROK_NUMBER_FLAGS;
7918f24d 703
60939fb8
NC
704 while (s < send && isSPACE(*s))
705 s++;
706 if (s == send) {
707 return 0;
708 } else if (*s == '-') {
709 s++;
710 numtype = IS_NUMBER_NEG;
711 }
712 else if (*s == '+')
aa42a541 713 s++;
60939fb8
NC
714
715 if (s == send)
716 return 0;
717
ae776a2c 718 /* The first digit (after optional sign): note that might
8c12dc63 719 * also point to "infinity" or "nan", or "1.#INF". */
ae776a2c
JH
720 d = s;
721
8c12dc63 722 /* next must be digit or the radix separator or beginning of infinity/nan */
60939fb8
NC
723 if (isDIGIT(*s)) {
724 /* UVs are at least 32 bits, so the first 9 decimal digits cannot
725 overflow. */
726 UV value = *s - '0';
727 /* This construction seems to be more optimiser friendly.
728 (without it gcc does the isDIGIT test and the *s - '0' separately)
729 With it gcc on arm is managing 6 instructions (6 cycles) per digit.
730 In theory the optimiser could deduce how far to unroll the loop
731 before checking for overflow. */
58bb9ec3
NC
732 if (++s < send) {
733 int digit = *s - '0';
60939fb8
NC
734 if (digit >= 0 && digit <= 9) {
735 value = value * 10 + digit;
58bb9ec3
NC
736 if (++s < send) {
737 digit = *s - '0';
60939fb8
NC
738 if (digit >= 0 && digit <= 9) {
739 value = value * 10 + digit;
58bb9ec3
NC
740 if (++s < send) {
741 digit = *s - '0';
60939fb8
NC
742 if (digit >= 0 && digit <= 9) {
743 value = value * 10 + digit;
58bb9ec3
NC
744 if (++s < send) {
745 digit = *s - '0';
60939fb8
NC
746 if (digit >= 0 && digit <= 9) {
747 value = value * 10 + digit;
58bb9ec3
NC
748 if (++s < send) {
749 digit = *s - '0';
60939fb8
NC
750 if (digit >= 0 && digit <= 9) {
751 value = value * 10 + digit;
58bb9ec3
NC
752 if (++s < send) {
753 digit = *s - '0';
60939fb8
NC
754 if (digit >= 0 && digit <= 9) {
755 value = value * 10 + digit;
58bb9ec3
NC
756 if (++s < send) {
757 digit = *s - '0';
60939fb8
NC
758 if (digit >= 0 && digit <= 9) {
759 value = value * 10 + digit;
58bb9ec3
NC
760 if (++s < send) {
761 digit = *s - '0';
60939fb8
NC
762 if (digit >= 0 && digit <= 9) {
763 value = value * 10 + digit;
58bb9ec3 764 if (++s < send) {
60939fb8
NC
765 /* Now got 9 digits, so need to check
766 each time for overflow. */
58bb9ec3 767 digit = *s - '0';
60939fb8 768 while (digit >= 0 && digit <= 9
945b524a
JH
769 && (value < uv_max_div_10
770 || (value == uv_max_div_10
771 && digit <= uv_max_mod_10))) {
60939fb8 772 value = value * 10 + digit;
58bb9ec3
NC
773 if (++s < send)
774 digit = *s - '0';
60939fb8
NC
775 else
776 break;
777 }
778 if (digit >= 0 && digit <= 9
51bd16da 779 && (s < send)) {
60939fb8
NC
780 /* value overflowed.
