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1/****************************************************************
2
3The author of this software is David M. Gay.
4
5Copyright (C) 1998-2000 by Lucent Technologies
6All Rights Reserved
7
8Permission to use, copy, modify, and distribute this software and
9its documentation for any purpose and without fee is hereby
10granted, provided that the above copyright notice appear in all
11copies and that both that the copyright notice and this
12permission notice and warranty disclaimer appear in supporting
13documentation, and that the name of Lucent or any of its entities
14not be used in advertising or publicity pertaining to
15distribution of the software without specific, written prior
16permission.
17
18LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
19INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
20IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
21SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
22WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
23IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
24ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
25THIS SOFTWARE.
26
27****************************************************************/
28
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29/* This is a variation on dtoa.c that converts arbitary binary
30 floating-point formats to and from decimal notation. It uses
31 double-precision arithmetic internally, so there are still
32 various #ifdefs that adapt the calculations to the native
33 double-precision arithmetic (any of IEEE, VAX D_floating,
34 or IBM mainframe arithmetic).
35
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36 Please send bug reports to David M. Gay (dmg at acm dot org,
37 with " at " changed at "@" and " dot " changed to ".").
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38 */
39
40/* On a machine with IEEE extended-precision registers, it is
41 * necessary to specify double-precision (53-bit) rounding precision
42 * before invoking strtod or dtoa. If the machine uses (the equivalent
43 * of) Intel 80x87 arithmetic, the call
44 * _control87(PC_53, MCW_PC);
45 * does this with many compilers. Whether this or another call is
46 * appropriate depends on the compiler; for this to work, it may be
47 * necessary to #include "float.h" or another system-dependent header
48 * file.
49 */
50
51/* strtod for IEEE-, VAX-, and IBM-arithmetic machines.
52 *
53 * This strtod returns a nearest machine number to the input decimal
54 * string (or sets errno to ERANGE). With IEEE arithmetic, ties are
55 * broken by the IEEE round-even rule. Otherwise ties are broken by
56 * biased rounding (add half and chop).
57 *
58 * Inspired loosely by William D. Clinger's paper "How to Read Floating
3d9156a7 59 * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 112-126].
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60 *
61 * Modifications:
62 *
63 * 1. We only require IEEE, IBM, or VAX double-precision
64 * arithmetic (not IEEE double-extended).
65 * 2. We get by with floating-point arithmetic in a case that
66 * Clinger missed -- when we're computing d * 10^n
67 * for a small integer d and the integer n is not too
68 * much larger than 22 (the maximum integer k for which
69 * we can represent 10^k exactly), we may be able to
70 * compute (d*10^k) * 10^(e-k) with just one roundoff.
71 * 3. Rather than a bit-at-a-time adjustment of the binary
72 * result in the hard case, we use floating-point
73 * arithmetic to determine the adjustment to within
74 * one bit; only in really hard cases do we need to
75 * compute a second residual.
76 * 4. Because of 3., we don't need a large table of powers of 10
77 * for ten-to-e (just some small tables, e.g. of 10^k
78 * for 0 <= k <= 22).
79 */
80
81/*
82 * #define IEEE_8087 for IEEE-arithmetic machines where the least
83 * significant byte has the lowest address.
84 * #define IEEE_MC68k for IEEE-arithmetic machines where the most
85 * significant byte has the lowest address.
86 * #define Long int on machines with 32-bit ints and 64-bit longs.
87 * #define Sudden_Underflow for IEEE-format machines without gradual
88 * underflow (i.e., that flush to zero on underflow).
89 * #define IBM for IBM mainframe-style floating-point arithmetic.
90 * #define VAX for VAX-style floating-point arithmetic (D_floating).
91 * #define No_leftright to omit left-right logic in fast floating-point
92 * computation of dtoa.
93 * #define Check_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3.
94 * #define RND_PRODQUOT to use rnd_prod and rnd_quot (assembly routines
95 * that use extended-precision instructions to compute rounded
96 * products and quotients) with IBM.
97 * #define ROUND_BIASED for IEEE-format with biased rounding.
98 * #define Inaccurate_Divide for IEEE-format with correctly rounded
99 * products but inaccurate quotients, e.g., for Intel i860.
100 * #define NO_LONG_LONG on machines that do not have a "long long"
101 * integer type (of >= 64 bits). On such machines, you can
102 * #define Just_16 to store 16 bits per 32-bit Long when doing
103 * high-precision integer arithmetic. Whether this speeds things
104 * up or slows things down depends on the machine and the number
105 * being converted. If long long is available and the name is
106 * something other than "long long", #define Llong to be the name,
107 * and if "unsigned Llong" does not work as an unsigned version of
108 * Llong, #define #ULLong to be the corresponding unsigned type.
