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Issue 10963: Fix the mac build to add dmg_fp to the libbase.a. (Closed)
Patch Set: Created 12 years, 1 month ago
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1 /****************************************************************
2 *
3 * The author of this software is David M. Gay.
4 *
5 * Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose without fee is hereby granted, provided that this entire notice
9 * is included in all copies of any software which is or includes a copy
10 * or modification of this software and in all copies of the supporting
11 * documentation for such software.
12 *
13 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
14 * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY
15 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
16 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
17 *
18 ***************************************************************/
19
20 /* Please send bug reports to David M. Gay (dmg at acm dot org,
21 * with " at " changed at "@" and " dot " changed to "."). */
22
23 /* On a machine with IEEE extended-precision registers, it is
24 * necessary to specify double-precision (53-bit) rounding precision
25 * before invoking strtod or dtoa. If the machine uses (the equivalent
26 * of) Intel 80x87 arithmetic, the call
27 * _control87(PC_53, MCW_PC);
28 * does this with many compilers. Whether this or another call is
29 * appropriate depends on the compiler; for this to work, it may be
30 * necessary to #include "float.h" or another system-dependent header
31 * file.
32 */
33
34 /* strtod for IEEE-, VAX-, and IBM-arithmetic machines.
35 *
36 * This strtod returns a nearest machine number to the input decimal
37 * string (or sets errno to ERANGE). With IEEE arithmetic, ties are
38 * broken by the IEEE round-even rule. Otherwise ties are broken by
39 * biased rounding (add half and chop).
40 *
41 * Inspired loosely by William D. Clinger's paper "How to Read Floating
42 * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 92-101].
43 *
44 * Modifications:
45 *
46 * 1. We only require IEEE, IBM, or VAX double-precision
47 * arithmetic (not IEEE double-extended).
48 * 2. We get by with floating-point arithmetic in a case that
49 * Clinger missed -- when we're computing d * 10^n
50 * for a small integer d and the integer n is not too
51 * much larger than 22 (the maximum integer k for which
52 * we can represent 10^k exactly), we may be able to
53 * compute (d*10^k) * 10^(e-k) with just one roundoff.
54 * 3. Rather than a bit-at-a-time adjustment of the binary
55 * result in the hard case, we use floating-point
56 * arithmetic to determine the adjustment to within
57 * one bit; only in really hard cases do we need to
58 * compute a second residual.
59 * 4. Because of 3., we don't need a large table of powers of 10
60 * for ten-to-e (just some small tables, e.g. of 10^k
61 * for 0 <= k <= 22).
62 */
63
64 /*
65 * #define IEEE_8087 for IEEE-arithmetic machines where the least
66 * significant byte has the lowest address.
67 * #define IEEE_MC68k for IEEE-arithmetic machines where the most
68 * significant byte has the lowest address.
69 * #define Long int on machines with 32-bit ints and 64-bit longs.
70 * #define IBM for IBM mainframe-style floating-point arithmetic.
71 * #define VAX for VAX-style floating-point arithmetic (D_floating).
72 * #define No_leftright to omit left-right logic in fast floating-point
73 * computation of dtoa.
74 * #define Honor_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3
75 * and strtod and dtoa should round accordingly. Unless Trust_FLT_ROUNDS
76 * is also #defined, fegetround() will be queried for the rounding mode.
77 * Note that both FLT_ROUNDS and fegetround() are specified by the C99
78 * standard (and are specified to be consistent, with fesetround()
79 * affecting the value of FLT_ROUNDS), but that some (Linux) systems
80 * do not work correctly in this regard, so using fegetround() is more
81 * portable than using FLT_FOUNDS directly.
82 * #define Check_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3
83 * and Honor_FLT_ROUNDS is not #defined.
84 * #define RND_PRODQUOT to use rnd_prod and rnd_quot (assembly routines
85 * that use extended-precision instructions to compute rounded
86 * products and quotients) with IBM.
87 * #define ROUND_BIASED for IEEE-format with biased rounding.
88 * #define Inaccurate_Divide for IEEE-format with correctly rounded
89 * products but inaccurate quotients, e.g., for Intel i860.
90 * #define NO_LONG_LONG on machines that do not have a "long long"
91 * integer type (of >= 64 bits). On such machines, you can
92 * #define Just_16 to store 16 bits per 32-bit Long when doing
93 * high-precision integer arithmetic. Whether this speeds things
94 * up or slows things down depends on the machine and the number
95 * being converted. If long long is available and the name is
96 * something other than "long long", #define Llong to be the name,
97 * and if "unsigned Llong" does not work as an unsigned version of
98 * Llong, #define #ULLong to be the corresponding unsigned type.
99 * #define KR_headers for old-style C function headers.
100 * #define Bad_float_h if your system lacks a float.h or if it does not
101 * define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP,
102 * FLT_RADIX, FLT_ROUNDS, and DBL_MAX.
103 * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n)
104 * if memory is available and otherwise does something you deem
105 * appropriate. If MALLOC is undefined, malloc will be invoked
106 * directly -- and assumed always to succeed.
107 * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
108 * memory allocations from a private pool of memory when possible.
109 * When used, the private pool is PRIVATE_MEM bytes long: 2304 bytes,
110 * unless #defined to be a different length. This default length
111 * suffices to get rid of MALLOC calls except for unusual cases,
112 * such as decimal-to-binary conversion of a very long string of
113 * digits. The longest string dtoa can return is about 751 bytes
114 * long. For conversions by strtod of strings of 800 digits and
115 * all dtoa conversions in single-threaded executions with 8-byte
116 * pointers, PRIVATE_MEM >= 7400 appears to suffice; with 4-byte
117 * pointers, PRIVATE_MEM >= 7112 appears adequate.
118 * #define NO_INFNAN_CHECK if you do not wish to have INFNAN_CHECK
119 * #defined automatically on IEEE systems. On such systems,
120 * when INFNAN_CHECK is #defined, strtod checks
121 * for Infinity and NaN (case insensitively). On some systems
122 * (e.g., some HP systems), it may be necessary to #define NAN_WORD0
123 * appropriately -- to the most significant word of a quiet NaN.
124 * (On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.)
125 * When INFNAN_CHECK is #defined and No_Hex_NaN is not #defined,
126 * strtod also accepts (case insensitively) strings of the form
127 * NaN(x), where x is a string of hexadecimal digits and spaces;
128 * if there is only one string of hexadecimal digits, it is taken
129 * for the 52 fraction bits of the resulting NaN; if there are two
130 * or more strings of hex digits, the first is for the high 20 bits,
131 * the second and subsequent for the low 32 bits, with intervening
132 * white space ignored; but if this results in none of the 52
133 * fraction bits being on (an IEEE Infinity symbol), then NAN_WORD0
134 * and NAN_WORD1 are used instead.
135 * #define MULTIPLE_THREADS if the system offers preemptively scheduled
136 * multiple threads. In this case, you must provide (or suitably
137 * #define) two locks, acquired by ACQUIRE_DTOA_LOCK(n) and freed
138 * by FREE_DTOA_LOCK(n) for n = 0 or 1. (The second lock, accessed
139 * in pow5mult, ensures lazy evaluation of only one copy of high
140 * powers of 5; omitting this lock would introduce a small
141 * probability of wasting memory, but would otherwise be harmless.)
142 * You must also invoke freedtoa(s) to free the value s returned by
143 * dtoa. You may do so whether or not MULTIPLE_THREADS is #defined.
144 * #define NO_IEEE_Scale to disable new (Feb. 1997) logic in strtod that
145 * avoids underflows on inputs whose result does not underflow.
146 * If you #define NO_IEEE_Scale on a machine that uses IEEE-format
147 * floating-point numbers and flushes underflows to zero rather
148 * than implementing gradual underflow, then you must also #define
149 * Sudden_Underflow.
150 * #define YES_ALIAS to permit aliasing certain double values with
151 * arrays of ULongs. This leads to slightly better code with
152 * some compilers and was always used prior to 19990916, but it
153 * is not strictly legal and can cause trouble with aggressively
154 * optimizing compilers (e.g., gcc 2.95.1 under -O2).
155 * #define USE_LOCALE to use the current locale's decimal_point value.
156 * #define SET_INEXACT if IEEE arithmetic is being used and extra
157 * computation should be done to set the inexact flag when the
158 * result is inexact and avoid setting inexact when the result
159 * is exact. In this case, dtoa.c must be compiled in
160 * an environment, perhaps provided by #include "dtoa.c" in a
161 * suitable wrapper, that defines two functions,
162 * int get_inexact(void);
163 * void clear_inexact(void);
164 * such that get_inexact() returns a nonzero value if the
165 * inexact bit is already set, and clear_inexact() sets the
166 * inexact bit to 0. When SET_INEXACT is #defined, strtod
167 * also does extra computations to set the underflow and overflow
168 * flags when appropriate (i.e., when the result is tiny and
169 * inexact or when it is a numeric value rounded to +-infinity).
170 * #define NO_ERRNO if strtod should not assign errno = ERANGE when
171 * the result overflows to +-Infinity or underflows to 0.
172 */
173
174 #ifndef Long
175 #define Long long
176 #endif
177 #ifndef ULong
178 typedef unsigned Long ULong;
179 #endif
180
181 #ifdef DEBUG
182 #include "stdio.h"
183 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
184 #endif
185
186 #include "stdlib.h"
187 #include "string.h"
188
189 #ifdef USE_LOCALE
190 #include "locale.h"
191 #endif
192
193 #ifdef MALLOC
194 #ifdef KR_headers
195 extern char *MALLOC();
196 #else
197 extern void *MALLOC(size_t);
198 #endif
199 #else
200 #define MALLOC malloc
201 #endif
202
203 #ifndef Omit_Private_Memory
204 #ifndef PRIVATE_MEM
205 #define PRIVATE_MEM 2304
206 #endif
207 #define PRIVATE_mem ((PRIVATE_MEM+sizeof(double)-1)/sizeof(double))
208 static double private_mem[PRIVATE_mem], *pmem_next = private_mem;
209 #endif
210
211 #undef IEEE_Arith
212 #undef Avoid_Underflow
213 #ifdef IEEE_MC68k
214 #define IEEE_Arith
215 #endif
216 #ifdef IEEE_8087
217 #define IEEE_Arith
218 #endif
219
220 #ifdef IEEE_Arith
221 #ifndef NO_INFNAN_CHECK
222 #undef INFNAN_CHECK
223 #define INFNAN_CHECK
224 #endif
225 #else
226 #undef INFNAN_CHECK
227 #endif
228
229 #include "errno.h"
230
231 #ifdef Bad_float_h
232
233 #ifdef IEEE_Arith
234 #define DBL_DIG 15
235 #define DBL_MAX_10_EXP 308
236 #define DBL_MAX_EXP 1024
237 #define FLT_RADIX 2
238 #endif /*IEEE_Arith*/
239
240 #ifdef IBM
241 #define DBL_DIG 16
242 #define DBL_MAX_10_EXP 75
243 #define DBL_MAX_EXP 63
244 #define FLT_RADIX 16
245 #define DBL_MAX 7.2370055773322621e+75
246 #endif
247
248 #ifdef VAX
249 #define DBL_DIG 16
250 #define DBL_MAX_10_EXP 38
251 #define DBL_MAX_EXP 127
252 #define FLT_RADIX 2
253 #define DBL_MAX 1.7014118346046923e+38
254 #endif
255
256 #ifndef LONG_MAX
257 #define LONG_MAX 2147483647
258 #endif
259
260 #else /* ifndef Bad_float_h */
261 #include "float.h"
262 #endif /* Bad_float_h */
263
264 #ifndef __MATH_H__
265 #include "math.h"
266 #endif
267
268 namespace dmg_fp {
269
270 #ifndef CONST
271 #ifdef KR_headers
272 #define CONST /* blank */
273 #else
274 #define CONST const
275 #endif
276 #endif
277
278 #if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1
279 Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined.
280 #endif
281
282 typedef union { double d; ULong L[2]; } U;
283
284 #ifdef YES_ALIAS
285 #define dval(x) x
286 #ifdef IEEE_8087
287 #define word0(x) ((ULong *)&x)[1]
288 #define word1(x) ((ULong *)&x)[0]
289 #else
290 #define word0(x) ((ULong *)&x)[0]
291 #define word1(x) ((ULong *)&x)[1]
292 #endif
293 #else
294 #ifdef IEEE_8087
295 #define word0(x) ((U*)&x)->L[1]
296 #define word1(x) ((U*)&x)->L[0]
297 #else
298 #define word0(x) ((U*)&x)->L[0]
299 #define word1(x) ((U*)&x)->L[1]
300 #endif
301 #define dval(x) ((U*)&x)->d
302 #endif
303
304 /* The following definition of Storeinc is appropriate for MIPS processors.