781 skip the remaining digits, don't
782 worry about setting *valuep. */
783 do {
784 s++;
785 } while (s < send && isDIGIT(*s));
786 numtype |=
787 IS_NUMBER_GREATER_THAN_UV_MAX;
788 goto skip_value;
789 }
790 }
791 }
98994639 792 }
60939fb8
NC
793 }
794 }
795 }
796 }
797 }
798 }
799 }
800 }
801 }
802 }
803 }
98994639 804 }
60939fb8 805 }
98994639 806 }
60939fb8
NC
807 numtype |= IS_NUMBER_IN_UV;
808 if (valuep)
809 *valuep = value;
810
811 skip_value:
812 if (GROK_NUMERIC_RADIX(&s, send)) {
813 numtype |= IS_NUMBER_NOT_INT;
814 while (s < send && isDIGIT(*s)) /* optional digits after the radix */
815 s++;
98994639 816 }
60939fb8
NC
817 }
818 else if (GROK_NUMERIC_RADIX(&s, send)) {
819 numtype |= IS_NUMBER_NOT_INT | IS_NUMBER_IN_UV; /* valuep assigned below */
820 /* no digits before the radix means we need digits after it */
821 if (s < send && isDIGIT(*s)) {
822 do {
823 s++;
824 } while (s < send && isDIGIT(*s));
825 if (valuep) {
826 /* integer approximation is valid - it's 0. */
827 *valuep = 0;
828 }
98994639 829 }
60939fb8 830 else
ae776a2c 831 return 0;
ff4eb398 832 }
60939fb8 833
8c12dc63 834 if (s < send) {
60939fb8 835 /* we can have an optional exponent part */
305b8651 836 if (isALPHA_FOLD_EQ(*s, 'e')) {
60939fb8
NC
837 s++;
838 if (s < send && (*s == '-' || *s == '+'))
839 s++;
840 if (s < send && isDIGIT(*s)) {
841 do {
842 s++;
843 } while (s < send && isDIGIT(*s));
844 }
3f7602fa
TC
845 else if (flags & PERL_SCAN_TRAILING)
846 return numtype | IS_NUMBER_TRAILING;
60939fb8 847 else
3f7602fa
TC
848 return 0;
849
850 /* The only flag we keep is sign. Blow away any "it's UV" */
851 numtype &= IS_NUMBER_NEG;
852 numtype |= IS_NUMBER_NOT_INT;
60939fb8
NC
853 }
854 }
855 while (s < send && isSPACE(*s))
856 s++;
857 if (s >= send)
aa8b85de 858 return numtype;
60939fb8
NC
859 if (len == 10 && memEQ(pv, "0 but true", 10)) {
860 if (valuep)
861 *valuep = 0;
862 return IS_NUMBER_IN_UV;
863 }
8c12dc63
JH
864 /* We could be e.g. at "Inf" or "NaN", or at the "#" of "1.#INF". */
865 if ((s + 2 < send) && strchr("inqs#", toFOLD(*s))) {
866 /* Really detect inf/nan. Start at d, not s, since the above
867 * code might have already consumed the "1." or "1". */
868 int infnan = Perl_grok_infnan(&d, send);
869 if ((infnan & IS_NUMBER_INFINITY)) {
870 return (numtype | infnan); /* Keep sign for infinity. */
871 }
872 else if ((infnan & IS_NUMBER_NAN)) {
873 return (numtype | infnan) & ~IS_NUMBER_NEG; /* Clear sign for nan. */
874 }
875 }
3f7602fa
TC
876 else if (flags & PERL_SCAN_TRAILING) {
877 return numtype | IS_NUMBER_TRAILING;
878 }
879
60939fb8 880 return 0;
98994639
HS
881}
882
6313e544 883/*
d62b8c6a 884=for apidoc grok_atou
6313e544 885
d62b8c6a 886grok_atou is a safer replacement for atoi and strtol.
6313e544 887
d62b8c6a
JH
888grok_atou parses a C-style zero-byte terminated string, looking for
889a decimal unsigned integer.
338aa8b0 890
d62b8c6a
JH
891Returns the unsigned integer, if a valid value can be parsed
892from the beginning of the string.
f4379102 893
d62b8c6a 894Accepts only the decimal digits '0'..'9'.
6313e544 895
d62b8c6a
JH
896As opposed to atoi or strtol, grok_atou does NOT allow optional
897leading whitespace, or negative inputs. If such features are
898required, the calling code needs to explicitly implement those.
6313e544 899
d62b8c6a 900If a valid value cannot be parsed, returns either zero (if non-digits
75feedba 901are met before any digits) or UV_MAX (if the value overflows).
6313e544 902
d62b8c6a
JH
903Note that extraneous leading zeros also count as an overflow
904(meaning that only "0" is the zero).
338aa8b0 905
d62b8c6a 906On failure, the *endptr is also set to NULL, unless endptr is NULL.