109 * #define KR_headers for old-style C function headers.
110 * #define Bad_float_h if your system lacks a float.h or if it does not
111 * define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP,
112 * FLT_RADIX, FLT_ROUNDS, and DBL_MAX.
113 * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n)
114 * if memory is available and otherwise does something you deem
115 * appropriate. If MALLOC is undefined, malloc will be invoked
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116 * directly -- and assumed always to succeed. Similarly, if you
117 * want something other than the system's free() to be called to
118 * recycle memory acquired from MALLOC, #define FREE to be the
119 * name of the alternate routine. (FREE or free is only called in
120 * pathological cases, e.g., in a gdtoa call after a gdtoa return in
121 * mode 3 with thousands of digits requested.)
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122 * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
123 * memory allocations from a private pool of memory when possible.
124 * When used, the private pool is PRIVATE_MEM bytes long: 2304 bytes,
125 * unless #defined to be a different length. This default length
126 * suffices to get rid of MALLOC calls except for unusual cases,
127 * such as decimal-to-binary conversion of a very long string of
128 * digits. When converting IEEE double precision values, the
129 * longest string gdtoa can return is about 751 bytes long. For
130 * conversions by strtod of strings of 800 digits and all gdtoa
131 * conversions of IEEE doubles in single-threaded executions with
132 * 8-byte pointers, PRIVATE_MEM >= 7400 appears to suffice; with
133 * 4-byte pointers, PRIVATE_MEM >= 7112 appears adequate.
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134 * #define NO_INFNAN_CHECK if you do not wish to have INFNAN_CHECK
135 * #defined automatically on IEEE systems. On such systems,
136 * when INFNAN_CHECK is #defined, strtod checks
137 * for Infinity and NaN (case insensitively).
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138 * When INFNAN_CHECK is #defined and No_Hex_NaN is not #defined,
139 * strtodg also accepts (case insensitively) strings of the form
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140 * NaN(x), where x is a string of hexadecimal digits (optionally
141 * preceded by 0x or 0X) and spaces; if there is only one string
142 * of hexadecimal digits, it is taken for the fraction bits of the
143 * resulting NaN; if there are two or more strings of hexadecimal
144 * digits, each string is assigned to the next available sequence
145 * of 32-bit words of fractions bits (starting with the most
146 * significant), right-aligned in each sequence.
147 * Unless GDTOA_NON_PEDANTIC_NANCHECK is #defined, input "NaN(...)"
148 * is consumed even when ... has the wrong form (in which case the
149 * "(...)" is consumed but ignored).
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150 * #define MULTIPLE_THREADS if the system offers preemptively scheduled
151 * multiple threads. In this case, you must provide (or suitably
152 * #define) two locks, acquired by ACQUIRE_DTOA_LOCK(n) and freed
153 * by FREE_DTOA_LOCK(n) for n = 0 or 1. (The second lock, accessed
154 * in pow5mult, ensures lazy evaluation of only one copy of high
155 * powers of 5; omitting this lock would introduce a small
156 * probability of wasting memory, but would otherwise be harmless.)
157 * You must also invoke freedtoa(s) to free the value s returned by
158 * dtoa. You may do so whether or not MULTIPLE_THREADS is #defined.
159 * #define IMPRECISE_INEXACT if you do not care about the setting of
160 * the STRTOG_Inexact bits in the special case of doing IEEE double
34e8f829 161 * precision conversions (which could also be done by the strtod in
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162 * dtoa.c).
163 * #define NO_HEX_FP to disable recognition of C9x's hexadecimal
164 * floating-point constants.
165 * #define -DNO_ERRNO to suppress setting errno (in strtod.c and
166 * strtodg.c).
167 * #define NO_STRING_H to use private versions of memcpy.
168 * On some K&R systems, it may also be necessary to
169 * #define DECLARE_SIZE_T in this case.
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170 * #define USE_LOCALE to use the current locale's decimal_point value.
171 */
172
173#ifndef GDTOAIMP_H_INCLUDED
174#define GDTOAIMP_H_INCLUDED
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175/*
176 * Paranoia: Protect exported symbols, including ones in files we don't
177 * compile right now. The standard strtof and strtod survive.