305 * An alternative that might be better on some machines is
306 * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
307 */
308 #if defined(IEEE_8087) + defined(VAX)
309 #define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \
310 ((unsigned short *)a)[0] = (unsigned short)c, a++)
311 #else
312 #define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \
313 ((unsigned short *)a)[1] = (unsigned short)c, a++)
314 #endif
315
316 /* #define P DBL_MANT_DIG */
317 /* Ten_pmax = floor(P*log(2)/log(5)) */
318 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
319 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
320 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
321
322 #ifdef IEEE_Arith
323 #define Exp_shift 20
324 #define Exp_shift1 20
325 #define Exp_msk1 0x100000
326 #define Exp_msk11 0x100000
327 #define Exp_mask 0x7ff00000
328 #define P 53
329 #define Bias 1023
330 #define Emin (-1022)
331 #define Exp_1 0x3ff00000
332 #define Exp_11 0x3ff00000
333 #define Ebits 11
334 #define Frac_mask 0xfffff
335 #define Frac_mask1 0xfffff
336 #define Ten_pmax 22
337 #define Bletch 0x10
338 #define Bndry_mask 0xfffff
339 #define Bndry_mask1 0xfffff
340 #define LSB 1
341 #define Sign_bit 0x80000000
342 #define Log2P 1
343 #define Tiny0 0
344 #define Tiny1 1
345 #define Quick_max 14
346 #define Int_max 14
347 #ifndef NO_IEEE_Scale
348 #define Avoid_Underflow
349 #ifdef Flush_Denorm /* debugging option */
350 #undef Sudden_Underflow
351 #endif
352 #endif
353
354 #ifndef Flt_Rounds
355 #ifdef FLT_ROUNDS
356 #define Flt_Rounds FLT_ROUNDS
357 #else
358 #define Flt_Rounds 1
359 #endif
360 #endif /*Flt_Rounds*/
361
362 #ifdef Honor_FLT_ROUNDS
363 #undef Check_FLT_ROUNDS
364 #define Check_FLT_ROUNDS
365 #else
366 #define Rounding Flt_Rounds
367 #endif
368
369 #else /* ifndef IEEE_Arith */
370 #undef Check_FLT_ROUNDS
371 #undef Honor_FLT_ROUNDS
372 #undef SET_INEXACT
373 #undef Sudden_Underflow
374 #define Sudden_Underflow
375 #ifdef IBM
376 #undef Flt_Rounds
377 #define Flt_Rounds 0
378 #define Exp_shift 24
379 #define Exp_shift1 24
380 #define Exp_msk1 0x1000000
381 #define Exp_msk11 0x1000000
382 #define Exp_mask 0x7f000000
383 #define P 14
384 #define Bias 65
385 #define Exp_1 0x41000000
386 #define Exp_11 0x41000000
387 #define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */
388 #define Frac_mask 0xffffff
389 #define Frac_mask1 0xffffff
390 #define Bletch 4
391 #define Ten_pmax 22
392 #define Bndry_mask 0xefffff
393 #define Bndry_mask1 0xffffff
394 #define LSB 1
395 #define Sign_bit 0x80000000
396 #define Log2P 4
397 #define Tiny0 0x100000
398 #define Tiny1 0
399 #define Quick_max 14
400 #define Int_max 15
401 #else /* VAX */
402 #undef Flt_Rounds
403 #define Flt_Rounds 1
404 #define Exp_shift 23
405 #define Exp_shift1 7
406 #define Exp_msk1 0x80
407 #define Exp_msk11 0x800000
408 #define Exp_mask 0x7f80
409 #define P 56
410 #define Bias 129
411 #define Exp_1 0x40800000
412 #define Exp_11 0x4080
413 #define Ebits 8
414 #define Frac_mask 0x7fffff
415 #define Frac_mask1 0xffff007f
416 #define Ten_pmax 24
417 #define Bletch 2
418 #define Bndry_mask 0xffff007f
419 #define Bndry_mask1 0xffff007f
420 #define LSB 0x10000
421 #define Sign_bit 0x8000
422 #define Log2P 1
423 #define Tiny0 0x80
424 #define Tiny1 0
425 #define Quick_max 15
426 #define Int_max 15
427 #endif /* IBM, VAX */
428 #endif /* IEEE_Arith */
429
430 #ifndef IEEE_Arith
431 #define ROUND_BIASED
432 #endif
433
434 #ifdef RND_PRODQUOT
435 #define rounded_product(a,b) a = rnd_prod(a, b)
436 #define rounded_quotient(a,b) a = rnd_quot(a, b)
437 #ifdef KR_headers
438 extern double rnd_prod(), rnd_quot();
439 #else
440 extern double rnd_prod(double, double), rnd_quot(double, double);
441 #endif
442 #else
443 #define rounded_product(a,b) a *= b
444 #define rounded_quotient(a,b) a /= b
445 #endif
446
447 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
448 #define Big1 0xffffffff
449
450 #ifndef Pack_32
451 #define Pack_32
452 #endif
453
454 #ifdef KR_headers
455 #define FFFFFFFF ((((unsigned long)0xffff)<<16)|(unsigned long)0xffff)
456 #else
457 #define FFFFFFFF 0xffffffffUL
458 #endif
459
460 #ifdef NO_LONG_LONG
461 #undef ULLong
462 #ifdef Just_16
463 #undef Pack_32
464 /* When Pack_32 is not defined, we store 16 bits per 32-bit Long.
465 * This makes some inner loops simpler and sometimes saves work
466 * during multiplications, but it often seems to make things slightly
467 * slower. Hence the default is now to store 32 bits per Long.
468 */
469 #endif
470 #else /* long long available */
471 #ifndef Llong
472 #define Llong long long
473 #endif
474 #ifndef ULLong
475 #define ULLong unsigned Llong
476 #endif
477 #endif /* NO_LONG_LONG */
478
479 #ifndef MULTIPLE_THREADS
480 #define ACQUIRE_DTOA_LOCK(n) /*nothing*/
481 #define FREE_DTOA_LOCK(n) /*nothing*/
482 #endif
483
484 #define Kmax 15
485
486 double strtod(const char *s00, char **se);
487 char *dtoa(double d, int mode, int ndigits,
488 int *decpt, int *sign, char **rve);
489
490 struct
491 Bigint {
492 struct Bigint *next;
493 int k, maxwds, sign, wds;
494 ULong x[1];
495 };
496
497 typedef struct Bigint Bigint;
498
499 static Bigint *freelist[Kmax+1];
500
501 static Bigint *
502 Balloc
503 #ifdef KR_headers
504 (k) int k;
505 #else
506 (int k)
507 #endif
508 {
509 int x;
510 Bigint *rv;
511 #ifndef Omit_Private_Memory
512 unsigned int len;
513 #endif
514
515 ACQUIRE_DTOA_LOCK(0);
516 if (rv = freelist[k]) {
517 freelist[k] = rv->next;
518 }
519 else {
520 x = 1 << k;
521 #ifdef Omit_Private_Memory
522 rv = (Bigint *)MALLOC(sizeof(Bigint) + (x-1)*sizeof(ULong));
523 #else
524 len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1 )
525 /sizeof(double);
526 if (pmem_next - private_mem + len <= PRIVATE_mem) {
527 rv = (Bigint*)pmem_next;
528 pmem_next += len;
529 }
530 else
531 rv = (Bigint*)MALLOC(len*sizeof(double));
532 #endif
533 rv->k = k;
534 rv->maxwds = x;
535 }
536 FREE_DTOA_LOCK(0);
537 rv->sign = rv->wds = 0;
538 return rv;
539 }
540
541 static void
542 Bfree
543 #ifdef KR_headers
544 (v) Bigint *v;
545 #else
546 (Bigint *v)
547 #endif
548 {
549 if (v) {
550 ACQUIRE_DTOA_LOCK(0);
551 v->next = freelist[v->k];
552 freelist[v->k] = v;
553 FREE_DTOA_LOCK(0);
554 }
555 }
556
557 #define Bcopy(x,y) memcpy((char *)&x->sign, (char *)&y->sign, \
558 y->wds*sizeof(Long) + 2*sizeof(int))
559
560 static Bigint *
561 multadd
562 #ifdef KR_headers
563 (b, m, a) Bigint *b; int m, a;
564 #else
565 (Bigint *b, int m, int a) /* multiply by m and add a */
566 #endif
567 {
568 int i, wds;
569 #ifdef ULLong
570 ULong *x;
571 ULLong carry, y;
572 #else
573 ULong carry, *x, y;
574 #ifdef Pack_32
575 ULong xi, z;
576 #endif
577 #endif
578 Bigint *b1;
579
580 wds = b->wds;
581 x = b->x;
582 i = 0;
583 carry = a;
584 do {
585 #ifdef ULLong
586 y = *x * (ULLong)m + carry;
587 carry = y >> 32;
588 *x++ = y & FFFFFFFF;
589 #else
590 #ifdef Pack_32
591 xi = *x;
592 y = (xi & 0xffff) * m + carry;
593 z = (xi >> 16) * m + (y >> 16);
594 carry = z >> 16;
595 *x++ = (z << 16) + (y & 0xffff);
596 #else
597 y = *x * m + carry;
598 carry = y >> 16;
599 *x++ = y & 0xffff;
600 #endif
601 #endif
602 }
603 while(++i < wds);
604 if (carry) {
605 if (wds >= b->maxwds) {
606 b1 = Balloc(b->k+1);
607 Bcopy(b1, b);
608 Bfree(b);
609 b = b1;
610 }
611 b->x[wds++] = carry;
612 b->wds = wds;
613 }
614 return b;
615 }
616
617 static Bigint *
618 s2b
619 #ifdef KR_headers
620 (s, nd0, nd, y9) CONST char *s; int nd0, nd; ULong y9;
621 #else
622 (CONST char *s, int nd0, int nd, ULong y9)
623 #endif
624 {
625 Bigint *b;
626 int i, k;
627 Long x, y;
628
629 x = (nd + 8) / 9;
630 for(k = 0, y = 1; x > y; y <<= 1, k++) ;
631 #ifdef Pack_32
632 b = Balloc(k);
633 b->x[0] = y9;
634 b->wds = 1;
635 #else
636 b = Balloc(k+1);
637 b->x[0] = y9 & 0xffff;
638 b->wds = (b->x[1] = y9 >> 16) ? 2 : 1;
639 #endif
640
641 i = 9;
642 if (9 < nd0) {
643 s += 9;
644 do b = multadd(b, 10, *s++ - '0');
645 while(++i < nd0);
646 s++;
647 }
648 else
649 s += 10;
650 for(; i < nd; i++)
651 b = multadd(b, 10, *s++ - '0');
652 return b;
653 }
654
655 static int
656 hi0bits
657 #ifdef KR_headers
658 (x) register ULong x;
659 #else
660 (register ULong x)
661 #endif
662 {
663 register int k = 0;
664
665 if (!(x & 0xffff0000)) {
666 k = 16;
667 x <<= 16;
668 }
669 if (!(x & 0xff000000)) {
670 k += 8;
671 x <<= 8;
672 }
673 if (!(x & 0xf0000000)) {
674 k += 4;
675 x <<= 4;
676 }
677 if (!(x & 0xc0000000)) {
678 k += 2;
679 x <<= 2;
680 }
681 if (!(x & 0x80000000)) {
682 k++;
683 if (!(x & 0x40000000))
684 return 32;
685 }
686 return k;
687 }
688
689 static int
690 lo0bits
691 #ifdef KR_headers
692 (y) ULong *y;
693 #else
694 (ULong *y)
695 #endif
696 {
697 register int k;
698 register ULong x = *y;
699
700 if (x & 7) {
701 if (x & 1)
702 return 0;
703 if (x & 2) {
704 *y = x >> 1;
705 return 1;
706 }
707 *y = x >> 2;
708 return 2;
709 }
710 k = 0;
711 if (!(x & 0xffff)) {
712 k = 16;
713 x >>= 16;
714 }
715 if (!(x & 0xff)) {
716 k += 8;
717 x >>= 8;
718 }
719 if (!(x & 0xf)) {
720 k += 4;
721 x >>= 4;
722 }
723 if (!(x & 0x3)) {
724 k += 2;
725 x >>= 2;
726 }
727 if (!(x & 1)) {
728 k++;
729 x >>= 1;
730 if (!x)
731 return 32;
732 }
733 *y = x;
734 return k;
735 }
736
737 static Bigint *
738 i2b
739 #ifdef KR_headers