338aa8b0
JH
907
908Trailing non-digit bytes are allowed if the endptr is non-NULL.
6313e544
JH
909On return the *endptr will contain the pointer to the first non-digit byte.
910
6313e544 911If the endptr is NULL, the first non-digit byte MUST be
f4379102 912the zero byte terminating the pv, or zero will be returned.
6313e544 913
d62b8c6a
JH
914Background: atoi has severe problems with illegal inputs, it cannot be
915used for incremental parsing, and therefore should be avoided
916atoi and strtol are also affected by locale settings, which can also be
917seen as a bug (global state controlled by user environment).
918
6313e544
JH
919=cut
920*/
921
75feedba 922UV
6313e544
JH
923Perl_grok_atou(const char *pv, const char** endptr)
924{
925 const char* s = pv;
926 const char** eptr;
927 const char* end2; /* Used in case endptr is NULL. */
75feedba 928 UV val = 0; /* The return value. */
6313e544
JH
929
930 PERL_ARGS_ASSERT_GROK_ATOU;
931
932 eptr = endptr ? endptr : &end2;
75feedba
JH
933 if (isDIGIT(*s)) {
934 /* Single-digit inputs are quite common. */
6313e544 935 val = *s++ - '0';
75feedba
JH
936 if (isDIGIT(*s)) {
937 /* Extra leading zeros cause overflow. */
938 if (val == 0) {
939 *eptr = NULL;
940 return UV_MAX;
941 }
942 while (isDIGIT(*s)) {
943 /* This could be unrolled like in grok_number(), but
944 * the expected uses of this are not speed-needy, and
945 * unlikely to need full 64-bitness. */
946 U8 digit = *s++ - '0';
945b524a
JH
947 if (val < uv_max_div_10 ||
948 (val == uv_max_div_10 && digit <= uv_max_mod_10)) {
75feedba
JH
949 val = val * 10 + digit;
950 } else {
6313e544 951 *eptr = NULL;
75feedba 952 return UV_MAX;
6313e544 953 }
6313e544
JH
954 }
955 }
75feedba
JH
956 }
957 if (s == pv) {
958 *eptr = NULL; /* If no progress, failed to parse anything. */
959 return 0;
6313e544
JH
960 }
961 if (endptr == NULL && *s) {
962 return 0; /* If endptr is NULL, no trailing non-digits allowed. */
963 }
964 *eptr = s;
965 return val;
966}
967
4801ca72 968STATIC NV
98994639
HS
969S_mulexp10(NV value, I32 exponent)
970{
971 NV result = 1.0;
972 NV power = 10.0;
973 bool negative = 0;
974 I32 bit;
975
976 if (exponent == 0)
977 return value;
659c4b96
DM
978 if (value == 0)
979 return (NV)0;
87032ba1 980
24866caa 981 /* On OpenVMS VAX we by default use the D_FLOAT double format,
67597c89 982 * and that format does not have *easy* capabilities [1] for
24866caa
CB
983 * overflowing doubles 'silently' as IEEE fp does. We also need
984 * to support G_FLOAT on both VAX and Alpha, and though the exponent
985 * range is much larger than D_FLOAT it still doesn't do silent
986 * overflow. Therefore we need to detect early whether we would
987 * overflow (this is the behaviour of the native string-to-float
988 * conversion routines, and therefore of native applications, too).
67597c89 989 *
24866caa
CB
990 * [1] Trying to establish a condition handler to trap floating point
991 * exceptions is not a good idea. */
87032ba1
JH
992
993 /* In UNICOS and in certain Cray models (such as T90) there is no
994 * IEEE fp, and no way at all from C to catch fp overflows gracefully.