178 */
179#define dtoa __dtoa
180#define gdtoa __gdtoa
181#define freedtoa __freedtoa
182#define strtodg __strtodg
183#define g_ddfmt __g_ddfmt
184#define g_dfmt __g_dfmt
185#define g_ffmt __g_ffmt
186#define g_Qfmt __g_Qfmt
187#define g_xfmt __g_xfmt
188#define g_xLfmt __g_xLfmt
189#define strtoId __strtoId
190#define strtoIdd __strtoIdd
191#define strtoIf __strtoIf
192#define strtoIQ __strtoIQ
193#define strtoIx __strtoIx
194#define strtoIxL __strtoIxL
195#define strtord __strtord
196#define strtordd __strtordd
197#define strtorf __strtorf
198#define strtorQ __strtorQ
199#define strtorx __strtorx
200#define strtorxL __strtorxL
201#define strtodI __strtodI
202#define strtopd __strtopd
203#define strtopdd __strtopdd
204#define strtopf __strtopf
205#define strtopQ __strtopQ
206#define strtopx __strtopx
207#define strtopxL __strtopxL
208
209/* Protect gdtoa-internal symbols */
210#define Balloc __Balloc_D2A
211#define Bfree __Bfree_D2A
212#define ULtoQ __ULtoQ_D2A
213#define ULtof __ULtof_D2A
214#define ULtod __ULtod_D2A
215#define ULtodd __ULtodd_D2A
216#define ULtox __ULtox_D2A
217#define ULtoxL __ULtoxL_D2A
218#define any_on __any_on_D2A
219#define b2d __b2d_D2A
220#define bigtens __bigtens_D2A
221#define cmp __cmp_D2A
222#define copybits __copybits_D2A
223#define d2b __d2b_D2A
224#define decrement __decrement_D2A
225#define diff __diff_D2A
226#define dtoa_result __dtoa_result_D2A
227#define g__fmt __g__fmt_D2A
228#define gethex __gethex_D2A
229#define hexdig __hexdig_D2A
230#define hexdig_init_D2A __hexdig_init_D2A
231#define hexnan __hexnan_D2A
232#define hi0bits __hi0bits_D2A
233#define hi0bits_D2A __hi0bits_D2A
234#define i2b __i2b_D2A
235#define increment __increment_D2A
236#define lo0bits __lo0bits_D2A
237#define lshift __lshift_D2A
238#define match __match_D2A
239#define mult __mult_D2A
240#define multadd __multadd_D2A
241#define nrv_alloc __nrv_alloc_D2A
242#define pow5mult __pow5mult_D2A
243#define quorem __quorem_D2A
244#define ratio __ratio_D2A
245#define rshift __rshift_D2A
246#define rv_alloc __rv_alloc_D2A
247#define s2b __s2b_D2A
248#define set_ones __set_ones_D2A
249#define strcp __strcp_D2A
250#define strcp_D2A __strcp_D2A
251#define strtoIg __strtoIg_D2A
252#define sum __sum_D2A
253#define tens __tens_D2A
254#define tinytens __tinytens_D2A
255#define tinytens __tinytens_D2A
256#define trailz __trailz_D2A
257#define ulp __ulp_D2A
258
259#include <xlocale.h>
9385eb3d 260#include "gdtoa.h"
3d9156a7 261#include "gd_qnan.h"
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262#ifdef Honor_FLT_ROUNDS
263#include <fenv.h>
264#endif
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265
266#ifdef DEBUG
267#include "stdio.h"
268#define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
269#endif
270
ad3c9f2a 271#include "limits.h"
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272#include "stdlib.h"
273#include "string.h"
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274#include "libc_private.h"
275#include "spinlock.h"
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276
277#ifdef KR_headers
278#define Char char
279#else
280#define Char void
281#endif
282
283#ifdef MALLOC
284extern Char *MALLOC ANSI((size_t));
285#else
286#define MALLOC malloc
287#endif
288
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289#define INFNAN_CHECK
290#define USE_LOCALE
291#define NO_LOCALE_CACHE
292
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293#undef IEEE_Arith
294#undef Avoid_Underflow
295#ifdef IEEE_MC68k
296#define IEEE_Arith
297#endif
298#ifdef IEEE_8087
299#define IEEE_Arith
300#endif
301
302#include "errno.h"
303#ifdef Bad_float_h
304
305#ifdef IEEE_Arith
306#define DBL_DIG 15
307#define DBL_MAX_10_EXP 308
308#define DBL_MAX_EXP 1024
309#define FLT_RADIX 2
310#define DBL_MAX 1.7976931348623157e+308
311#endif
312
313#ifdef IBM
314#define DBL_DIG 16
315#define DBL_MAX_10_EXP 75
316#define DBL_MAX_EXP 63
317#define FLT_RADIX 16
318#define DBL_MAX 7.2370055773322621e+75
319#endif
320
321#ifdef VAX
322#define DBL_DIG 16
323#define DBL_MAX_10_EXP 38
324#define DBL_MAX_EXP 127
325#define FLT_RADIX 2
326#define DBL_MAX 1.7014118346046923e+38
327#define n_bigtens 2
328#endif
329
330#ifndef LONG_MAX
331#define LONG_MAX 2147483647
332#endif
333
334#else /* ifndef Bad_float_h */
335#include "float.h"
336#endif /* Bad_float_h */
337
338#ifdef IEEE_Arith
339#define Scale_Bit 0x10
340#define n_bigtens 5
341#endif
342
343#ifdef IBM
344#define n_bigtens 3
345#endif
346
347#ifdef VAX
348#define n_bigtens 2
349#endif
350
351#ifndef __MATH_H__
352#include "math.h"
353#endif
354
355#ifdef __cplusplus
356extern "C" {
357#endif
358
359#if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1
360Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined.