740 (i) int i;
741 #else
742 (int i)
743 #endif
744 {
745 Bigint *b;
746
747 b = Balloc(1);
748 b->x[0] = i;
749 b->wds = 1;
750 return b;
751 }
752
753 static Bigint *
754 mult
755 #ifdef KR_headers
756 (a, b) Bigint *a, *b;
757 #else
758 (Bigint *a, Bigint *b)
759 #endif
760 {
761 Bigint *c;
762 int k, wa, wb, wc;
763 ULong *x, *xa, *xae, *xb, *xbe, *xc, *xc0;
764 ULong y;
765 #ifdef ULLong
766 ULLong carry, z;
767 #else
768 ULong carry, z;
769 #ifdef Pack_32
770 ULong z2;
771 #endif
772 #endif
773
774 if (a->wds < b->wds) {
775 c = a;
776 a = b;
777 b = c;
778 }
779 k = a->k;
780 wa = a->wds;
781 wb = b->wds;
782 wc = wa + wb;
783 if (wc > a->maxwds)
784 k++;
785 c = Balloc(k);
786 for(x = c->x, xa = x + wc; x < xa; x++)
787 *x = 0;
788 xa = a->x;
789 xae = xa + wa;
790 xb = b->x;
791 xbe = xb + wb;
792 xc0 = c->x;
793 #ifdef ULLong
794 for(; xb < xbe; xc0++) {
795 if (y = *xb++) {
796 x = xa;
797 xc = xc0;
798 carry = 0;
799 do {
800 z = *x++ * (ULLong)y + *xc + carry;
801 carry = z >> 32;
802 *xc++ = z & FFFFFFFF;
803 }
804 while(x < xae);
805 *xc = carry;
806 }
807 }
808 #else
809 #ifdef Pack_32
810 for(; xb < xbe; xb++, xc0++) {
811 if (y = *xb & 0xffff) {
812 x = xa;
813 xc = xc0;
814 carry = 0;
815 do {
816 z = (*x & 0xffff) * y + (*xc & 0xffff) + carry;
817 carry = z >> 16;
818 z2 = (*x++ >> 16) * y + (*xc >> 16) + carry;
819 carry = z2 >> 16;
820 Storeinc(xc, z2, z);
821 }
822 while(x < xae);
823 *xc = carry;
824 }
825 if (y = *xb >> 16) {
826 x = xa;
827 xc = xc0;
828 carry = 0;
829 z2 = *xc;
830 do {
831 z = (*x & 0xffff) * y + (*xc >> 16) + carry;
832 carry = z >> 16;
833 Storeinc(xc, z, z2);
834 z2 = (*x++ >> 16) * y + (*xc & 0xffff) + carry;
835 carry = z2 >> 16;
836 }
837 while(x < xae);
838 *xc = z2;
839 }
840 }
841 #else
842 for(; xb < xbe; xc0++) {
843 if (y = *xb++) {
844 x = xa;
845 xc = xc0;
846 carry = 0;
847 do {
848 z = *x++ * y + *xc + carry;
849 carry = z >> 16;
850 *xc++ = z & 0xffff;
851 }
852 while(x < xae);
853 *xc = carry;
854 }
855 }
856 #endif
857 #endif
858 for(xc0 = c->x, xc = xc0 + wc; wc > 0 && !*--xc; --wc) ;
859 c->wds = wc;
860 return c;
861 }
862
863 static Bigint *p5s;
864
865 static Bigint *
866 pow5mult
867 #ifdef KR_headers
868 (b, k) Bigint *b; int k;
869 #else
870 (Bigint *b, int k)
871 #endif
872 {
873 Bigint *b1, *p5, *p51;
874 int i;
875 static int p05[3] = { 5, 25, 125 };
876
877 if (i = k & 3)
878 b = multadd(b, p05[i-1], 0);
879
880 if (!(k >>= 2))
881 return b;
882 if (!(p5 = p5s)) {
883 /* first time */
884 #ifdef MULTIPLE_THREADS
885 ACQUIRE_DTOA_LOCK(1);
886 if (!(p5 = p5s)) {
887 p5 = p5s = i2b(625);
888 p5->next = 0;
889 }
890 FREE_DTOA_LOCK(1);
891 #else
892 p5 = p5s = i2b(625);
893 p5->next = 0;
894 #endif
895 }
896 for(;;) {
897 if (k & 1) {
898 b1 = mult(b, p5);
899 Bfree(b);
900 b = b1;
901 }
902 if (!(k >>= 1))
903 break;
904 if (!(p51 = p5->next)) {
905 #ifdef MULTIPLE_THREADS
906 ACQUIRE_DTOA_LOCK(1);
907 if (!(p51 = p5->next)) {
908 p51 = p5->next = mult(p5,p5);
909 p51->next = 0;
910 }
911 FREE_DTOA_LOCK(1);
912 #else
913 p51 = p5->next = mult(p5,p5);
914 p51->next = 0;
915 #endif
916 }
917 p5 = p51;
918 }
919 return b;
920 }
921
922 static Bigint *
923 lshift
924 #ifdef KR_headers
925 (b, k) Bigint *b; int k;
926 #else
927 (Bigint *b, int k)
928 #endif
929 {
930 int i, k1, n, n1;
931 Bigint *b1;
932 ULong *x, *x1, *xe, z;
933
934 #ifdef Pack_32
935 n = k >> 5;
936 #else
937 n = k >> 4;
938 #endif
939 k1 = b->k;
940 n1 = n + b->wds + 1;
941 for(i = b->maxwds; n1 > i; i <<= 1)
942 k1++;
943 b1 = Balloc(k1);
944 x1 = b1->x;
945 for(i = 0; i < n; i++)
946 *x1++ = 0;
947 x = b->x;
948 xe = x + b->wds;
949 #ifdef Pack_32
950 if (k &= 0x1f) {
951 k1 = 32 - k;
952 z = 0;
953 do {
954 *x1++ = *x << k | z;
955 z = *x++ >> k1;
956 }
957 while(x < xe);
958 if (*x1 = z)
959 ++n1;
960 }
961 #else
962 if (k &= 0xf) {
963 k1 = 16 - k;
964 z = 0;
965 do {
966 *x1++ = *x << k & 0xffff | z;
967 z = *x++ >> k1;
968 }
969 while(x < xe);
970 if (*x1 = z)
971 ++n1;
972 }
973 #endif
974 else do
975 *x1++ = *x++;
976 while(x < xe);
977 b1->wds = n1 - 1;
978 Bfree(b);
979 return b1;
980 }
981
982 static int
983 cmp
984 #ifdef KR_headers
985 (a, b) Bigint *a, *b;
986 #else
987 (Bigint *a, Bigint *b)
988 #endif
989 {
990 ULong *xa, *xa0, *xb, *xb0;
991 int i, j;
992
993 i = a->wds;
994 j = b->wds;
995 #ifdef DEBUG
996 if (i > 1 && !a->x[i-1])
997 Bug("cmp called with a->x[a->wds-1] == 0");
998 if (j > 1 && !b->x[j-1])
999 Bug("cmp called with b->x[b->wds-1] == 0");
1000 #endif
1001 if (i -= j)
1002 return i;
1003 xa0 = a->x;
1004 xa = xa0 + j;
1005 xb0 = b->x;
1006 xb = xb0 + j;
1007 for(;;) {
1008 if (*--xa != *--xb)
1009 return *xa < *xb ? -1 : 1;
1010 if (xa <= xa0)
1011 break;
1012 }
1013 return 0;
1014 }
1015
1016 static Bigint *
1017 diff
1018 #ifdef KR_headers
1019 (a, b) Bigint *a, *b;
1020 #else
1021 (Bigint *a, Bigint *b)
1022 #endif
1023 {
1024 Bigint *c;
1025 int i, wa, wb;
1026 ULong *xa, *xae, *xb, *xbe, *xc;
1027 #ifdef ULLong
1028 ULLong borrow, y;
1029 #else
1030 ULong borrow, y;
1031 #ifdef Pack_32
1032 ULong z;
1033 #endif
1034 #endif
1035
1036 i = cmp(a,b);
1037 if (!i) {
1038 c = Balloc(0);
1039 c->wds = 1;
1040 c->x[0] = 0;
1041 return c;
1042 }
1043 if (i < 0) {
1044 c = a;
1045 a = b;
1046 b = c;
1047 i = 1;
1048 }
1049 else
1050 i = 0;
1051 c = Balloc(a->k);
1052 c->sign = i;
1053 wa = a->wds;
1054 xa = a->x;
1055 xae = xa + wa;
1056 wb = b->wds;
1057 xb = b->x;
1058 xbe = xb + wb;
1059 xc = c->x;
1060 borrow = 0;
1061 #ifdef ULLong
1062 do {
1063 y = (ULLong)*xa++ - *xb++ - borrow;
1064 borrow = y >> 32 & (ULong)1;
1065 *xc++ = y & FFFFFFFF;
1066 }
1067 while(xb < xbe);
1068 while(xa < xae) {
1069 y = *xa++ - borrow;
1070 borrow = y >> 32 & (ULong)1;
1071 *xc++ = y & FFFFFFFF;
1072 }
1073 #else
1074 #ifdef Pack_32
1075 do {
1076 y = (*xa & 0xffff) - (*xb & 0xffff) - borrow;
1077 borrow = (y & 0x10000) >> 16;
1078 z = (*xa++ >> 16) - (*xb++ >> 16) - borrow;
1079 borrow = (z & 0x10000) >> 16;
1080 Storeinc(xc, z, y);
1081 }
1082 while(xb < xbe);
1083 while(xa < xae) {
1084 y = (*xa & 0xffff) - borrow;
1085 borrow = (y & 0x10000) >> 16;
1086 z = (*xa++ >> 16) - borrow;
1087 borrow = (z & 0x10000) >> 16;
1088 Storeinc(xc, z, y);
1089 }
1090 #else
1091 do {
1092 y = *xa++ - *xb++ - borrow;
1093 borrow = (y & 0x10000) >> 16;
1094 *xc++ = y & 0xffff;
1095 }
1096 while(xb < xbe);
1097 while(xa < xae) {
1098 y = *xa++ - borrow;
1099 borrow = (y & 0x10000) >> 16;
1100 *xc++ = y & 0xffff;
1101 }
1102 #endif
1103 #endif
1104 while(!*--xc)
1105 wa--;
1106 c->wds = wa;
1107 return c;
1108 }
1109
1110 static double
1111 ulp
1112 #ifdef KR_headers
1113 (x) double x;
1114 #else
1115 (double x)
1116 #endif
1117 {
1118 register Long L;
1119 double a;
1120
1121 L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1;
1122 #ifndef Avoid_Underflow
1123 #ifndef Sudden_Underflow
1124 if (L > 0) {
1125 #endif
1126 #endif
1127 #ifdef IBM
1128 L |= Exp_msk1 >> 4;
1129 #endif
1130 word0(a) = L;
1131 word1(a) = 0;
1132 #ifndef Avoid_Underflow
1133 #ifndef Sudden_Underflow
1134 }
1135 else {
1136 L = -L >> Exp_shift;
1137 if (L < Exp_shift) {
1138 word0(a) = 0x80000 >> L;
1139 word1(a) = 0;
1140 }
1141 else {
1142 word0(a) = 0;
1143 L -= Exp_shift;
1144 word1(a) = L >= 31 ? 1 : 1 << 31 - L;
1145 }
1146 }
1147 #endif
1148 #endif
1149 return dval(a);
1150 }
1151
1152 static double
1153 b2d
1154 #ifdef KR_headers
1155 (a, e) Bigint *a; int *e;
1156 #else
1157 (Bigint *a, int *e)
1158 #endif
1159 {
1160 ULong *xa, *xa0, w, y, z;
1161 int k;
1162 double d;
1163 #ifdef VAX
1164 ULong d0, d1;
1165 #else
1166 #define d0 word0(d)
1167 #define d1 word1(d)
1168 #endif
1169
1170 xa0 = a->x;
1171 xa = xa0 + a->wds;
1172 y = *--xa;
1173 #ifdef DEBUG
1174 if (!y) Bug("zero y in b2d");
1175 #endif
1176 k = hi0bits(y);
1177 *e = 32 - k;
1178 #ifdef Pack_32
1179 if (k < Ebits) {
1180 d0 = Exp_1 | y >> Ebits - k;
1181 w = xa > xa0 ? *--xa : 0;
1182 d1 = y << (32-Ebits) + k | w >> Ebits - k;
1183 goto ret_d;
1184 }
1185 z = xa > xa0 ? *--xa : 0;
1186 if (k -= Ebits) {
1187 d0 = Exp_1 | y << k | z >> 32 - k;
1188 y = xa > xa0 ? *--xa : 0;
1189 d1 = z << k | y >> 32 - k;
1190 }
1191 else {
1192 d0 = Exp_1 | y;
1193 d1 = z;
1194 }
1195 #else
1196 if (k < Ebits + 16) {
1197 z = xa > xa0 ? *--xa : 0;
1198 d0 = Exp_1 | y << k - Ebits | z >> Ebits + 16 - k;
1199 w = xa > xa0 ? *--xa : 0;
1200 y = xa > xa0 ? *--xa : 0;
1201 d1 = z << k + 16 - Ebits | w << k - Ebits | y >> 16 + Ebits - k;
1202 goto ret_d;
1203 }
1204 z = xa > xa0 ? *--xa : 0;
1205 w = xa > xa0 ? *--xa : 0;
1206 k -= Ebits + 16;
1207 d0 = Exp_1 | y << k + 16 | z << k | w >> 16 - k;
1208 y = xa > xa0 ? *--xa : 0;
1209 d1 = w << k + 16 | y << k;
1210 #endif
1211 ret_d:
1212 #ifdef VAX
1213 word0(d) = d0 >> 16 | d0 << 16;
1214 word1(d) = d1 >> 16 | d1 << 16;
1215 #else
1216 #undef d0
1217 #undef d1
1218 #endif
1219 return dval(d);
1220 }
1221
1222 static Bigint *
1223 d2b
1224 #ifdef KR_headers
1225 (d, e, bits) double d; int *e, *bits;
1226 #else
1227 (double d, int *e, int *bits)
1228 #endif
1229 {
1230 Bigint *b;
1231 int de, k;
1232 ULong *x, y, z;
1233 #ifndef Sudden_Underflow
1234 int i;
1235 #endif
1236 #ifdef VAX
1237 ULong d0, d1;
1238 d0 = word0(d) >> 16 | word0(d) << 16;