995 * There is something you can do if you are willing to use some
996 * inline assembler: the instruction is called DFI-- but that will
997 * disable *all* floating point interrupts, a little bit too large
998 * a hammer. Therefore we need to catch potential overflows before
999 * it's too late. */
353813d9 1000
85bba25f 1001#if ((defined(VMS) && !defined(_IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP)
353813d9 1002 STMT_START {
c4420975 1003 const NV exp_v = log10(value);
353813d9
HS
1004 if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP)
1005 return NV_MAX;
1006 if (exponent < 0) {
1007 if (-(exponent + exp_v) >= NV_MAX_10_EXP)
1008 return 0.0;
1009 while (-exponent >= NV_MAX_10_EXP) {
1010 /* combination does not overflow, but 10^(-exponent) does */
1011 value /= 10;
1012 ++exponent;
1013 }
1014 }
1015 } STMT_END;
87032ba1
JH
1016#endif
1017
353813d9
HS
1018 if (exponent < 0) {
1019 negative = 1;
1020 exponent = -exponent;
b27804d8
DM
1021#ifdef NV_MAX_10_EXP
1022 /* for something like 1234 x 10^-309, the action of calculating
1023 * the intermediate value 10^309 then returning 1234 / (10^309)
1024 * will fail, since 10^309 becomes infinity. In this case try to
1025 * refactor it as 123 / (10^308) etc.
1026 */
1027 while (value && exponent > NV_MAX_10_EXP) {
1028 exponent--;
1029 value /= 10;
1030 }
1031#endif
353813d9 1032 }
98994639
HS
1033 for (bit = 1; exponent; bit <<= 1) {
1034 if (exponent & bit) {
1035 exponent ^= bit;
1036 result *= power;
236f0012
CB
1037 /* Floating point exceptions are supposed to be turned off,
1038 * but if we're obviously done, don't risk another iteration.
1039 */
1040 if (exponent == 0) break;
98994639
HS
1041 }
1042 power *= power;
1043 }
1044 return negative ? value / result : value * result;
1045}
1046
1047NV
1048Perl_my_atof(pTHX_ const char* s)
1049{
1050 NV x = 0.0;
1051#ifdef USE_LOCALE_NUMERIC
7918f24d
NC
1052 PERL_ARGS_ASSERT_MY_ATOF;
1053
a2287a13
KW
1054 {
1055 DECLARE_STORE_LC_NUMERIC_SET_TO_NEEDED();
d6ded950 1056 if (PL_numeric_radix_sv && IN_LC(LC_NUMERIC)) {
e4850248
KW
1057 const char *standard = NULL, *local = NULL;
1058 bool use_standard_radix;
98994639 1059
e4850248
KW
1060 /* Look through the string for the first thing that looks like a
1061 * decimal point: either the value in the current locale or the
1062 * standard fallback of '.'. The one which appears earliest in the
1063 * input string is the one that we should have atof look for. Note
1064 * that we have to determine this beforehand because on some
1065 * systems, Perl_atof2 is just a wrapper around the system's atof.
1066 * */
1067 standard = strchr(s, '.');
1068 local = strstr(s, SvPV_nolen(PL_numeric_radix_sv));
78787052 1069
e4850248 1070 use_standard_radix = standard && (!local || standard < local);
78787052 1071
e4850248
KW
1072 if (use_standard_radix)
1073 SET_NUMERIC_STANDARD();
78787052 1074
e4850248 1075 Perl_atof2(s, x);
78787052 1076
e4850248
KW
1077 if (use_standard_radix)
1078 SET_NUMERIC_LOCAL();
1079 }
1080 else
1081 Perl_atof2(s, x);
a2287a13
KW
1082 RESTORE_LC_NUMERIC();
1083 }
98994639 1084#else
a36244b7 1085 Perl_atof2(s, x);
98994639
HS
1086#endif
1087 return x;
1088}
1089
1090char*
1091Perl_my_atof2(pTHX_ const char* orig, NV* value)
1092{
20f6aaab 1093 NV result[3] = {0.0, 0.0, 0.0};
e1ec3a88 1094 const char* s = orig;
a36244b7 1095#ifdef USE_PERL_ATOF
20f6aaab 1096 UV accumulator[2] = {0,0}; /* before/after dp */
a36244b7 1097 bool negative = 0;
ae776a2c 1098 const char* send = s + strlen(orig); /* one past the last */
8194bf88 1099 bool seen_digit = 0;
20f6aaab
AS
1100 I32 exp_adjust[2] = {0,0};
1101 I32 exp_acc[2] = {-1, -1};
1102 /* the current exponent adjust for the accumulators */
98994639 1103 I32 exponent = 0;
8194bf88 1104 I32 seen_dp = 0;
20f6aaab
AS
1105 I32 digit = 0;
1106 I32 old_digit = 0;
8194bf88
DM
1107 I32 sig_digits = 0; /* noof significant digits seen so far */
1108
7918f24d
NC
1109 PERL_ARGS_ASSERT_MY_ATOF2;
1110
8194bf88
DM
1111/* There is no point in processing more significant digits
1112 * than the NV can hold. Note that NV_DIG is a lower-bound value,
1113 * while we need an upper-bound value. We add 2 to account for this;
1114 * since it will have been conservative on both the first and last digit.