361#endif
362
363typedef union { double d; ULong L[2]; } U;
364
9385eb3d 365#ifdef IEEE_8087
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366#define word0(x) (x)->L[1]
367#define word1(x) (x)->L[0]
9385eb3d 368#else
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369#define word0(x) (x)->L[0]
370#define word1(x) (x)->L[1]
9385eb3d 371#endif
1f2f436a 372#define dval(x) (x)->d
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373
374/* The following definition of Storeinc is appropriate for MIPS processors.
375 * An alternative that might be better on some machines is
376 * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
377 */
378#if defined(IEEE_8087) + defined(VAX)
379#define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \
380((unsigned short *)a)[0] = (unsigned short)c, a++)
381#else
382#define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \
383((unsigned short *)a)[1] = (unsigned short)c, a++)
384#endif
385
386/* #define P DBL_MANT_DIG */
387/* Ten_pmax = floor(P*log(2)/log(5)) */
388/* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
389/* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
390/* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
391
392#ifdef IEEE_Arith
393#define Exp_shift 20
394#define Exp_shift1 20
395#define Exp_msk1 0x100000
396#define Exp_msk11 0x100000
397#define Exp_mask 0x7ff00000
398#define P 53
399#define Bias 1023
400#define Emin (-1022)
401#define Exp_1 0x3ff00000
402#define Exp_11 0x3ff00000
403#define Ebits 11
404#define Frac_mask 0xfffff
405#define Frac_mask1 0xfffff
406#define Ten_pmax 22
407#define Bletch 0x10
408#define Bndry_mask 0xfffff
409#define Bndry_mask1 0xfffff
410#define LSB 1
411#define Sign_bit 0x80000000
412#define Log2P 1
413#define Tiny0 0
414#define Tiny1 1
415#define Quick_max 14
416#define Int_max 14
417
418#ifndef Flt_Rounds
419#ifdef FLT_ROUNDS
420#define Flt_Rounds FLT_ROUNDS
421#else
422#define Flt_Rounds 1
423#endif
424#endif /*Flt_Rounds*/
425
426#else /* ifndef IEEE_Arith */
427#undef Sudden_Underflow
428#define Sudden_Underflow
429#ifdef IBM
430#undef Flt_Rounds
431#define Flt_Rounds 0
432#define Exp_shift 24
433#define Exp_shift1 24
434#define Exp_msk1 0x1000000
435#define Exp_msk11 0x1000000
436#define Exp_mask 0x7f000000
437#define P 14
438#define Bias 65
439#define Exp_1 0x41000000
440#define Exp_11 0x41000000
441#define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */
442#define Frac_mask 0xffffff
443#define Frac_mask1 0xffffff
444#define Bletch 4
445#define Ten_pmax 22
446#define Bndry_mask 0xefffff
447#define Bndry_mask1 0xffffff
448#define LSB 1
449#define Sign_bit 0x80000000
450#define Log2P 4
451#define Tiny0 0x100000
452#define Tiny1 0
453#define Quick_max 14
454#define Int_max 15
455#else /* VAX */
456#undef Flt_Rounds
457#define Flt_Rounds 1
458#define Exp_shift 23
459#define Exp_shift1 7
460#define Exp_msk1 0x80
461#define Exp_msk11 0x800000
462#define Exp_mask 0x7f80
463#define P 56
464#define Bias 129
465#define Exp_1 0x40800000
466#define Exp_11 0x4080
467#define Ebits 8
468#define Frac_mask 0x7fffff
469#define Frac_mask1 0xffff007f
470#define Ten_pmax 24
471#define Bletch 2
472#define Bndry_mask 0xffff007f
473#define Bndry_mask1 0xffff007f
474#define LSB 0x10000
475#define Sign_bit 0x8000
476#define Log2P 1