1239 d1 = word1(d) >> 16 | word1(d) << 16;
1240 #else
1241 #define d0 word0(d)
1242 #define d1 word1(d)
1243 #endif
1244
1245 #ifdef Pack_32
1246 b = Balloc(1);
1247 #else
1248 b = Balloc(2);
1249 #endif
1250 x = b->x;
1251
1252 z = d0 & Frac_mask;
1253 d0 &= 0x7fffffff; /* clear sign bit, which we ignore */
1254 #ifdef Sudden_Underflow
1255 de = (int)(d0 >> Exp_shift);
1256 #ifndef IBM
1257 z |= Exp_msk11;
1258 #endif
1259 #else
1260 if (de = (int)(d0 >> Exp_shift))
1261 z |= Exp_msk1;
1262 #endif
1263 #ifdef Pack_32
1264 if (y = d1) {
1265 if (k = lo0bits(&y)) {
1266 x[0] = y | z << 32 - k;
1267 z >>= k;
1268 }
1269 else
1270 x[0] = y;
1271 #ifndef Sudden_Underflow
1272 i =
1273 #endif
1274 b->wds = (x[1] = z) ? 2 : 1;
1275 }
1276 else {
1277 #ifdef DEBUG
1278 if (!z)
1279 Bug("Zero passed to d2b");
1280 #endif
1281 k = lo0bits(&z);
1282 x[0] = z;
1283 #ifndef Sudden_Underflow
1284 i =
1285 #endif
1286 b->wds = 1;
1287 k += 32;
1288 }
1289 #else
1290 if (y = d1) {
1291 if (k = lo0bits(&y))
1292 if (k >= 16) {
1293 x[0] = y | z << 32 - k & 0xffff;
1294 x[1] = z >> k - 16 & 0xffff;
1295 x[2] = z >> k;
1296 i = 2;
1297 }
1298 else {
1299 x[0] = y & 0xffff;
1300 x[1] = y >> 16 | z << 16 - k & 0xffff;
1301 x[2] = z >> k & 0xffff;
1302 x[3] = z >> k+16;
1303 i = 3;
1304 }
1305 else {
1306 x[0] = y & 0xffff;
1307 x[1] = y >> 16;
1308 x[2] = z & 0xffff;
1309 x[3] = z >> 16;
1310 i = 3;
1311 }
1312 }
1313 else {
1314 #ifdef DEBUG
1315 if (!z)
1316 Bug("Zero passed to d2b");
1317 #endif
1318 k = lo0bits(&z);
1319 if (k >= 16) {
1320 x[0] = z;
1321 i = 0;
1322 }
1323 else {
1324 x[0] = z & 0xffff;
1325 x[1] = z >> 16;
1326 i = 1;
1327 }
1328 k += 32;
1329 }
1330 while(!x[i])
1331 --i;
1332 b->wds = i + 1;
1333 #endif
1334 #ifndef Sudden_Underflow
1335 if (de) {
1336 #endif
1337 #ifdef IBM
1338 *e = (de - Bias - (P-1) << 2) + k;
1339 *bits = 4*P + 8 - k - hi0bits(word0(d) & Frac_mask);
1340 #else
1341 *e = de - Bias - (P-1) + k;
1342 *bits = P - k;
1343 #endif
1344 #ifndef Sudden_Underflow
1345 }
1346 else {
1347 *e = de - Bias - (P-1) + 1 + k;
1348 #ifdef Pack_32
1349 *bits = 32*i - hi0bits(x[i-1]);
1350 #else
1351 *bits = (i+2)*16 - hi0bits(x[i]);
1352 #endif
1353 }
1354 #endif
1355 return b;
1356 }
1357 #undef d0
1358 #undef d1
1359
1360 static double
1361 ratio
1362 #ifdef KR_headers
1363 (a, b) Bigint *a, *b;
1364 #else
1365 (Bigint *a, Bigint *b)
1366 #endif
1367 {
1368 double da, db;
1369 int k, ka, kb;
1370
1371 dval(da) = b2d(a, &ka);
1372 dval(db) = b2d(b, &kb);
1373 #ifdef Pack_32
1374 k = ka - kb + 32*(a->wds - b->wds);
1375 #else
1376 k = ka - kb + 16*(a->wds - b->wds);
1377 #endif
1378 #ifdef IBM
1379 if (k > 0) {
1380 word0(da) += (k >> 2)*Exp_msk1;
1381 if (k &= 3)
1382 dval(da) *= 1 << k;
1383 }
1384 else {
1385 k = -k;
1386 word0(db) += (k >> 2)*Exp_msk1;
1387 if (k &= 3)
1388 dval(db) *= 1 << k;
1389 }
1390 #else
1391 if (k > 0)
1392 word0(da) += k*Exp_msk1;
1393 else {
1394 k = -k;
1395 word0(db) += k*Exp_msk1;
1396 }
1397 #endif
1398 return dval(da) / dval(db);
1399 }
1400
1401 static CONST double
1402 tens[] = {
1403 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
1404 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
1405 1e20, 1e21, 1e22
1406 #ifdef VAX
1407 , 1e23, 1e24
1408 #endif
1409 };
1410
1411 static CONST double
1412 #ifdef IEEE_Arith
1413 bigtens[] = { 1e16, 1e32, 1e64, 1e128, 1e256 };
1414 static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128,
1415 #ifdef Avoid_Underflow
1416 9007199254740992.*9007199254740992.e-256
1417 /* = 2^106 * 1e-256 */
1418 #else
1419 1e-256
1420 #endif
1421 };
1422 /* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */
1423 /* flag unnecessarily. It leads to a song and dance at the end of strtod. */
1424 #define Scale_Bit 0x10
1425 #define n_bigtens 5
1426 #else
1427 #ifdef IBM
1428 bigtens[] = { 1e16, 1e32, 1e64 };
1429 static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64 };
1430 #define n_bigtens 3
1431 #else
1432 bigtens[] = { 1e16, 1e32 };
1433 static CONST double tinytens[] = { 1e-16, 1e-32 };
1434 #define n_bigtens 2
1435 #endif
1436 #endif
1437
1438 #ifdef INFNAN_CHECK
1439
1440 #ifndef NAN_WORD0
1441 #define NAN_WORD0 0x7ff80000
1442 #endif
1443
1444 #ifndef NAN_WORD1
1445 #define NAN_WORD1 0
1446 #endif
1447
1448 static int
1449 match
1450 #ifdef KR_headers
1451 (sp, t) char **sp, *t;
1452 #else
1453 (CONST char **sp, char *t)
1454 #endif
1455 {
1456 int c, d;
1457 CONST char *s = *sp;
1458
1459 while(d = *t++) {
1460 if ((c = *++s) >= 'A' && c <= 'Z')
1461 c += 'a' - 'A';
1462 if (c != d)
1463 return 0;
1464 }
1465 *sp = s + 1;
1466 return 1;
1467 }
1468
1469 #ifndef No_Hex_NaN
1470 static void
1471 hexnan
1472 #ifdef KR_headers
1473 (rvp, sp) double *rvp; CONST char **sp;
1474 #else
1475 (double *rvp, CONST char **sp)
1476 #endif
1477 {
1478 ULong c, x[2];
1479 CONST char *s;
1480 int havedig, udx0, xshift;
1481
1482 x[0] = x[1] = 0;
1483 havedig = xshift = 0;
1484 udx0 = 1;
1485 s = *sp;
1486 /* allow optional initial 0x or 0X */
1487 while((c = *(CONST unsigned char*)(s+1)) && c <= ' ')
1488 ++s;
1489 if (s[1] == '0' && (s[2] == 'x' || s[2] == 'X'))
1490 s += 2;
1491 while(c = *(CONST unsigned char*)++s) {
1492 if (c >= '0' && c <= '9')
1493 c -= '0';
1494 else if (c >= 'a' && c <= 'f')
1495 c += 10 - 'a';
1496 else if (c >= 'A' && c <= 'F')
1497 c += 10 - 'A';
1498 else if (c <= ' ') {
1499 if (udx0 && havedig) {
1500 udx0 = 0;
1501 xshift = 1;
1502 }
1503 continue;
1504 }
1505 #ifdef GDTOA_NON_PEDANTIC_NANCHECK
1506 else if (/*(*/ c == ')' && havedig) {
1507 *sp = s + 1;
1508 break;
1509 }
1510 else
1511 return; /* invalid form: don't change *sp */
1512 #else
1513 else {
1514 do {
1515 if (/*(*/ c == ')') {
1516 *sp = s + 1;
1517 break;
1518 }
1519 } while(c = *++s);
1520 break;
1521 }
1522 #endif
1523 havedig = 1;
1524 if (xshift) {
1525 xshift = 0;
1526 x[0] = x[1];
1527 x[1] = 0;
1528 }
1529 if (udx0)
1530 x[0] = (x[0] << 4) | (x[1] >> 28);
1531 x[1] = (x[1] << 4) | c;
1532 }
1533 if ((x[0] &= 0xfffff) || x[1]) {
1534 word0(*rvp) = Exp_mask | x[0];
1535 word1(*rvp) = x[1];
1536 }
1537 }
1538 #endif /*No_Hex_NaN*/
1539 #endif /* INFNAN_CHECK */
1540
1541 double
1542 strtod
1543 #ifdef KR_headers
1544 (s00, se) CONST char *s00; char **se;
1545 #else
1546 (CONST char *s00, char **se)
1547 #endif
1548 {
1549 #ifdef Avoid_Underflow
1550 int scale;
1551 #endif
1552 int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, dsign,
1553 e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign;
1554 CONST char *s, *s0, *s1;
1555 double aadj, aadj1, adj, rv, rv0;
1556 Long L;
1557 ULong y, z;
1558 Bigint *bb, *bb1, *bd, *bd0, *bs, *delta;
1559 #ifdef SET_INEXACT
1560 int inexact, oldinexact;
1561 #endif
1562 #ifdef Honor_FLT_ROUNDS /*{*/
1563 int Rounding;
1564 #ifdef Trust_FLT_ROUNDS /*{{ only define this if FLT_ROUNDS really works! */
1565 Rounding = Flt_Rounds;
1566 #else /*}{*/
1567 Rounding = 1;
1568 switch(fegetround()) {
1569 case FE_TOWARDZERO: Rounding = 0; break;
1570 case FE_UPWARD: Rounding = 2; break;
1571 case FE_DOWNWARD: Rounding = 3;
1572 }
1573 #endif /*}}*/
1574 #endif /*}*/
1575 #ifdef USE_LOCALE
1576 CONST char *s2;
1577 #endif
1578
1579 sign = nz0 = nz = 0;
1580 dval(rv) = 0.;
1581 for(s = s00;;s++) switch(*s) {
1582 case '-':
1583 sign = 1;
1584 /* no break */
1585 case '+':
1586 if (*++s)
1587 goto break2;
1588 /* no break */
1589 case 0:
1590 goto ret0;
1591 case '\t':
1592 case '\n':
1593 case '\v':
1594 case '\f':
1595 case '\r':
1596 case ' ':
1597 continue;
1598 default:
1599 goto break2;
1600 }
1601 break2:
1602 if (*s == '0') {
1603 nz0 = 1;
1604 while(*++s == '0') ;
1605 if (!*s)
1606 goto ret;
1607 }
1608 s0 = s;
1609 y = z = 0;
1610 for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)
1611 if (nd < 9)
1612 y = 10*y + c - '0';
1613 else if (nd < 16)
1614 z = 10*z + c - '0';
1615 nd0 = nd;
1616 #ifdef USE_LOCALE
1617 s1 = localeconv()->decimal_point;
1618 if (c == *s1) {
1619 c = '.';
1620 if (*++s1) {
1621 s2 = s;
1622 for(;;) {
1623 if (*++s2 != *s1) {
1624 c = 0;
1625 break;
1626 }
1627 if (!*++s1) {
1628 s = s2;
1629 break;
1630 }
1631 }
1632 }
1633 }
1634 #endif
1635 if (c == '.') {
1636 c = *++s;
1637 if (!nd) {
1638 for(; c == '0'; c = *++s)
1639 nz++;
1640 if (c > '0' && c <= '9') {
1641 s0 = s;
1642 nf += nz;
1643 nz = 0;
1644 goto have_dig;
1645 }
1646 goto dig_done;
1647 }
1648 for(; c >= '0' && c <= '9'; c = *++s) {
1649 have_dig:
1650 nz++;
1651 if (c -= '0') {
1652 nf += nz;
1653 for(i = 1; i < nz; i++)
1654 if (nd++ < 9)
1655 y *= 10;
1656 else if (nd <= DBL_DIG + 1)
1657 z *= 10;
1658 if (nd++ < 9)
1659 y = 10*y + c;
1660 else if (nd <= DBL_DIG + 1)
1661 z = 10*z + c;
1662 nz = 0;
1663 }
1664 }
1665 }
1666 dig_done:
1667 e = 0;
1668 if (c == 'e' || c == 'E') {
1669 if (!nd && !nz && !nz0) {
1670 goto ret0;
1671 }
1672 s00 = s;
1673 esign = 0;
1674 switch(c = *++s) {
1675 case '-':
1676 esign = 1;
1677 case '+':
1678 c = *++s;
1679 }
1680 if (c >= '0' && c <= '9') {
1681 while(c == '0')
1682 c = *++s;
1683 if (c > '0' && c <= '9') {
1684 L = c - '0';
1685 s1 = s;
1686 while((c = *++s) >= '0' && c <= '9')
1687 L = 10*L + c - '0';
1688 if (s - s1 > 8 || L > 19999)
1689 /* Avoid confusion from exponents
1690 * so large that e might overflow.
