forked from schacon/perl
/
numeric.c
1065 lines (961 loc) · 31.7 KB
/
numeric.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* numeric.c
*
* Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
* 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
*
*/
/*
* "That only makes eleven (plus one mislaid) and not fourteen, unless
* wizards count differently to other people."
*/
/*
=head1 Numeric functions
This file contains all the stuff needed by perl for manipulating numeric
values, including such things as replacements for the OS's atof() function
=cut
*/
#include "EXTERN.h"
#define PERL_IN_NUMERIC_C
#include "perl.h"
U32
Perl_cast_ulong(pTHX_ NV f)
{
PERL_UNUSED_CONTEXT;
if (f < 0.0)
return f < I32_MIN ? (U32) I32_MIN : (U32)(I32) f;
if (f < U32_MAX_P1) {
#if CASTFLAGS & 2
if (f < U32_MAX_P1_HALF)
return (U32) f;
f -= U32_MAX_P1_HALF;
return ((U32) f) | (1 + U32_MAX >> 1);
#else
return (U32) f;
#endif
}
return f > 0 ? U32_MAX : 0 /* NaN */;
}
I32
Perl_cast_i32(pTHX_ NV f)
{
PERL_UNUSED_CONTEXT;
if (f < I32_MAX_P1)
return f < I32_MIN ? I32_MIN : (I32) f;
if (f < U32_MAX_P1) {
#if CASTFLAGS & 2
if (f < U32_MAX_P1_HALF)
return (I32)(U32) f;
f -= U32_MAX_P1_HALF;
return (I32)(((U32) f) | (1 + U32_MAX >> 1));
#else
return (I32)(U32) f;
#endif
}
return f > 0 ? (I32)U32_MAX : 0 /* NaN */;
}
IV
Perl_cast_iv(pTHX_ NV f)
{
PERL_UNUSED_CONTEXT;
if (f < IV_MAX_P1)
return f < IV_MIN ? IV_MIN : (IV) f;
if (f < UV_MAX_P1) {
#if CASTFLAGS & 2
/* For future flexibility allowing for sizeof(UV) >= sizeof(IV) */
if (f < UV_MAX_P1_HALF)
return (IV)(UV) f;
f -= UV_MAX_P1_HALF;
return (IV)(((UV) f) | (1 + UV_MAX >> 1));
#else
return (IV)(UV) f;
#endif
}
return f > 0 ? (IV)UV_MAX : 0 /* NaN */;
}
UV
Perl_cast_uv(pTHX_ NV f)
{
PERL_UNUSED_CONTEXT;
if (f < 0.0)
return f < IV_MIN ? (UV) IV_MIN : (UV)(IV) f;
if (f < UV_MAX_P1) {
#if CASTFLAGS & 2
if (f < UV_MAX_P1_HALF)
return (UV) f;
f -= UV_MAX_P1_HALF;
return ((UV) f) | (1 + UV_MAX >> 1);
#else
return (UV) f;
#endif
}
return f > 0 ? UV_MAX : 0 /* NaN */;
}
/*
=for apidoc grok_bin
converts a string representing a binary number to numeric form.
On entry I<start> and I<*len> give the string to scan, I<*flags> gives
conversion flags, and I<result> should be NULL or a pointer to an NV.
The scan stops at the end of the string, or the first invalid character.
Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
invalid character will also trigger a warning.
On return I<*len> is set to the length of the scanned string,
and I<*flags> gives output flags.
If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
and nothing is written to I<*result>. If the value is > UV_MAX C<grok_bin>
returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
and writes the value to I<*result> (or the value is discarded if I<result>
is NULL).
The binary number may optionally be prefixed with "0b" or "b" unless
C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If
C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the binary
number may use '_' characters to separate digits.