1115 * For example a 32-bit mantissa with an exponent of 4 would have
1116 * exact values in the set
1117 * 4
1118 * 8
1119 * ..
1120 * 17179869172
1121 * 17179869176
1122 * 17179869180
1123 *
1124 * where for the purposes of calculating NV_DIG we would have to discount
1125 * both the first and last digit, since neither can hold all values from
1126 * 0..9; but for calculating the value we must examine those two digits.
1127 */
ffa277e5
EAS
1128#ifdef MAX_SIG_DIG_PLUS
1129 /* It is not necessarily the case that adding 2 to NV_DIG gets all the
1130 possible digits in a NV, especially if NVs are not IEEE compliant
1131 (e.g., long doubles on IRIX) - Allen <allens@cpan.org> */
1132# define MAX_SIG_DIGITS (NV_DIG+MAX_SIG_DIG_PLUS)
1133#else
1134# define MAX_SIG_DIGITS (NV_DIG+2)
1135#endif
8194bf88
DM
1136
1137/* the max number we can accumulate in a UV, and still safely do 10*N+9 */
1138#define MAX_ACCUMULATE ( (UV) ((UV_MAX - 9)/10))
98994639 1139
96a05aee
HS
1140 /* leading whitespace */
1141 while (isSPACE(*s))
1142 ++s;
1143
98994639
HS
1144 /* sign */
1145 switch (*s) {
1146 case '-':
1147 negative = 1;
924ba076 1148 /* FALLTHROUGH */
98994639
HS
1149 case '+':
1150 ++s;
1151 }
1152
ae776a2c
JH
1153 {
1154 const char *p0 = negative ? s - 1 : s;
1155 const char *p = p0;
8c12dc63
JH
1156 int infnan = grok_infnan(&p, send);
1157 if (infnan && p != p0) {
1158 /* If we can generate inf/nan directly, let's do so. */
1159#ifdef NV_INF
1160 if ((infnan & IS_NUMBER_INFINITY)) {
1161 *value = (infnan & IS_NUMBER_NEG) ? -NV_INF: NV_INF;
ae776a2c
JH
1162 return (char*)p;
1163 }
8c12dc63
JH
1164#endif
1165#ifdef NV_NAN
1166 if ((infnan & IS_NUMBER_NAN)) {
ae776a2c
JH
1167 *value = NV_NAN;
1168 return (char*)p;
1169 }
8c12dc63
JH
1170#endif
1171#ifdef Perl_strtod
1172 /* If still here, we didn't have either NV_INF or INV_NAN,
1173 * and can try falling back to native strtod/strtold.