1691 */
1692 e = 19999; /* safe for 16 bit ints */
1693 else
1694 e = (int)L;
1695 if (esign)
1696 e = -e;
1697 }
1698 else
1699 e = 0;
1700 }
1701 else
1702 s = s00;
1703 }
1704 if (!nd) {
1705 if (!nz && !nz0) {
1706 #ifdef INFNAN_CHECK
1707 /* Check for Nan and Infinity */
1708 switch(c) {
1709 case 'i':
1710 case 'I':
1711 if (match(&s,"nf")) {
1712 --s;
1713 if (!match(&s,"inity"))
1714 ++s;
1715 word0(rv) = 0x7ff00000;
1716 word1(rv) = 0;
1717 goto ret;
1718 }
1719 break;
1720 case 'n':
1721 case 'N':
1722 if (match(&s, "an")) {
1723 word0(rv) = NAN_WORD0;
1724 word1(rv) = NAN_WORD1;
1725 #ifndef No_Hex_NaN
1726 if (*s == '(') /*)*/
1727 hexnan(&rv, &s);
1728 #endif
1729 goto ret;
1730 }
1731 }
1732 #endif /* INFNAN_CHECK */
1733 ret0:
1734 s = s00;
1735 sign = 0;
1736 }
1737 goto ret;
1738 }
1739 e1 = e -= nf;
1740
1741 /* Now we have nd0 digits, starting at s0, followed by a
1742 * decimal point, followed by nd-nd0 digits. The number we're
1743 * after is the integer represented by those digits times
1744 * 10**e */
1745
1746 if (!nd0)
1747 nd0 = nd;
1748 k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;
1749 dval(rv) = y;
1750 if (k > 9) {
1751 #ifdef SET_INEXACT
1752 if (k > DBL_DIG)
1753 oldinexact = get_inexact();
1754 #endif
1755 dval(rv) = tens[k - 9] * dval(rv) + z;
1756 }
1757 bd0 = 0;
1758 if (nd <= DBL_DIG
1759 #ifndef RND_PRODQUOT
1760 #ifndef Honor_FLT_ROUNDS
1761 && Flt_Rounds == 1
1762 #endif
1763 #endif
1764 ) {
1765 if (!e)
1766 goto ret;
1767 if (e > 0) {
1768 if (e <= Ten_pmax) {
1769 #ifdef VAX
1770 goto vax_ovfl_check;
1771 #else
1772 #ifdef Honor_FLT_ROUNDS
1773 /* round correctly FLT_ROUNDS = 2 or 3 */
1774 if (sign) {
1775 rv = -rv;
1776 sign = 0;
1777 }
1778 #endif
1779 /* rv = */ rounded_product(dval(rv), tens[e]);
1780 goto ret;
1781 #endif
1782 }
1783 i = DBL_DIG - nd;
1784 if (e <= Ten_pmax + i) {
1785 /* A fancier test would sometimes let us do
1786 * this for larger i values.
1787 */
1788 #ifdef Honor_FLT_ROUNDS
1789 /* round correctly FLT_ROUNDS = 2 or 3 */
1790 if (sign) {
1791 rv = -rv;
1792 sign = 0;
1793 }
1794 #endif
1795 e -= i;
1796 dval(rv) *= tens[i];
1797 #ifdef VAX
1798 /* VAX exponent range is so narrow we must
1799 * worry about overflow here...
1800 */
1801 vax_ovfl_check:
1802 word0(rv) -= P*Exp_msk1;
1803 /* rv = */ rounded_product(dval(rv), tens[e]);
1804 if ((word0(rv) & Exp_mask)
1805 > Exp_msk1*(DBL_MAX_EXP+Bias-1-P))
1806 goto ovfl;
1807 word0(rv) += P*Exp_msk1;
1808 #else
1809 /* rv = */ rounded_product(dval(rv), tens[e]);
1810 #endif
1811 goto ret;
1812 }
1813 }
1814 #ifndef Inaccurate_Divide
1815 else if (e >= -Ten_pmax) {
1816 #ifdef Honor_FLT_ROUNDS
1817 /* round correctly FLT_ROUNDS = 2 or 3 */
1818 if (sign) {
1819 rv = -rv;
1820 sign = 0;
1821 }
1822 #endif
1823 /* rv = */ rounded_quotient(dval(rv), tens[-e]);
1824 goto ret;
1825 }
1826 #endif
1827 }
1828 e1 += nd - k;
1829
1830 #ifdef IEEE_Arith
1831 #ifdef SET_INEXACT
1832 inexact = 1;
1833 if (k <= DBL_DIG)
1834 oldinexact = get_inexact();
1835 #endif
1836 #ifdef Avoid_Underflow
1837 scale = 0;
1838 #endif
1839 #ifdef Honor_FLT_ROUNDS
1840 if (Rounding >= 2) {
1841 if (sign)
1842 Rounding = Rounding == 2 ? 0 : 2;
1843 else
1844 if (Rounding != 2)
1845 Rounding = 0;
1846 }
1847 #endif
1848 #endif /*IEEE_Arith*/
1849
1850 /* Get starting approximation = rv * 10**e1 */
1851
1852 if (e1 > 0) {
1853 if (i = e1 & 15)
1854 dval(rv) *= tens[i];
1855 if (e1 &= ~15) {
1856 if (e1 > DBL_MAX_10_EXP) {
1857 ovfl:
1858 #ifndef NO_ERRNO
1859 errno = ERANGE;
1860 #endif
1861 /* Can't trust HUGE_VAL */
1862 #ifdef IEEE_Arith
1863 #ifdef Honor_FLT_ROUNDS
1864 switch(Rounding) {
1865 case 0: /* toward 0 */
1866 case 3: /* toward -infinity */
1867 word0(rv) = Big0;
1868 word1(rv) = Big1;
1869 break;
1870 default:
1871 word0(rv) = Exp_mask;
1872 word1(rv) = 0;
1873 }
1874 #else /*Honor_FLT_ROUNDS*/
1875 word0(rv) = Exp_mask;
1876 word1(rv) = 0;
1877 #endif /*Honor_FLT_ROUNDS*/
1878 #ifdef SET_INEXACT
1879 /* set overflow bit */
1880 dval(rv0) = 1e300;
1881 dval(rv0) *= dval(rv0);
1882 #endif
1883 #else /*IEEE_Arith*/
1884 word0(rv) = Big0;
1885 word1(rv) = Big1;
1886 #endif /*IEEE_Arith*/
1887 if (bd0)
1888 goto retfree;
1889 goto ret;
1890 }
1891 e1 >>= 4;
1892 for(j = 0; e1 > 1; j++, e1 >>= 1)
1893 if (e1 & 1)
1894 dval(rv) *= bigtens[j];
1895 /* The last multiplication could overflow. */
1896 word0(rv) -= P*Exp_msk1;
1897 dval(rv) *= bigtens[j];
1898 if ((z = word0(rv) & Exp_mask)
1899 > Exp_msk1*(DBL_MAX_EXP+Bias-P))
1900 goto ovfl;
1901 if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) {
1902 /* set to largest number */
1903 /* (Can't trust DBL_MAX) */
1904 word0(rv) = Big0;
1905 word1(rv) = Big1;
1906 }
1907 else
1908 word0(rv) += P*Exp_msk1;
1909 }
1910 }
1911 else if (e1 < 0) {
1912 e1 = -e1;
1913 if (i = e1 & 15)
1914 dval(rv) /= tens[i];
1915 if (e1 >>= 4) {
1916 if (e1 >= 1 << n_bigtens)
1917 goto undfl;
1918 #ifdef Avoid_Underflow
1919 if (e1 & Scale_Bit)
1920 scale = 2*P;
1921 for(j = 0; e1 > 0; j++, e1 >>= 1)
1922 if (e1 & 1)
1923 dval(rv) *= tinytens[j];
1924 if (scale && (j = 2*P + 1 - ((word0(rv) & Exp_mask)
1925 >> Exp_shift)) > 0) {
1926 /* scaled rv is denormal; clear j low bits */
1927 if (j >= 32) {
1928 word1(rv) = 0;
1929 if (j >= 53)
1930 word0(rv) = (P+2)*Exp_msk1;
1931 else
1932 word0(rv) &= 0xffffffff << j-32;
1933 }
1934 else
1935 word1(rv) &= 0xffffffff << j;
1936 }
1937 #else
1938 for(j = 0; e1 > 1; j++, e1 >>= 1)
1939 if (e1 & 1)
1940 dval(rv) *= tinytens[j];
1941 /* The last multiplication could underflow. */
1942 dval(rv0) = dval(rv);
1943 dval(rv) *= tinytens[j];
1944 if (!dval(rv)) {
1945 dval(rv) = 2.*dval(rv0);
1946 dval(rv) *= tinytens[j];
1947 #endif
1948 if (!dval(rv)) {
1949 undfl:
1950 dval(rv) = 0.;
1951 #ifndef NO_ERRNO
1952 errno = ERANGE;
1953 #endif
1954 if (bd0)
1955 goto retfree;
1956 goto ret;
1957 }
1958 #ifndef Avoid_Underflow
1959 word0(rv) = Tiny0;
1960 word1(rv) = Tiny1;
1961 /* The refinement below will clean
1962 * this approximation up.
1963 */
1964 }
1965 #endif
1966 }
1967 }
1968
1969 /* Now the hard part -- adjusting rv to the correct value.*/
1970
1971 /* Put digits into bd: true value = bd * 10^e */
1972
1973 bd0 = s2b(s0, nd0, nd, y);
1974
1975 for(;;) {
1976 bd = Balloc(bd0->k);
1977 Bcopy(bd, bd0);
1978 bb = d2b(dval(rv), &bbe, &bbbits); /* rv = bb * 2^bbe */
1979 bs = i2b(1);
1980
1981 if (e >= 0) {
1982 bb2 = bb5 = 0;
1983 bd2 = bd5 = e;
1984 }
1985 else {
1986 bb2 = bb5 = -e;
1987 bd2 = bd5 = 0;
1988 }
1989 if (bbe >= 0)
1990 bb2 += bbe;
1991 else
1992 bd2 -= bbe;
1993 bs2 = bb2;
1994 #ifdef Honor_FLT_ROUNDS
1995 if (Rounding != 1)
1996 bs2++;
1997 #endif
1998 #ifdef Avoid_Underflow
1999 j = bbe - scale;
2000 i = j + bbbits - 1; /* logb(rv) */
2001 if (i < Emin) /* denormal */
2002 j += P - Emin;
2003 else
2004 j = P + 1 - bbbits;
2005 #else /*Avoid_Underflow*/
2006 #ifdef Sudden_Underflow
2007 #ifdef IBM
2008 j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3);
2009 #else
2010 j = P + 1 - bbbits;
2011 #endif
2012 #else /*Sudden_Underflow*/
2013 j = bbe;
2014 i = j + bbbits - 1; /* logb(rv) */
2015 if (i < Emin) /* denormal */
2016 j += P - Emin;
2017 else
2018 j = P + 1 - bbbits;
2019 #endif /*Sudden_Underflow*/
2020 #endif /*Avoid_Underflow*/
2021 bb2 += j;
2022 bd2 += j;
2023 #ifdef Avoid_Underflow
2024 bd2 += scale;
2025 #endif
2026 i = bb2 < bd2 ? bb2 : bd2;
2027 if (i > bs2)
2028 i = bs2;
2029 if (i > 0) {
2030 bb2 -= i;
2031 bd2 -= i;
2032 bs2 -= i;
2033 }
2034 if (bb5 > 0) {
2035 bs = pow5mult(bs, bb5);
2036 bb1 = mult(bs, bb);
2037 Bfree(bb);
2038 bb = bb1;
2039 }
2040 if (bb2 > 0)
2041 bb = lshift(bb, bb2);
2042 if (bd5 > 0)
2043 bd = pow5mult(bd, bd5);
2044 if (bd2 > 0)
2045 bd = lshift(bd, bd2);
2046 if (bs2 > 0)
2047 bs = lshift(bs, bs2);
2048 delta = diff(bb, bd);
2049 dsign = delta->sign;
2050 delta->sign = 0;
2051 i = cmp(delta, bs);
2052 #ifdef Honor_FLT_ROUNDS
2053 if (Rounding != 1) {
2054 if (i < 0) {
2055 /* Error is less than an ulp */
2056 if (!delta->x[0] && delta->wds <= 1) {
2057 /* exact */
2058 #ifdef SET_INEXACT
2059 inexact = 0;
2060 #endif
2061 break;
2062 }
2063 if (Rounding) {
2064 if (dsign) {
2065 adj = 1.;
2066 goto apply_adj;
2067 }
2068 }
2069 else if (!dsign) {
2070 adj = -1.;
2071 if (!word1(rv)
2072 && !(word0(rv) & Frac_mask)) {
2073 y = word0(rv) & Exp_mask;
2074 #ifdef Avoid_Underflow
2075 if (!scale || y > 2*P*Exp_msk1)
2076 #else
2077 if (y)
2078 #endif
2079 {
2080 delta = lshift(delta,Log2P);
2081 if (cmp(delta, bs) <= 0)
2082 adj = -0.5;
2083 }
2084 }
2085 apply_adj:
2086 #ifdef Avoid_Underflow
2087 if (scale && (y = word0(rv) & Exp_mask)
2088 <= 2*P*Exp_msk1)
2089 word0(adj) += (2*P+1)*Exp_msk1 - y;
2090 #else
2091 #ifdef Sudden_Underflow
2092 if ((word0(rv) & Exp_mask) <=
2093 P*Exp_msk1) {
2094 word0(rv) += P*Exp_msk1;
2095 dval(rv) += adj*ulp(dval(rv));
2096 word0(rv) -= P*Exp_msk1;
2097 }
2098 else
2099 #endif /*Sudden_Underflow*/
2100 #endif /*Avoid_Underflow*/
2101 dval(rv) += adj*ulp(dval(rv));
2102 }
2103 break;
2104 }
2105 adj = ratio(delta, bs);
2106 if (adj < 1.)
2107 adj = 1.;
2108 if (adj <= 0x7ffffffe) {
2109 /* adj = rounding ? ceil(adj) : floor(adj); */
2110 y = adj;
2111 if (y != adj) {
2112 if (!((Rounding>>1) ^ dsign))
2113 y++;
2114 adj = y;
2115 }
2116 }
2117 #ifdef Avoid_Underflow
2118 if (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
2119 word0(adj) += (2*P+1)*Exp_msk1 - y;
2120 #else
2121 #ifdef Sudden_Underflow
2122 if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
2123 word0(rv) += P*Exp_msk1;
2124 adj *= ulp(dval(rv));
2125 if (dsign)
2126 dval(rv) += adj;
2127 else
2128 dval(rv) -= adj;
2129 word0(rv) -= P*Exp_msk1;
2130 goto cont;
2131 }
2132 #endif /*Sudden_Underflow*/
2133 #endif /*Avoid_Underflow*/
2134 adj *= ulp(dval(rv));
2135 if (dsign) {
2136 if (word0(rv) == Big0 && word1(rv) == Big1)
2137 goto ovfl;
2138 dval(rv) += adj;
2139 }
2140 else
2141 dval(rv) -= adj;
2142 goto cont;
2143 }
2144 #endif /*Honor_FLT_ROUNDS*/
2145
2146 if (i < 0) {
2147 /* Error is less than half an ulp -- check for
2148 * special case of mantissa a power of two.