=cut
*/
UV
Perl_grok_bin(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result) {
const char *s = start;
STRLEN len = *len_p;
UV value = 0;
NV value_nv = 0;
const UV max_div_2 = UV_MAX / 2;
const bool allow_underscores = (bool)(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
bool overflowed = FALSE;
char bit;
if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) {
/* strip off leading b or 0b.
for compatibility silently suffer "b" and "0b" as valid binary
numbers. */
if (len >= 1) {
if (s[0] == 'b') {
s++;
len--;
}
else if (len >= 2 && s[0] == '0' && s[1] == 'b') {
s+=2;
len-=2;
}
}
}
for (; len-- && (bit = *s); s++) {
if (bit == '0' || bit == '1') {
/* Write it in this wonky order with a goto to attempt to get the
compiler to make the common case integer-only loop pretty tight.
With gcc seems to be much straighter code than old scan_bin. */
redo:
if (!overflowed) {
if (value <= max_div_2) {
value = (value << 1) | (bit - '0');
continue;
}
/* Bah. We're just overflowed. */
if (ckWARN_d(WARN_OVERFLOW))
Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
"Integer overflow in binary number");
overflowed = TRUE;
value_nv = (NV) value;
}
value_nv *= 2.0;
/* If an NV has not enough bits in its mantissa to
* represent a UV this summing of small low-order numbers
* is a waste of time (because the NV cannot preserve
* the low-order bits anyway): we could just remember when
* did we overflow and in the end just multiply value_nv by the
* right amount. */
value_nv += (NV)(bit - '0');
continue;
}
if (bit == '_' && len && allow_underscores && (bit = s[1])
&& (bit == '0' || bit == '1'))
{
--len;
++s;
goto redo;
}
if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT) && ckWARN(WARN_DIGIT))
Perl_warner(aTHX_ packWARN(WARN_DIGIT),
"Illegal binary digit '%c' ignored", *s);
break;
}
if ( ( overflowed && value_nv > 4294967295.0)
#if UVSIZE > 4
|| (!overflowed && value > 0xffffffff )
#endif
) {
if (ckWARN(WARN_PORTABLE))
Perl_warner(aTHX_ packWARN(WARN_PORTABLE),
"Binary number > 0b11111111111111111111111111111111 non-portable");
}
*len_p = s - start;
if (!overflowed) {
*flags = 0;
return value;
}
*flags = PERL_SCAN_GREATER_THAN_UV_MAX;
if (result)
*result = value_nv;
return UV_MAX;
}
/*
=for apidoc grok_hex
converts a string representing a hex number to numeric form.
On entry I<start> and I<*len> give the string to scan, I<*flags> gives
conversion flags, and I<result> should be NULL or a pointer to an NV.
The scan stops at the end of the string, or the first invalid character.
Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
invalid character will also trigger a warning.
On return I<*len> is set to the length of the scanned string,
and I<*flags> gives output flags.
If the value is <= UV_MAX it is returned as a UV, the output flags are clear,
and nothing is written to I<*result>. If the value is > UV_MAX C<grok_hex>
returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
and writes the value to I<*result> (or the value is discarded if I<result>
is NULL).
The hex number may optionally be prefixed with "0x" or "x" unless
C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If
C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the hex
number may use '_' characters to separate digits.
=cut
*/
UV
Perl_grok_hex(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result) {
dVAR;
const char *s = start;
STRLEN len = *len_p;
UV value = 0;
NV value_nv = 0;
const UV max_div_16 = UV_MAX / 16;
const bool allow_underscores = (bool)(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
bool overflowed = FALSE;
if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) {
/* strip off leading x or 0x.
for compatibility silently suffer "x" and "0x" as valid hex numbers.
*/
if (len >= 1) {
if (s[0] == 'x') {
s++;
len--;
}
else if (len >= 2 && s[0] == '0' && s[1] == 'x') {
s+=2;
len-=2;
}
}
}
for (; len-- && *s; s++) {
const char *hexdigit = strchr(PL_hexdigit, *s);
if (hexdigit) {
/* Write it in this wonky order with a goto to attempt to get the
compiler to make the common case integer-only loop pretty tight.