1174 *
1175 * The native interface might not recognize all the possible
1176 * inf/nan strings Perl recognizes. What we can try
1177 * is to try faking the input. We will try inf/-inf/nan
1178 * as the most promising/portable input. */
1179 {
1180 const char* fake = NULL;
1181 char* endp;
1182 NV nv;
1183 if ((infnan & IS_NUMBER_INFINITY)) {
1184 fake = ((infnan & IS_NUMBER_NEG)) ? "-inf" : "inf";
1185 }
1186 else if ((infnan & IS_NUMBER_NAN)) {
1187 fake = "nan";
1188 }
1189 assert(fake);
1190 nv = Perl_strtod(fake, &endp);
1191 if (fake != endp) {
1192 if ((infnan & IS_NUMBER_INFINITY)) {
1193#ifdef Perl_isinf
1194 if (Perl_isinf(nv))
1195 *value = nv;
1196#else
1197 /* last resort, may generate SIGFPE */
1198 *value = Perl_exp((NV)1e9);
1199 if ((infnan & IS_NUMBER_NEG))
1200 *value = -*value;
1201#endif
1202 return (char*)p; /* p, not endp */
1203 }
1204 else if ((infnan & IS_NUMBER_NAN)) {
1205#ifdef Perl_isnan
1206 if (Perl_isnan(nv))
1207 *value = nv;
1208#else
1209 /* last resort, may generate SIGFPE */
1210 *value = Perl_log((NV)-1.0);
1211#endif
1212 return (char*)p; /* p, not endp */
1213 }
1214 }
ae776a2c 1215 }
8c12dc63 1216#endif /* #ifdef Perl_strtod */
2b54f59f 1217 }
ae776a2c 1218 }
2b54f59f 1219
8194bf88
DM
1220 /* we accumulate digits into an integer; when this becomes too
1221 * large, we add the total to NV and start again */
98994639 1222
8194bf88
DM
1223 while (1) {
1224 if (isDIGIT(*s)) {
1225 seen_digit = 1;
20f6aaab 1226 old_digit = digit;
8194bf88 1227 digit = *s++ - '0';
20f6aaab
AS
1228 if (seen_dp)
1229 exp_adjust[1]++;
98994639 1230
8194bf88
DM
1231 /* don't start counting until we see the first significant
1232 * digit, eg the 5 in 0.00005... */
1233 if (!sig_digits && digit == 0)
1234 continue;
1235
1236 if (++sig_digits > MAX_SIG_DIGITS) {
98994639 1237 /* limits of precision reached */
20f6aaab
AS
1238 if (digit > 5) {
1239 ++accumulator[seen_dp];
1240 } else if (digit == 5) {
1241 if (old_digit % 2) { /* round to even - Allen */
1242 ++accumulator[seen_dp];
1243 }
1244 }
1245 if (seen_dp) {
1246 exp_adjust[1]--;
1247 } else {
1248 exp_adjust[0]++;
1249 }
8194bf88 1250 /* skip remaining digits */
98994639 1251 while (isDIGIT(*s)) {
98994639 1252 ++s;
20f6aaab
AS
1253 if (! seen_dp) {
1254 exp_adjust[0]++;
1255 }
98994639
HS
1256 }
1257 /* warn of loss of precision? */
98994639 1258 }
8194bf88 1259 else {
20f6aaab 1260 if (accumulator[seen_dp] > MAX_ACCUMULATE) {
8194bf88 1261 /* add accumulator to result and start again */
20f6aaab
AS
1262 result[seen_dp] = S_mulexp10(result[seen_dp],
1263 exp_acc[seen_dp])
1264 + (NV)accumulator[seen_dp];
1265 accumulator[seen_dp] = 0;
1266 exp_acc[seen_dp] = 0;
98994639 1267 }
20f6aaab
AS
1268 accumulator[seen_dp] = accumulator[seen_dp] * 10 + digit;
1269 ++exp_acc[seen_dp];
98994639 1270 }
8194bf88 1271 }
e1ec3a88 1272 else if (!seen_dp && GROK_NUMERIC_RADIX(&s, send)) {
8194bf88 1273 seen_dp = 1;
20f6aaab 1274 if (sig_digits > MAX_SIG_DIGITS) {
c86f7df5 1275 do {
20f6aaab 1276 ++s;
c86f7df5 1277 } while (isDIGIT(*s));
20f6aaab
AS
1278 break;
1279 }
8194bf88
DM
1280 }
1281 else {
1282 break;
98994639
HS
1283 }
1284 }
1285
20f6aaab
AS
1286 result[0] = S_mulexp10(result[0], exp_acc[0]) + (NV)accumulator[0];
1287 if (seen_dp) {
1288 result[1] = S_mulexp10(result[1], exp_acc[1]) + (NV)accumulator[1];
1289 }
98994639 1290
305b8651 1291 if (seen_digit && (isALPHA_FOLD_EQ(*s, 'e'))) {
98994639
HS
1292 bool expnegative = 0;
1293
1294 ++s;
1295 switch (*s) {
1296 case '-':
1297 expnegative = 1;
924ba076 1298 /* FALLTHROUGH */
98994639
HS
1299 case '+':
1300 ++s;
1301 }
1302 while (isDIGIT(*s))
1303 exponent = exponent * 10 + (*s++ - '0');
1304 if (expnegative)
1305 exponent = -exponent;
1306 }
1307
20f6aaab
AS
1308
1309
98994639 1310 /* now apply the exponent */
20f6aaab
AS
1311
1312 if (seen_dp) {
1313 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0])
1314 + S_mulexp10(result[1],exponent-exp_adjust[1]);
1315 } else {
1316 result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]);
1317 }
98994639
HS
1318
1319 /* now apply the sign */
1320 if (negative)
20f6aaab 1321 result[2] = -result[2];
a36244b7 1322#endif /* USE_PERL_ATOF */
20f6aaab 1323 *value = result[2];
73d840c0 1324 return (char *)s;
98994639
HS
1325}
1326
5d34af89 1327/*
3d9d9213 1328=for apidoc isinfnan
5d34af89
JH
1329
1330Perl_isinfnan() is utility function that returns true if the NV
1331argument is either an infinity or a NaN, false otherwise. To test
1332in more detail, use Perl_isinf() and Perl_isnan().