2149 */
2150 if (dsign || word1(rv) || word0(rv) & Bndry_mask
2151 #ifdef IEEE_Arith
2152 #ifdef Avoid_Underflow
2153 || (word0(rv) & Exp_mask) <= (2*P+1)*Exp_msk1
2154 #else
2155 || (word0(rv) & Exp_mask) <= Exp_msk1
2156 #endif
2157 #endif
2158 ) {
2159 #ifdef SET_INEXACT
2160 if (!delta->x[0] && delta->wds <= 1)
2161 inexact = 0;
2162 #endif
2163 break;
2164 }
2165 if (!delta->x[0] && delta->wds <= 1) {
2166 /* exact result */
2167 #ifdef SET_INEXACT
2168 inexact = 0;
2169 #endif
2170 break;
2171 }
2172 delta = lshift(delta,Log2P);
2173 if (cmp(delta, bs) > 0)
2174 goto drop_down;
2175 break;
2176 }
2177 if (i == 0) {
2178 /* exactly half-way between */
2179 if (dsign) {
2180 if ((word0(rv) & Bndry_mask1) == Bndry_mask1
2181 && word1(rv) == (
2182 #ifdef Avoid_Underflow
2183 (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
2184 ? (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) :
2185 #endif
2186 0xffffffff)) {
2187 /*boundary case -- increment exponent*/
2188 word0(rv) = (word0(rv) & Exp_mask)
2189 + Exp_msk1
2190 #ifdef IBM
2191 | Exp_msk1 >> 4
2192 #endif
2193 ;
2194 word1(rv) = 0;
2195 #ifdef Avoid_Underflow
2196 dsign = 0;
2197 #endif
2198 break;
2199 }
2200 }
2201 else if (!(word0(rv) & Bndry_mask) && !word1(rv)) {
2202 drop_down:
2203 /* boundary case -- decrement exponent */
2204 #ifdef Sudden_Underflow /*{{*/
2205 L = word0(rv) & Exp_mask;
2206 #ifdef IBM
2207 if (L < Exp_msk1)
2208 #else
2209 #ifdef Avoid_Underflow
2210 if (L <= (scale ? (2*P+1)*Exp_msk1 : Exp_msk1))
2211 #else
2212 if (L <= Exp_msk1)
2213 #endif /*Avoid_Underflow*/
2214 #endif /*IBM*/
2215 goto undfl;
2216 L -= Exp_msk1;
2217 #else /*Sudden_Underflow}{*/
2218 #ifdef Avoid_Underflow
2219 if (scale) {
2220 L = word0(rv) & Exp_mask;
2221 if (L <= (2*P+1)*Exp_msk1) {
2222 if (L > (P+2)*Exp_msk1)
2223 /* round even ==> */
2224 /* accept rv */
2225 break;
2226 /* rv = smallest denormal */
2227 goto undfl;
2228 }
2229 }
2230 #endif /*Avoid_Underflow*/
2231 L = (word0(rv) & Exp_mask) - Exp_msk1;
2232 #endif /*Sudden_Underflow}}*/
2233 word0(rv) = L | Bndry_mask1;
2234 word1(rv) = 0xffffffff;
2235 #ifdef IBM
2236 goto cont;
2237 #else
2238 break;
2239 #endif
2240 }
2241 #ifndef ROUND_BIASED
2242 if (!(word1(rv) & LSB))
2243 break;
2244 #endif
2245 if (dsign)
2246 dval(rv) += ulp(dval(rv));
2247 #ifndef ROUND_BIASED
2248 else {
2249 dval(rv) -= ulp(dval(rv));
2250 #ifndef Sudden_Underflow
2251 if (!dval(rv))
2252 goto undfl;
2253 #endif
2254 }
2255 #ifdef Avoid_Underflow
2256 dsign = 1 - dsign;
2257 #endif
2258 #endif
2259 break;
2260 }
2261 if ((aadj = ratio(delta, bs)) <= 2.) {
2262 if (dsign)
2263 aadj = aadj1 = 1.;
2264 else if (word1(rv) || word0(rv) & Bndry_mask) {
2265 #ifndef Sudden_Underflow
2266 if (word1(rv) == Tiny1 && !word0(rv))
2267 goto undfl;
2268 #endif
2269 aadj = 1.;
2270 aadj1 = -1.;
2271 }
2272 else {
2273 /* special case -- power of FLT_RADIX to be */
2274 /* rounded down... */
2275
2276 if (aadj < 2./FLT_RADIX)
2277 aadj = 1./FLT_RADIX;
2278 else
2279 aadj *= 0.5;
2280 aadj1 = -aadj;
2281 }
2282 }
2283 else {
2284 aadj *= 0.5;
2285 aadj1 = dsign ? aadj : -aadj;
2286 #ifdef Check_FLT_ROUNDS
2287 switch(Rounding) {
2288 case 2: /* towards +infinity */
2289 aadj1 -= 0.5;
2290 break;
2291 case 0: /* towards 0 */
2292 case 3: /* towards -infinity */
2293 aadj1 += 0.5;
2294 }
2295 #else
2296 if (Flt_Rounds == 0)
2297 aadj1 += 0.5;
2298 #endif /*Check_FLT_ROUNDS*/
2299 }
2300 y = word0(rv) & Exp_mask;
2301
2302 /* Check for overflow */
2303
2304 if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
2305 dval(rv0) = dval(rv);
2306 word0(rv) -= P*Exp_msk1;
2307 adj = aadj1 * ulp(dval(rv));
2308 dval(rv) += adj;
2309 if ((word0(rv) & Exp_mask) >=
2310 Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
2311 if (word0(rv0) == Big0 && word1(rv0) == Big1)
2312 goto ovfl;
2313 word0(rv) = Big0;
2314 word1(rv) = Big1;
2315 goto cont;
2316 }
2317 else
2318 word0(rv) += P*Exp_msk1;
2319 }
2320 else {
2321 #ifdef Avoid_Underflow
2322 if (scale && y <= 2*P*Exp_msk1) {
2323 if (aadj <= 0x7fffffff) {
2324 if ((z = aadj) <= 0)
2325 z = 1;
2326 aadj = z;
2327 aadj1 = dsign ? aadj : -aadj;
2328 }
2329 word0(aadj1) += (2*P+1)*Exp_msk1 - y;
2330 }
2331 adj = aadj1 * ulp(dval(rv));
2332 dval(rv) += adj;
2333 #else
2334 #ifdef Sudden_Underflow
2335 if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
2336 dval(rv0) = dval(rv);
2337 word0(rv) += P*Exp_msk1;
2338 adj = aadj1 * ulp(dval(rv));
2339 dval(rv) += adj;
2340 #ifdef IBM
2341 if ((word0(rv) & Exp_mask) < P*Exp_msk1)
2342 #else
2343 if ((word0(rv) & Exp_mask) <= P*Exp_msk1)
2344 #endif
2345 {
2346 if (word0(rv0) == Tiny0
2347 && word1(rv0) == Tiny1)
2348 goto undfl;
2349 word0(rv) = Tiny0;
2350 word1(rv) = Tiny1;
2351 goto cont;
2352 }
2353 else
2354 word0(rv) -= P*Exp_msk1;
2355 }
2356 else {
2357 adj = aadj1 * ulp(dval(rv));
2358 dval(rv) += adj;
2359 }
2360 #else /*Sudden_Underflow*/
2361 /* Compute adj so that the IEEE rounding rules will
2362 * correctly round rv + adj in some half-way cases.
2363 * If rv * ulp(rv) is denormalized (i.e.,
2364 * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid
2365 * trouble from bits lost to denormalization;
2366 * example: 1.2e-307 .
2367 */
2368 if (y <= (P-1)*Exp_msk1 && aadj > 1.) {
2369 aadj1 = (double)(int)(aadj + 0.5);
2370 if (!dsign)
2371 aadj1 = -aadj1;
2372 }
2373 adj = aadj1 * ulp(dval(rv));
2374 dval(rv) += adj;
2375 #endif /*Sudden_Underflow*/
2376 #endif /*Avoid_Underflow*/
2377 }
2378 z = word0(rv) & Exp_mask;
2379 #ifndef SET_INEXACT
2380 #ifdef Avoid_Underflow
2381 if (!scale)
2382 #endif
2383 if (y == z) {
2384 /* Can we stop now? */
2385 L = (Long)aadj;
2386 aadj -= L;
2387 /* The tolerances below are conservative. */
2388 if (dsign || word1(rv) || word0(rv) & Bndry_mask) {
2389 if (aadj < .4999999 || aadj > .5000001)
2390 break;
2391 }
2392 else if (aadj < .4999999/FLT_RADIX)
2393 break;
2394 }
2395 #endif
2396 cont:
2397 Bfree(bb);
2398 Bfree(bd);
2399 Bfree(bs);
2400 Bfree(delta);
2401 }
2402 #ifdef SET_INEXACT
2403 if (inexact) {
2404 if (!oldinexact) {
2405 word0(rv0) = Exp_1 + (70 << Exp_shift);
2406 word1(rv0) = 0;
2407 dval(rv0) += 1.;
2408 }
2409 }
2410 else if (!oldinexact)
2411 clear_inexact();
2412 #endif
2413 #ifdef Avoid_Underflow
2414 if (scale) {
2415 word0(rv0) = Exp_1 - 2*P*Exp_msk1;
2416 word1(rv0) = 0;
2417 dval(rv) *= dval(rv0);
2418 #ifndef NO_ERRNO
2419 /* try to avoid the bug of testing an 8087 register value */
2420 #ifdef IEEE_Arith
2421 if (!(word0(rv) & Exp_mask))
2422 #else
2423 if (word0(rv) == 0 && word1(rv) == 0)
2424 #endif
2425 errno = ERANGE;
2426 #endif
2427 }
2428 #endif /* Avoid_Underflow */
2429 #ifdef SET_INEXACT
2430 if (inexact && !(word0(rv) & Exp_mask)) {
2431 /* set underflow bit */
2432 dval(rv0) = 1e-300;
2433 dval(rv0) *= dval(rv0);
2434 }
2435 #endif
2436 retfree:
2437 Bfree(bb);
2438 Bfree(bd);
2439 Bfree(bs);
2440 Bfree(bd0);
2441 Bfree(delta);
2442 ret:
2443 if (se)
2444 *se = (char *)s;
2445 return sign ? -dval(rv) : dval(rv);
2446 }
2447
2448 static int
2449 quorem
2450 #ifdef KR_headers
2451 (b, S) Bigint *b, *S;
2452 #else
2453 (Bigint *b, Bigint *S)
2454 #endif
2455 {
2456 int n;
2457 ULong *bx, *bxe, q, *sx, *sxe;
2458 #ifdef ULLong
2459 ULLong borrow, carry, y, ys;
2460 #else
2461 ULong borrow, carry, y, ys;
2462 #ifdef Pack_32
2463 ULong si, z, zs;
2464 #endif
2465 #endif
2466
2467 n = S->wds;
2468 #ifdef DEBUG
2469 /*debug*/ if (b->wds > n)
2470 /*debug*/ Bug("oversize b in quorem");
2471 #endif
2472 if (b->wds < n)
2473 return 0;
2474 sx = S->x;
2475 sxe = sx + --n;
2476 bx = b->x;
2477 bxe = bx + n;
2478 q = *bxe / (*sxe + 1); /* ensure q <= true quotient */
2479 #ifdef DEBUG
2480 /*debug*/ if (q > 9)
2481 /*debug*/ Bug("oversized quotient in quorem");
2482 #endif
2483 if (q) {
2484 borrow = 0;
2485 carry = 0;
2486 do {
2487 #ifdef ULLong
2488 ys = *sx++ * (ULLong)q + carry;
2489 carry = ys >> 32;
2490 y = *bx - (ys & FFFFFFFF) - borrow;
2491 borrow = y >> 32 & (ULong)1;
2492 *bx++ = y & FFFFFFFF;
2493 #else
2494 #ifdef Pack_32
2495 si = *sx++;
2496 ys = (si & 0xffff) * q + carry;
2497 zs = (si >> 16) * q + (ys >> 16);
2498 carry = zs >> 16;
2499 y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
2500 borrow = (y & 0x10000) >> 16;
2501 z = (*bx >> 16) - (zs & 0xffff) - borrow;
2502 borrow = (z & 0x10000) >> 16;
2503 Storeinc(bx, z, y);
2504 #else
2505 ys = *sx++ * q + carry;
2506 carry = ys >> 16;
2507 y = *bx - (ys & 0xffff) - borrow;
2508 borrow = (y & 0x10000) >> 16;
2509 *bx++ = y & 0xffff;
2510 #endif
2511 #endif
2512 }
2513 while(sx <= sxe);
2514 if (!*bxe) {
2515 bx = b->x;
2516 while(--bxe > bx && !*bxe)
2517 --n;
2518 b->wds = n;
2519 }
2520 }
2521 if (cmp(b, S) >= 0) {
2522 q++;
2523 borrow = 0;
2524 carry = 0;
2525 bx = b->x;
2526 sx = S->x;
2527 do {
2528 #ifdef ULLong
2529 ys = *sx++ + carry;
2530 carry = ys >> 32;
2531 y = *bx - (ys & FFFFFFFF) - borrow;
2532 borrow = y >> 32 & (ULong)1;
2533 *bx++ = y & FFFFFFFF;
2534 #else
2535 #ifdef Pack_32
2536 si = *sx++;
2537 ys = (si & 0xffff) + carry;
2538 zs = (si >> 16) + (ys >> 16);
2539 carry = zs >> 16;
2540 y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
2541 borrow = (y & 0x10000) >> 16;
2542 z = (*bx >> 16) - (zs & 0xffff) - borrow;
2543 borrow = (z & 0x10000) >> 16;
2544 Storeinc(bx, z, y);
2545 #else
2546 ys = *sx++ + carry;
2547 carry = ys >> 16;
2548 y = *bx - (ys & 0xffff) - borrow;
2549 borrow = (y & 0x10000) >> 16;
2550 *bx++ = y & 0xffff;
2551 #endif
2552 #endif
2553 }
2554 while(sx <= sxe);
2555 bx = b->x;
2556 bxe = bx + n;
2557 if (!*bxe) {
2558 while(--bxe > bx && !*bxe)
2559 --n;
2560 b->wds = n;
2561 }
2562 }
2563 return q;
2564 }
2565
2566 #ifndef MULTIPLE_THREADS
2567 static char *dtoa_result;
2568 #endif
2569
2570 static char *
2571 #ifdef KR_headers
2572 rv_alloc(i) int i;
2573 #else
2574 rv_alloc(int i)
2575 #endif
2576 {
2577 int j, k, *r;
2578
2579 j = sizeof(ULong);
2580 for(k = 0;
2581 sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i;
2582 j <<= 1)
2583 k++;
2584 r = (int*)Balloc(k);
2585 *r = k;
2586 return
2587 #ifndef MULTIPLE_THREADS
2588 dtoa_result =
2589 #endif
2590 (char *)(r+1);
2591 }
2592
2593 static char *
2594 #ifdef KR_headers
2595 nrv_alloc(s, rve, n) char *s, **rve; int n;
2596 #else
2597 nrv_alloc(char *s, char **rve, int n)
2598 #endif
2599 {
2600 char *rv, *t;
2601
2602 t = rv = rv_alloc(n);
2603 while(*t = *s++) t++;
2604 if (rve)
2605 *rve = t;
2606 return rv;
2607 }
2608
2609 /* freedtoa(s) must be used to free values s returned by dtoa
2610 * when MULTIPLE_THREADS is #defined. It should be used in all cases,
2611 * but for consistency with earlier versions of dtoa, it is optional
2612 * when MULTIPLE_THREADS is not defined.