With gcc seems to be much straighter code than old scan_hex. */
redo:
if (!overflowed) {
if (value <= max_div_16) {
value = (value << 4) | ((hexdigit - PL_hexdigit) & 15);
continue;
}
/* Bah. We're just overflowed. */
if (ckWARN_d(WARN_OVERFLOW))
Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
"Integer overflow in hexadecimal number");
overflowed = TRUE;
value_nv = (NV) value;
}
value_nv *= 16.0;
/* If an NV has not enough bits in its mantissa to
* represent a UV this summing of small low-order numbers
* is a waste of time (because the NV cannot preserve
* the low-order bits anyway): we could just remember when
* did we overflow and in the end just multiply value_nv by the
* right amount of 16-tuples. */
value_nv += (NV)((hexdigit - PL_hexdigit) & 15);
continue;
}
if (*s == '_' && len && allow_underscores && s[1]
&& (hexdigit = strchr(PL_hexdigit, s[1])))
{
--len;
++s;
goto redo;
}
if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT) && ckWARN(WARN_DIGIT))
Perl_warner(aTHX_ packWARN(WARN_DIGIT),
"Illegal hexadecimal digit '%c' ignored", *s);
break;
}
if ( ( overflowed && value_nv > 4294967295.0)
#if UVSIZE > 4
|| (!overflowed && value > 0xffffffff )
#endif
) {
if (ckWARN(WARN_PORTABLE))
Perl_warner(aTHX_ packWARN(WARN_PORTABLE),
"Hexadecimal number > 0xffffffff non-portable");
}
*len_p = s - start;
if (!overflowed) {
*flags = 0;
return value;
}
*flags = PERL_SCAN_GREATER_THAN_UV_MAX;
if (result)
*result = value_nv;
return UV_MAX;
}
/*
=for apidoc grok_oct
converts a string representing an octal number to numeric form.
On entry I<start> and I<*len> give the string to scan, I<*flags> gives
conversion flags, and I<result> should be NULL or a pointer to an NV.
The scan stops at the end of the string, or the first invalid character.
Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
invalid character will also trigger a warning.
On return I<*len> is set to the length of the scanned string,
and I<*flags> gives output flags.
If the value is <= UV_MAX it is returned as a UV, the output flags are clear,
and nothing is written to I<*result>. If the value is > UV_MAX C<grok_oct>
returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
and writes the value to I<*result> (or the value is discarded if I<result>
is NULL).
If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the octal
number may use '_' characters to separate digits.
=cut
*/
UV
Perl_grok_oct(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result) {
const char *s = start;
STRLEN len = *len_p;
UV value = 0;
NV value_nv = 0;
const UV max_div_8 = UV_MAX / 8;
const bool allow_underscores = (bool)(*flags & PERL_SCAN_ALLOW_UNDERSCORES);
bool overflowed = FALSE;
for (; len-- && *s; s++) {
/* gcc 2.95 optimiser not smart enough to figure that this subtraction
out front allows slicker code. */
int digit = *s - '0';
if (digit >= 0 && digit <= 7) {
/* Write it in this wonky order with a goto to attempt to get the
compiler to make the common case integer-only loop pretty tight.