1333
1334=cut
1335*/
1cd88304
JH
1336bool
1337Perl_isinfnan(NV nv)
1338{
1339#ifdef Perl_isinf
1340 if (Perl_isinf(nv))
1341 return TRUE;
1342#endif
1343#ifdef Perl_isnan
1344 if (Perl_isnan(nv))
1345 return TRUE;
1346#endif
1347 return FALSE;
1348}
1349
d67dac15
JH
1350#ifndef HAS_MODFL
1351/* C99 has truncl, pre-C99 Solaris had aintl */
1352# if defined(HAS_TRUNCL) && defined(HAS_COPYSIGNL)
1353long double
1354Perl_my_modfl(long double x, long double *ip)
1355{
1356 *ip = truncl(x);
1357 return (x == *ip ? copysignl(0.0L, x) : x - *ip);
1358}
1359# elif defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
55954f19
JH
1360long double
1361Perl_my_modfl(long double x, long double *ip)
1362{
1363 *ip = aintl(x);
1364 return (x == *ip ? copysignl(0.0L, x) : x - *ip);
1365}
d67dac15 1366# endif
55954f19
JH
1367#endif
1368
1369#if ! defined(HAS_FREXPL) && defined(HAS_ILOGBL) && defined(HAS_SCALBNL)
1370long double
1371Perl_my_frexpl(long double x, int *e) {
1372 *e = x == 0.0L ? 0 : ilogbl(x) + 1;
1373 return (scalbnl(x, -*e));
1374}
1375#endif
66610fdd
RGS
1376
1377/*
ed140128
AD
1378=for apidoc Perl_signbit
1379
1380Return a non-zero integer if the sign bit on an NV is set, and 0 if
1381it is not.
1382
1383If Configure detects this system has a signbit() that will work with
1384our NVs, then we just use it via the #define in perl.h. Otherwise,
8b7fad81
JH
1385fall back on this implementation. The main use of this function
1386is catching -0.0.
ed140128
AD
1387
1388Configure notes: This function is called 'Perl_signbit' instead of a
1389plain 'signbit' because it is easy to imagine a system having a signbit()
1390function or macro that doesn't happen to work with our particular choice
1391of NVs. We shouldn't just re-#define signbit as Perl_signbit and expect
1392the standard system headers to be happy. Also, this is a no-context
1393function (no pTHX_) because Perl_signbit() is usually re-#defined in
1394perl.h as a simple macro call to the system's signbit().
1395Users should just always call Perl_signbit().
1396
1397=cut
1398*/
1399#if !defined(HAS_SIGNBIT)
1400int
1401Perl_signbit(NV x) {
8b7fad81
JH
1402# ifdef Perl_fp_class_nzero
1403 if (x == 0)
1404 return Perl_fp_class_nzero(x);
8b7fad81 1405# endif
3585840c 1406 return (x < 0.0) ? 1 : 0;
ed140128
AD
1407}
1408#endif
1409
1410/*
66610fdd
RGS
1411 * Local variables:
1412 * c-indentation-style: bsd
1413 * c-basic-offset: 4
14d04a33 1414 * indent-tabs-mode: nil
66610fdd
RGS
1415 * End:
1416 *
14d04a33 1417 * ex: set ts=8 sts=4 sw=4 et:
37442d52 1418 */