2613 */
2614
2615 void
2616 #ifdef KR_headers
2617 freedtoa(s) char *s;
2618 #else
2619 freedtoa(char *s)
2620 #endif
2621 {
2622 Bigint *b = (Bigint *)((int *)s - 1);
2623 b->maxwds = 1 << (b->k = *(int*)b);
2624 Bfree(b);
2625 #ifndef MULTIPLE_THREADS
2626 if (s == dtoa_result)
2627 dtoa_result = 0;
2628 #endif
2629 }
2630
2631 /* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.
2632 *
2633 * Inspired by "How to Print Floating-Point Numbers Accurately" by
2634 * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 112-126].
2635 *
2636 * Modifications:
2637 * 1. Rather than iterating, we use a simple numeric overestimate
2638 * to determine k = floor(log10(d)). We scale relevant
2639 * quantities using O(log2(k)) rather than O(k) multiplications.
2640 * 2. For some modes > 2 (corresponding to ecvt and fcvt), we don't
2641 * try to generate digits strictly left to right. Instead, we
2642 * compute with fewer bits and propagate the carry if necessary
2643 * when rounding the final digit up. This is often faster.
2644 * 3. Under the assumption that input will be rounded nearest,
2645 * mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22.
2646 * That is, we allow equality in stopping tests when the
2647 * round-nearest rule will give the same floating-point value
2648 * as would satisfaction of the stopping test with strict
2649 * inequality.
2650 * 4. We remove common factors of powers of 2 from relevant
2651 * quantities.
2652 * 5. When converting floating-point integers less than 1e16,
2653 * we use floating-point arithmetic rather than resorting
2654 * to multiple-precision integers.
2655 * 6. When asked to produce fewer than 15 digits, we first try
2656 * to get by with floating-point arithmetic; we resort to
2657 * multiple-precision integer arithmetic only if we cannot
2658 * guarantee that the floating-point calculation has given
2659 * the correctly rounded result. For k requested digits and
2660 * "uniformly" distributed input, the probability is
2661 * something like 10^(k-15) that we must resort to the Long
2662 * calculation.
2663 */
2664
2665 char *
2666 dtoa
2667 #ifdef KR_headers
2668 (d, mode, ndigits, decpt, sign, rve)
2669 double d; int mode, ndigits, *decpt, *sign; char **rve;
2670 #else
2671 (double d, int mode, int ndigits, int *decpt, int *sign, char **rve)
2672 #endif
2673 {
2674 /* Arguments ndigits, decpt, sign are similar to those
2675 of ecvt and fcvt; trailing zeros are suppressed from
2676 the returned string. If not null, *rve is set to point
2677 to the end of the return value. If d is +-Infinity or NaN,
2678 then *decpt is set to 9999.
2679
2680 mode:
2681 0 ==> shortest string that yields d when read in
2682 and rounded to nearest.
2683 1 ==> like 0, but with Steele & White stopping rule;
2684 e.g. with IEEE P754 arithmetic , mode 0 gives
2685 1e23 whereas mode 1 gives 9.999999999999999e22.
2686 2 ==> max(1,ndigits) significant digits. This gives a
2687 return value similar to that of ecvt, except
2688 that trailing zeros are suppressed.
2689 3 ==> through ndigits past the decimal point. This
2690 gives a return value similar to that from fcvt,
2691 except that trailing zeros are suppressed, and
2692 ndigits can be negative.
2693 4,5 ==> similar to 2 and 3, respectively, but (in
2694 round-nearest mode) with the tests of mode 0 to
2695 possibly return a shorter string that rounds to d.
2696 With IEEE arithmetic and compilation with
2697 -DHonor_FLT_ROUNDS, modes 4 and 5 behave the same
2698 as modes 2 and 3 when FLT_ROUNDS != 1.
2699 6-9 ==> Debugging modes similar to mode - 4: don't try
2700 fast floating-point estimate (if applicable).
2701
2702 Values of mode other than 0-9 are treated as mode 0.
2703
2704 Sufficient space is allocated to the return value
2705 to hold the suppressed trailing zeros.
2706 */
2707
2708 int bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1,
2709 j, j1, k, k0, k_check, leftright, m2, m5, s2, s5,
2710 spec_case, try_quick;
2711 Long L;
2712 #ifndef Sudden_Underflow
2713 int denorm;
2714 ULong x;
2715 #endif
2716 Bigint *b, *b1, *delta, *mlo, *mhi, *S;
2717 double d2, ds, eps;
2718 char *s, *s0;
2719 #ifdef SET_INEXACT
2720 int inexact, oldinexact;
2721 #endif
2722 #ifdef Honor_FLT_ROUNDS /*{*/
2723 int Rounding;
2724 #ifdef Trust_FLT_ROUNDS /*{{ only define this if FLT_ROUNDS really works! */
2725 Rounding = Flt_Rounds;
2726 #else /*}{*/
2727 Rounding = 1;
2728 switch(fegetround()) {
2729 case FE_TOWARDZERO: Rounding = 0; break;
2730 case FE_UPWARD: Rounding = 2; break;
2731 case FE_DOWNWARD: Rounding = 3;
2732 }
2733 #endif /*}}*/
2734 #endif /*}*/
2735
2736 #ifndef MULTIPLE_THREADS
2737 if (dtoa_result) {
2738 freedtoa(dtoa_result);
2739 dtoa_result = 0;
2740 }
2741 #endif
2742
2743 if (word0(d) & Sign_bit) {
2744 /* set sign for everything, including 0's and NaNs */
2745 *sign = 1;
2746 word0(d) &= ~Sign_bit; /* clear sign bit */
2747 }
2748 else
2749 *sign = 0;
2750
2751 #if defined(IEEE_Arith) + defined(VAX)
2752 #ifdef IEEE_Arith
2753 if ((word0(d) & Exp_mask) == Exp_mask)
2754 #else
2755 if (word0(d) == 0x8000)
2756 #endif
2757 {
2758 /* Infinity or NaN */
2759 *decpt = 9999;
2760 #ifdef IEEE_Arith
2761 if (!word1(d) && !(word0(d) & 0xfffff))
2762 return nrv_alloc("Infinity", rve, 8);
2763 #endif
2764 return nrv_alloc("NaN", rve, 3);
2765 }
2766 #endif
2767 #ifdef IBM
2768 dval(d) += 0; /* normalize */
2769 #endif
2770 if (!dval(d)) {
2771 *decpt = 1;
2772 return nrv_alloc("0", rve, 1);
2773 }
2774
2775 #ifdef SET_INEXACT
2776 try_quick = oldinexact = get_inexact();
2777 inexact = 1;
2778 #endif
2779 #ifdef Honor_FLT_ROUNDS
2780 if (Rounding >= 2) {
2781 if (*sign)
2782 Rounding = Rounding == 2 ? 0 : 2;
2783 else
2784 if (Rounding != 2)
2785 Rounding = 0;
2786 }
2787 #endif
2788
2789 b = d2b(dval(d), &be, &bbits);
2790 #ifdef Sudden_Underflow
2791 i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1));
2792 #else
2793 if (i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1))) {
2794 #endif
2795 dval(d2) = dval(d);
2796 word0(d2) &= Frac_mask1;
2797 word0(d2) |= Exp_11;
2798 #ifdef IBM
2799 if (j = 11 - hi0bits(word0(d2) & Frac_mask))
2800 dval(d2) /= 1 << j;
2801 #endif
2802
2803 /* log(x) ~=~ log(1.5) + (x-1.5)/1.5
2804 * log10(x) = log(x) / log(10)
2805 * ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
2806 * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
2807 *
2808 * This suggests computing an approximation k to log10(d) by
2809 *
2810 * k = (i - Bias)*0.301029995663981
2811 * + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );
2812 *
2813 * We want k to be too large rather than too small.
2814 * The error in the first-order Taylor series approximation
2815 * is in our favor, so we just round up the constant enough
2816 * to compensate for any error in the multiplication of
2817 * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077,
2818 * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14,
2819 * adding 1e-13 to the constant term more than suffices.
2820 * Hence we adjust the constant term to 0.1760912590558.
2821 * (We could get a more accurate k by invoking log10,
2822 * but this is probably not worthwhile.)
2823 */
2824
2825 i -= Bias;
2826 #ifdef IBM
2827 i <<= 2;
2828 i += j;
2829 #endif
2830 #ifndef Sudden_Underflow
2831 denorm = 0;
2832 }
2833 else {
2834 /* d is denormalized */
2835
2836 i = bbits + be + (Bias + (P-1) - 1);
2837 x = i > 32 ? word0(d) << 64 - i | word1(d) >> i - 32
2838 : word1(d) << 32 - i;
2839 dval(d2) = x;
2840 word0(d2) -= 31*Exp_msk1; /* adjust exponent */
2841 i -= (Bias + (P-1) - 1) + 1;
2842 denorm = 1;
2843 }
2844 #endif
2845 ds = (dval(d2)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.3010299956 63981;
2846 k = (int)ds;
2847 if (ds < 0. && ds != k)
2848 k--; /* want k = floor(ds) */
2849 k_check = 1;
2850 if (k >= 0 && k <= Ten_pmax) {
2851 if (dval(d) < tens[k])
2852 k--;
2853 k_check = 0;
2854 }
2855 j = bbits - i - 1;
2856 if (j >= 0) {
2857 b2 = 0;
2858 s2 = j;
2859 }
2860 else {
2861 b2 = -j;
2862 s2 = 0;
2863 }
2864 if (k >= 0) {
2865 b5 = 0;
2866 s5 = k;
2867 s2 += k;
2868 }
2869 else {
2870 b2 -= k;
2871 b5 = -k;
2872 s5 = 0;
2873 }
2874 if (mode < 0 || mode > 9)
2875 mode = 0;
2876
2877 #ifndef SET_INEXACT
2878 #ifdef Check_FLT_ROUNDS
2879 try_quick = Rounding == 1;
2880 #else
2881 try_quick = 1;
2882 #endif
2883 #endif /*SET_INEXACT*/
2884
2885 if (mode > 5) {
2886 mode -= 4;
2887 try_quick = 0;
2888 }
2889 leftright = 1;
2890 switch(mode) {
2891 case 0:
2892 case 1:
2893 ilim = ilim1 = -1;
2894 i = 18;
2895 ndigits = 0;
2896 break;
2897 case 2:
2898 leftright = 0;
2899 /* no break */
2900 case 4:
2901 if (ndigits <= 0)
2902 ndigits = 1;
2903 ilim = ilim1 = i = ndigits;
2904 break;
2905 case 3:
2906 leftright = 0;
2907 /* no break */
2908 case 5:
2909 i = ndigits + k + 1;
2910 ilim = i;
2911 ilim1 = i - 1;
2912 if (i <= 0)
2913 i = 1;
2914 }
2915 s = s0 = rv_alloc(i);
2916
2917 #ifdef Honor_FLT_ROUNDS
2918 if (mode > 1 && Rounding != 1)
2919 leftright = 0;
2920 #endif
2921
2922 if (ilim >= 0 && ilim <= Quick_max && try_quick) {
2923
2924 /* Try to get by with floating-point arithmetic. */
2925
2926 i = 0;
2927 dval(d2) = dval(d);
2928 k0 = k;
2929 ilim0 = ilim;
2930 ieps = 2; /* conservative */
2931 if (k > 0) {
2932 ds = tens[k&0xf];
2933 j = k >> 4;
2934 if (j & Bletch) {
2935 /* prevent overflows */
2936 j &= Bletch - 1;
2937 dval(d) /= bigtens[n_bigtens-1];
2938 ieps++;
2939 }
2940 for(; j; j >>= 1, i++)
2941 if (j & 1) {
2942 ieps++;
2943 ds *= bigtens[i];
2944 }
2945 dval(d) /= ds;
2946 }
2947 else if (j1 = -k) {
2948 dval(d) *= tens[j1 & 0xf];
2949 for(j = j1 >> 4; j; j >>= 1, i++)
2950 if (j & 1) {
2951 ieps++;
2952 dval(d) *= bigtens[i];
2953 }
2954 }
2955 if (k_check && dval(d) < 1. && ilim > 0) {
2956 if (ilim1 <= 0)
2957 goto fast_failed;
2958 ilim = ilim1;
2959 k--;
2960 dval(d) *= 10.;
2961 ieps++;
2962 }
2963 dval(eps) = ieps*dval(d) + 7.;
2964 word0(eps) -= (P-1)*Exp_msk1;
2965 if (ilim == 0) {
2966 S = mhi = 0;
2967 dval(d) -= 5.;
2968 if (dval(d) > dval(eps))
2969 goto one_digit;
2970 if (dval(d) < -dval(eps))
2971 goto no_digits;
2972 goto fast_failed;
2973 }
2974 #ifndef No_leftright
2975 if (leftright) {
2976 /* Use Steele & White method of only
2977 * generating digits needed.