*/
redo:
if (!overflowed) {
if (value <= max_div_8) {
value = (value << 3) | digit;
continue;
}
/* Bah. We're just overflowed. */
if (ckWARN_d(WARN_OVERFLOW))
Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
"Integer overflow in octal number");
overflowed = TRUE;
value_nv = (NV) value;
}
value_nv *= 8.0;
/* If an NV has not enough bits in its mantissa to
* represent a UV this summing of small low-order numbers
* is a waste of time (because the NV cannot preserve
* the low-order bits anyway): we could just remember when
* did we overflow and in the end just multiply value_nv by the
* right amount of 8-tuples. */
value_nv += (NV)digit;
continue;
}
if (digit == ('_' - '0') && len && allow_underscores
&& (digit = s[1] - '0') && (digit >= 0 && digit <= 7))
{
--len;
++s;
goto redo;
}
/* Allow \octal to work the DWIM way (that is, stop scanning
* as soon as non-octal characters are seen, complain only if
* someone seems to want to use the digits eight and nine). */
if (digit == 8 || digit == 9) {
if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT) && ckWARN(WARN_DIGIT))
Perl_warner(aTHX_ packWARN(WARN_DIGIT),
"Illegal octal digit '%c' ignored", *s);
}
break;
}
if ( ( overflowed && value_nv > 4294967295.0)
#if UVSIZE > 4
|| (!overflowed && value > 0xffffffff )
#endif
) {
if (ckWARN(WARN_PORTABLE))
Perl_warner(aTHX_ packWARN(WARN_PORTABLE),
"Octal number > 037777777777 non-portable");
}
*len_p = s - start;
if (!overflowed) {
*flags = 0;
return value;
}
*flags = PERL_SCAN_GREATER_THAN_UV_MAX;
if (result)
*result = value_nv;
return UV_MAX;
}
/*
=for apidoc scan_bin
For backwards compatibility. Use C<grok_bin> instead.
=for apidoc scan_hex
For backwards compatibility. Use C<grok_hex> instead.
=for apidoc scan_oct
For backwards compatibility. Use C<grok_oct> instead.
=cut
*/
NV
Perl_scan_bin(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
{
NV rnv;
I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
const UV ruv = grok_bin (start, &len, &flags, &rnv);
*retlen = len;
return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
}
NV
Perl_scan_oct(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
{
NV rnv;
I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
const UV ruv = grok_oct (start, &len, &flags, &rnv);
*retlen = len;
return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
}
NV
Perl_scan_hex(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
{
NV rnv;
I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
const UV ruv = grok_hex (start, &len, &flags, &rnv);
*retlen = len;
return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
}
/*
=for apidoc grok_numeric_radix
Scan and skip for a numeric decimal separator (radix).
=cut
*/
bool
Perl_grok_numeric_radix(pTHX_ const char **sp, const char *send)
{
#ifdef USE_LOCALE_NUMERIC
dVAR;
if (PL_numeric_radix_sv && IN_LOCALE) {
STRLEN len;
const char * const radix = SvPV(PL_numeric_radix_sv, len);
if (*sp + len <= send && memEQ(*sp, radix, len)) {
*sp += len;
return TRUE;
}
}
/* always try "." if numeric radix didn't match because
* we may have data from different locales mixed */
#endif
if (*sp < send && **sp == '.') {
++*sp;
return TRUE;
}
return FALSE;
}
/*
=for apidoc grok_number
Recognise (or not) a number. The type of the number is returned
(0 if unrecognised), otherwise it is a bit-ORed combination of
IS_NUMBER_IN_UV, IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT,
IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h).
If the value of the number can fit an in UV, it is returned in the *valuep
IS_NUMBER_IN_UV will be set to indicate that *valuep is valid, IS_NUMBER_IN_UV
will never be set unless *valuep is valid, but *valuep may have been assigned
to during processing even though IS_NUMBER_IN_UV is not set on return.
If valuep is NULL, IS_NUMBER_IN_UV will be set for the same cases as when
valuep is non-NULL, but no actual assignment (or SEGV) will occur.
IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing decimals were
seen (in which case *valuep gives the true value truncated to an integer), and
IS_NUMBER_NEG if the number is negative (in which case *valuep holds the
absolute value). IS_NUMBER_IN_UV is not set if e notation was used or the
number is larger than a UV.
=cut
*/
int
Perl_grok_number(pTHX_ const char *pv, STRLEN len, UV *valuep)
{
const char *s = pv;
const char * const send = pv + len;
const UV max_div_10 = UV_MAX / 10;
const char max_mod_10 = UV_MAX % 10;
int numtype = 0;
int sawinf = 0;
int sawnan = 0;
while (s < send && isSPACE(*s))
s++;
if (s == send) {
return 0;
} else if (*s == '-') {
s++;
numtype = IS_NUMBER_NEG;
}
else if (*s == '+')
s++;
if (s == send)
return 0;
/* next must be digit or the radix separator or beginning of infinity */
if (isDIGIT(*s)) {
/* UVs are at least 32 bits, so the first 9 decimal digits cannot
overflow. */
UV value = *s - '0';
/* This construction seems to be more optimiser friendly.
(without it gcc does the isDIGIT test and the *s - '0' separately)
With it gcc on arm is managing 6 instructions (6 cycles) per digit.
In theory the optimiser could deduce how far to unroll the loop
before checking for overflow. */
if (++s < send) {
int digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
digit = *s - '0';
if (digit >= 0 && digit <= 9) {
value = value * 10 + digit;
if (++s < send) {
/* Now got 9 digits, so need to check
each time for overflow. */
digit = *s - '0';
while (digit >= 0 && digit <= 9
&& (value < max_div_10
|| (value == max_div_10
&& digit <= max_mod_10))) {
value = value * 10 + digit;
if (++s < send)
digit = *s - '0';
else
break;
}
if (digit >= 0 && digit <= 9
&& (s < send)) {
/* value overflowed.
skip the remaining digits, don't
worry about setting *valuep. */
do {
s++;
} while (s < send && isDIGIT(*s));
numtype |=
IS_NUMBER_GREATER_THAN_UV_MAX;
goto skip_value;
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
numtype |= IS_NUMBER_IN_UV;
if (valuep)
*valuep = value;
skip_value:
if (GROK_NUMERIC_RADIX(&s, send)) {
numtype |= IS_NUMBER_NOT_INT;
while (s < send && isDIGIT(*s)) /* optional digits after the radix */
s++;
}
}
else if (GROK_NUMERIC_RADIX(&s, send)) {
numtype |= IS_NUMBER_NOT_INT | IS_NUMBER_IN_UV; /* valuep assigned below */
/* no digits before the radix means we need digits after it */
if (s < send && isDIGIT(*s)) {
do {
s++;
} while (s < send && isDIGIT(*s));
if (valuep) {
/* integer approximation is valid - it's 0. */
*valuep = 0;
}
}
else
return 0;
} else if (*s == 'I' || *s == 'i') {
s++; if (s == send || (*s != 'N' && *s != 'n')) return 0;
s++; if (s == send || (*s != 'F' && *s != 'f')) return 0;
s++; if (s < send && (*s == 'I' || *s == 'i')) {
s++; if (s == send || (*s != 'N' && *s != 'n')) return 0;
s++; if (s == send || (*s != 'I' && *s != 'i')) return 0;
s++; if (s == send || (*s != 'T' && *s != 't')) return 0;
s++; if (s == send || (*s != 'Y' && *s != 'y')) return 0;
s++;
}
sawinf = 1;
} else if (*s == 'N' || *s == 'n') {
/* XXX TODO: There are signaling NaNs and quiet NaNs. */
s++; if (s == send || (*s != 'A' && *s != 'a')) return 0;
s++; if (s == send || (*s != 'N' && *s != 'n')) return 0;
s++;
sawnan = 1;
} else
return 0;
if (sawinf) {
numtype &= IS_NUMBER_NEG; /* Keep track of sign */
numtype |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT;
} else if (sawnan) {
numtype &= IS_NUMBER_NEG; /* Keep track of sign */
numtype |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
} else if (s < send) {
/* we can have an optional exponent part */
if (*s == 'e' || *s == 'E') {
/* The only flag we keep is sign. Blow away any "it's UV" */
numtype &= IS_NUMBER_NEG;
numtype |= IS_NUMBER_NOT_INT;
s++;
if (s < send && (*s == '-' || *s == '+'))
s++;
if (s < send && isDIGIT(*s)) {