2978 */
2979 dval(eps) = 0.5/tens[ilim-1] - dval(eps);
2980 for(i = 0;;) {
2981 L = dval(d);
2982 dval(d) -= L;
2983 *s++ = '0' + (int)L;
2984 if (dval(d) < dval(eps))
2985 goto ret1;
2986 if (1. - dval(d) < dval(eps))
2987 goto bump_up;
2988 if (++i >= ilim)
2989 break;
2990 dval(eps) *= 10.;
2991 dval(d) *= 10.;
2992 }
2993 }
2994 else {
2995 #endif
2996 /* Generate ilim digits, then fix them up. */
2997 dval(eps) *= tens[ilim-1];
2998 for(i = 1;; i++, dval(d) *= 10.) {
2999 L = (Long)(dval(d));
3000 if (!(dval(d) -= L))
3001 ilim = i;
3002 *s++ = '0' + (int)L;
3003 if (i == ilim) {
3004 if (dval(d) > 0.5 + dval(eps))
3005 goto bump_up;
3006 else if (dval(d) < 0.5 - dval(eps)) {
3007 while(*--s == '0');
3008 s++;
3009 goto ret1;
3010 }
3011 break;
3012 }
3013 }
3014 #ifndef No_leftright
3015 }
3016 #endif
3017 fast_failed:
3018 s = s0;
3019 dval(d) = dval(d2);
3020 k = k0;
3021 ilim = ilim0;
3022 }
3023
3024 /* Do we have a "small" integer? */
3025
3026 if (be >= 0 && k <= Int_max) {
3027 /* Yes. */
3028 ds = tens[k];
3029 if (ndigits < 0 && ilim <= 0) {
3030 S = mhi = 0;
3031 if (ilim < 0 || dval(d) <= 5*ds)
3032 goto no_digits;
3033 goto one_digit;
3034 }
3035 for(i = 1;; i++, dval(d) *= 10.) {
3036 L = (Long)(dval(d) / ds);
3037 dval(d) -= L*ds;
3038 #ifdef Check_FLT_ROUNDS
3039 /* If FLT_ROUNDS == 2, L will usually be high by 1 */
3040 if (dval(d) < 0) {
3041 L--;
3042 dval(d) += ds;
3043 }
3044 #endif
3045 *s++ = '0' + (int)L;
3046 if (!dval(d)) {
3047 #ifdef SET_INEXACT
3048 inexact = 0;
3049 #endif
3050 break;
3051 }
3052 if (i == ilim) {
3053 #ifdef Honor_FLT_ROUNDS
3054 if (mode > 1)
3055 switch(Rounding) {
3056 case 0: goto ret1;
3057 case 2: goto bump_up;
3058 }
3059 #endif
3060 dval(d) += dval(d);
3061 if (dval(d) > ds || dval(d) == ds && L & 1) {
3062 bump_up:
3063 while(*--s == '9')
3064 if (s == s0) {
3065 k++;
3066 *s = '0';
3067 break;
3068 }
3069 ++*s++;
3070 }
3071 break;
3072 }
3073 }
3074 goto ret1;
3075 }
3076
3077 m2 = b2;
3078 m5 = b5;
3079 mhi = mlo = 0;
3080 if (leftright) {
3081 i =
3082 #ifndef Sudden_Underflow
3083 denorm ? be + (Bias + (P-1) - 1 + 1) :
3084 #endif
3085 #ifdef IBM
3086 1 + 4*P - 3 - bbits + ((bbits + be - 1) & 3);
3087 #else
3088 1 + P - bbits;
3089 #endif
3090 b2 += i;
3091 s2 += i;
3092 mhi = i2b(1);
3093 }
3094 if (m2 > 0 && s2 > 0) {
3095 i = m2 < s2 ? m2 : s2;
3096 b2 -= i;
3097 m2 -= i;
3098 s2 -= i;
3099 }
3100 if (b5 > 0) {
3101 if (leftright) {
3102 if (m5 > 0) {
3103 mhi = pow5mult(mhi, m5);
3104 b1 = mult(mhi, b);
3105 Bfree(b);
3106 b = b1;
3107 }
3108 if (j = b5 - m5)
3109 b = pow5mult(b, j);
3110 }
3111 else
3112 b = pow5mult(b, b5);
3113 }
3114 S = i2b(1);
3115 if (s5 > 0)
3116 S = pow5mult(S, s5);
3117
3118 /* Check for special case that d is a normalized power of 2. */
3119
3120 spec_case = 0;
3121 if ((mode < 2 || leftright)
3122 #ifdef Honor_FLT_ROUNDS
3123 && Rounding == 1
3124 #endif
3125 ) {
3126 if (!word1(d) && !(word0(d) & Bndry_mask)
3127 #ifndef Sudden_Underflow
3128 && word0(d) & (Exp_mask & ~Exp_msk1)
3129 #endif
3130 ) {
3131 /* The special case */
3132 b2 += Log2P;
3133 s2 += Log2P;
3134 spec_case = 1;
3135 }
3136 }
3137
3138 /* Arrange for convenient computation of quotients:
3139 * shift left if necessary so divisor has 4 leading 0 bits.
3140 *
3141 * Perhaps we should just compute leading 28 bits of S once
3142 * and for all and pass them and a shift to quorem, so it
3143 * can do shifts and ors to compute the numerator for q.
3144 */
3145 #ifdef Pack_32
3146 if (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f)
3147 i = 32 - i;
3148 #else
3149 if (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0xf)
3150 i = 16 - i;
3151 #endif
3152 if (i > 4) {
3153 i -= 4;
3154 b2 += i;
3155 m2 += i;
3156 s2 += i;
3157 }
3158 else if (i < 4) {
3159 i += 28;
3160 b2 += i;
3161 m2 += i;
3162 s2 += i;
3163 }
3164 if (b2 > 0)
3165 b = lshift(b, b2);
3166 if (s2 > 0)
3167 S = lshift(S, s2);
3168 if (k_check) {
3169 if (cmp(b,S) < 0) {
3170 k--;
3171 b = multadd(b, 10, 0); /* we botched the k estimate */
3172 if (leftright)
3173 mhi = multadd(mhi, 10, 0);
3174 ilim = ilim1;
3175 }
3176 }
3177 if (ilim <= 0 && (mode == 3 || mode == 5)) {
3178 if (ilim < 0 || cmp(b,S = multadd(S,5,0)) <= 0) {
3179 /* no digits, fcvt style */
3180 no_digits:
3181 k = -1 - ndigits;
3182 goto ret;
3183 }
3184 one_digit:
3185 *s++ = '1';
3186 k++;
3187 goto ret;
3188 }
3189 if (leftright) {
3190 if (m2 > 0)
3191 mhi = lshift(mhi, m2);
3192
3193 /* Compute mlo -- check for special case
3194 * that d is a normalized power of 2.
3195 */
3196
3197 mlo = mhi;
3198 if (spec_case) {
3199 mhi = Balloc(mhi->k);
3200 Bcopy(mhi, mlo);
3201 mhi = lshift(mhi, Log2P);
3202 }
3203
3204 for(i = 1;;i++) {
3205 dig = quorem(b,S) + '0';
3206 /* Do we yet have the shortest decimal string
3207 * that will round to d?
3208 */
3209 j = cmp(b, mlo);
3210 delta = diff(S, mhi);
3211 j1 = delta->sign ? 1 : cmp(b, delta);
3212 Bfree(delta);
3213 #ifndef ROUND_BIASED
3214 if (j1 == 0 && mode != 1 && !(word1(d) & 1)
3215 #ifdef Honor_FLT_ROUNDS
3216 && Rounding >= 1
3217 #endif
3218 ) {
3219 if (dig == '9')
3220 goto round_9_up;
3221 if (j > 0)
3222 dig++;
3223 #ifdef SET_INEXACT
3224 else if (!b->x[0] && b->wds <= 1)
3225 inexact = 0;
3226 #endif
3227 *s++ = dig;
3228 goto ret;
3229 }
3230 #endif
3231 if (j < 0 || j == 0 && mode != 1
3232 #ifndef ROUND_BIASED
3233 && !(word1(d) & 1)
3234 #endif
3235 ) {
3236 if (!b->x[0] && b->wds <= 1) {
3237 #ifdef SET_INEXACT
3238 inexact = 0;
3239 #endif
3240 goto accept_dig;
3241 }
3242 #ifdef Honor_FLT_ROUNDS
3243 if (mode > 1)
3244 switch(Rounding) {
3245 case 0: goto accept_dig;
3246 case 2: goto keep_dig;
3247 }
3248 #endif /*Honor_FLT_ROUNDS*/
3249 if (j1 > 0) {
3250 b = lshift(b, 1);
3251 j1 = cmp(b, S);
3252 if ((j1 > 0 || j1 == 0 && dig & 1)
3253 && dig++ == '9')
3254 goto round_9_up;
3255 }
3256 accept_dig:
3257 *s++ = dig;
3258 goto ret;
3259 }
3260 if (j1 > 0) {
3261 #ifdef Honor_FLT_ROUNDS
3262 if (!Rounding)
3263 goto accept_dig;
3264 #endif
3265 if (dig == '9') { /* possible if i == 1 */
3266 round_9_up:
3267 *s++ = '9';
3268 goto roundoff;
3269 }
3270 *s++ = dig + 1;
3271 goto ret;
3272 }
3273 #ifdef Honor_FLT_ROUNDS
3274 keep_dig:
3275 #endif
3276 *s++ = dig;
3277 if (i == ilim)
3278 break;
3279 b = multadd(b, 10, 0);
3280 if (mlo == mhi)
3281 mlo = mhi = multadd(mhi, 10, 0);
3282 else {
3283 mlo = multadd(mlo, 10, 0);
3284 mhi = multadd(mhi, 10, 0);
3285 }
3286 }
3287 }
3288 else
3289 for(i = 1;; i++) {
3290 *s++ = dig = quorem(b,S) + '0';
3291 if (!b->x[0] && b->wds <= 1) {
3292 #ifdef SET_INEXACT
3293 inexact = 0;
3294 #endif
3295 goto ret;
3296 }
3297 if (i >= ilim)
3298 break;
3299 b = multadd(b, 10, 0);
3300 }
3301
3302 /* Round off last digit */
3303
3304 #ifdef Honor_FLT_ROUNDS
3305 switch(Rounding) {
3306 case 0: goto trimzeros;
3307 case 2: goto roundoff;
3308 }
3309 #endif
3310 b = lshift(b, 1);
3311 j = cmp(b, S);
3312 if (j > 0 || j == 0 && dig & 1) {
3313 roundoff:
3314 while(*--s == '9')
3315 if (s == s0) {
3316 k++;
3317 *s++ = '1';
3318 goto ret;
3319 }
3320 ++*s++;
3321 }
3322 else {
3323 trimzeros:
3324 while(*--s == '0');
3325 s++;
3326 }
3327 ret:
3328 Bfree(S);
3329 if (mhi) {
3330 if (mlo && mlo != mhi)
3331 Bfree(mlo);
3332 Bfree(mhi);
3333 }
3334 ret1:
3335 #ifdef SET_INEXACT
3336 if (inexact) {
3337 if (!oldinexact) {
3338 word0(d) = Exp_1 + (70 << Exp_shift);
3339 word1(d) = 0;
3340 dval(d) += 1.;
3341 }
3342 }
3343 else if (!oldinexact)
3344 clear_inexact();
3345 #endif
3346 Bfree(b);
3347 *s = 0;
3348 *decpt = k + 1;
3349 if (rve)
3350 *rve = s;
3351 return s0;
3352 }
3353
3354 } // namespace dmg_fp
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