do {
s++;
} while (s < send && isDIGIT(*s));
}
else
return 0;
}
}
while (s < send && isSPACE(*s))
s++;
if (s >= send)
return numtype;
if (len == 10 && memEQ(pv, "0 but true", 10)) {
if (valuep)
*valuep = 0;
return IS_NUMBER_IN_UV;
}
return 0;
}
STATIC NV
S_mulexp10(NV value, I32 exponent)
{
NV result = 1.0;
NV power = 10.0;
bool negative = 0;
I32 bit;
if (exponent == 0)
return value;
if (value == 0)
return (NV)0;
/* On OpenVMS VAX we by default use the D_FLOAT double format,
* and that format does not have *easy* capabilities [1] for
* overflowing doubles 'silently' as IEEE fp does. We also need
* to support G_FLOAT on both VAX and Alpha, and though the exponent
* range is much larger than D_FLOAT it still doesn't do silent
* overflow. Therefore we need to detect early whether we would
* overflow (this is the behaviour of the native string-to-float
* conversion routines, and therefore of native applications, too).
*
* [1] Trying to establish a condition handler to trap floating point
* exceptions is not a good idea. */
/* In UNICOS and in certain Cray models (such as T90) there is no
* IEEE fp, and no way at all from C to catch fp overflows gracefully.
* There is something you can do if you are willing to use some
* inline assembler: the instruction is called DFI-- but that will
* disable *all* floating point interrupts, a little bit too large
* a hammer. Therefore we need to catch potential overflows before
* it's too late. */
#if ((defined(VMS) && !defined(__IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP)
STMT_START {
const NV exp_v = log10(value);
if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP)
return NV_MAX;
if (exponent < 0) {
if (-(exponent + exp_v) >= NV_MAX_10_EXP)
return 0.0;
while (-exponent >= NV_MAX_10_EXP) {
/* combination does not overflow, but 10^(-exponent) does */
value /= 10;
++exponent;
}
}
} STMT_END;
#endif
if (exponent < 0) {
negative = 1;
exponent = -exponent;
}
for (bit = 1; exponent; bit <<= 1) {
if (exponent & bit) {
exponent ^= bit;
result *= power;
/* Floating point exceptions are supposed to be turned off,
* but if we're obviously done, don't risk another iteration.
*/
if (exponent == 0) break;
}
power *= power;
}
return negative ? value / result : value * result;
}
NV
Perl_my_atof(pTHX_ const char* s)
{
NV x = 0.0;
#ifdef USE_LOCALE_NUMERIC
dVAR;
if (PL_numeric_local && IN_LOCALE) {
NV y;
/* Scan the number twice; once using locale and once without;
* choose the larger result (in absolute value). */
Perl_atof2(s, x);
SET_NUMERIC_STANDARD();
Perl_atof2(s, y);
SET_NUMERIC_LOCAL();
if ((y < 0.0 && y < x) || (y > 0.0 && y > x))
return y;
}
else
Perl_atof2(s, x);
#else
Perl_atof2(s, x);
#endif
return x;
}
char*
Perl_my_atof2(pTHX_ const char* orig, NV* value)
{
NV result[3] = {0.0, 0.0, 0.0};
const char* s = orig;
#ifdef USE_PERL_ATOF
UV accumulator[2] = {0,0}; /* before/after dp */
bool negative = 0;
const char* send = s + strlen(orig) - 1;
bool seen_digit = 0;
I32 exp_adjust[2] = {0,0};
I32 exp_acc[2] = {-1, -1};
/* the current exponent adjust for the accumulators */
I32 exponent = 0;
I32 seen_dp = 0;
I32 digit = 0;
I32 old_digit = 0;
I32 sig_digits = 0; /* noof significant digits seen so far */
/* There is no point in processing more significant digits
* than the NV can hold. Note that NV_DIG is a lower-bound value,
* while we need an upper-bound value. We add 2 to account for this;
* since it will have been conservative on both the first and last digit.
* For example a 32-bit mantissa with an exponent of 4 would have
* exact values in the set
* 4
* 8
* ..
* 17179869172
* 17179869176
* 17179869180
*
* where for the purposes of calculating NV_DIG we would have to discount
* both the first and last digit, since neither can hold all values from
* 0..9; but for calculating the value we must examine those two digits.
*/
#define MAX_SIG_DIGITS (NV_DIG+2)
/* the max number we can accumulate in a UV, and still safely do 10*N+9 */
#define MAX_ACCUMULATE ( (UV) ((UV_MAX - 9)/10))
/* leading whitespace */
while (isSPACE(*s))
++s;
/* sign */
switch (*s) {
case '-':
negative = 1;
/* fall through */
case '+':
++s;
}
/* punt to strtod for NaN/Inf; if no support for it there, tough luck */
#ifdef HAS_STRTOD
if (*s == 'n' || *s == 'N' || *s == 'i' || *s == 'I') {
const char *p = negative ? s - 1 : s;
char *endp;
NV rslt;
rslt = strtod(p, &endp);
if (endp != p) {
*value = rslt;
return (char *)endp;
}
}
#endif
/* we accumulate digits into an integer; when this becomes too
* large, we add the total to NV and start again */
while (1) {
if (isDIGIT(*s)) {
seen_digit = 1;
old_digit = digit;
digit = *s++ - '0';
if (seen_dp)
exp_adjust[1]++;
/* don't start counting until we see the first significant
* digit, eg the 5 in 0.00005... */
if (!sig_digits && digit == 0)
continue;
if (++sig_digits > MAX_SIG_DIGITS) {
/* limits of precision reached */
if (digit > 5) {
++accumulator[seen_dp];
} else if (digit == 5) {
if (old_digit % 2) { /* round to even - Allen */
++accumulator[seen_dp];
}
}
if (seen_dp) {
exp_adjust[1]--;
} else {
exp_adjust[0]++;
}
/* skip remaining digits */
while (isDIGIT(*s)) {
++s;
if (! seen_dp) {
exp_adjust[0]++;
}
}
/* warn of loss of precision? */
}
else {
if (accumulator[seen_dp] > MAX_ACCUMULATE) {
/* add accumulator to result and start again */
result[seen_dp] = S_mulexp10(result[seen_dp],
exp_acc[seen_dp])
+ (NV)accumulator[seen_dp];
accumulator[seen_dp] = 0;
exp_acc[seen_dp] = 0;
}
accumulator[seen_dp] = accumulator[seen_dp] * 10 + digit;
++exp_acc[seen_dp];
}
}
else if (!seen_dp && GROK_NUMERIC_RADIX(&s, send)) {
seen_dp = 1;
if (sig_digits > MAX_SIG_DIGITS) {
do {
++s;
} while (isDIGIT(*s));
break;
}
}
else {
break;
}
}
result[0] = S_mulexp10(result[0], exp_acc[0]) + (NV)accumulator[0];
if (seen_dp) {
result[1] = S_mulexp10(result[1], exp_acc[1]) + (NV)accumulator[1];
}
if (seen_digit && (*s == 'e' || *s == 'E')) {
bool expnegative = 0;
++s;
switch (*s) {
case '-':
expnegative = 1;
/* fall through */
case '+':
++s;
}
while (isDIGIT(*s))
exponent = exponent * 10 + (*s++ - '0');
if (expnegative)
exponent = -exponent;
}
/* now apply the exponent */
if (seen_dp) {
result[2] = S_mulexp10(result[0],exponent+exp_adjust[0])
+ S_mulexp10(result[1],exponent-exp_adjust[1]);
} else {
result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]);
}
/* now apply the sign */