477#define Tiny0 0x80
478#define Tiny1 0
479#define Quick_max 15
480#define Int_max 15
481#endif /* IBM, VAX */
482#endif /* IEEE_Arith */
483
484#ifndef IEEE_Arith
485#define ROUND_BIASED
486#endif
487
488#ifdef RND_PRODQUOT
489#define rounded_product(a,b) a = rnd_prod(a, b)
490#define rounded_quotient(a,b) a = rnd_quot(a, b)
491#ifdef KR_headers
492extern double rnd_prod(), rnd_quot();
493#else
494extern double rnd_prod(double, double), rnd_quot(double, double);
495#endif
496#else
497#define rounded_product(a,b) a *= b
498#define rounded_quotient(a,b) a /= b
499#endif
500
501#define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
502#define Big1 0xffffffff
503
504#undef Pack_16
505#ifndef Pack_32
506#define Pack_32
507#endif
508
509#ifdef NO_LONG_LONG
510#undef ULLong
511#ifdef Just_16
512#undef Pack_32
513#define Pack_16
514/* When Pack_32 is not defined, we store 16 bits per 32-bit Long.
515 * This makes some inner loops simpler and sometimes saves work
516 * during multiplications, but it often seems to make things slightly
517 * slower. Hence the default is now to store 32 bits per Long.
518 */
519#endif
520#else /* long long available */
521#ifndef Llong
522#define Llong long long
523#endif
524#ifndef ULLong
525#define ULLong unsigned Llong
526#endif
527#endif /* NO_LONG_LONG */
528
529#ifdef Pack_32
530#define ULbits 32
531#define kshift 5
532#define kmask 31
533#define ALL_ON 0xffffffff
534#else
535#define ULbits 16
536#define kshift 4
537#define kmask 15
538#define ALL_ON 0xffff
539#endif
540
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541#define MULTIPLE_THREADS
542extern spinlock_t __gdtoa_locks[2];
543#define ACQUIRE_DTOA_LOCK(n) do { \
544 if (__isthreaded) _SPINLOCK(&__gdtoa_locks[n]); \
545} while(0)
546#define FREE_DTOA_LOCK(n) do { \
547 if (__isthreaded) _SPINUNLOCK(&__gdtoa_locks[n]); \
548} while(0)
9385eb3d 549
1f2f436a 550#define Kmax 9
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551
552 struct
553Bigint {
554 struct Bigint *next;
555 int k, maxwds, sign, wds;
556 ULong x[1];
557 };
558
559 typedef struct Bigint Bigint;
560
561#ifdef NO_STRING_H
562#ifdef DECLARE_SIZE_T
563typedef unsigned int size_t;
564#endif
565extern void memcpy_D2A ANSI((void*, const void*, size_t));
566#define Bcopy(x,y) memcpy_D2A(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
567#else /* !NO_STRING_H */
568#define Bcopy(x,y) memcpy(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
569#endif /* NO_STRING_H */
570
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571 extern char *dtoa_result;
572 extern CONST double bigtens[], tens[], tinytens[];
6465356a 573 extern CONST unsigned char hexdig[];
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574
575 extern Bigint *Balloc ANSI((int));
576 extern void Bfree ANSI((Bigint*));
577 extern void ULtof ANSI((ULong*, ULong*, Long, int));
578 extern void ULtod ANSI((ULong*, ULong*, Long, int));
579 extern void ULtodd ANSI((ULong*, ULong*, Long, int));
580 extern void ULtoQ ANSI((ULong*, ULong*, Long, int));
581 extern void ULtox ANSI((UShort*, ULong*, Long, int));
582 extern void ULtoxL ANSI((ULong*, ULong*, Long, int));
583 extern ULong any_on ANSI((Bigint*, int));
584 extern double b2d ANSI((Bigint*, int*));
585 extern int cmp ANSI((Bigint*, Bigint*));
586 extern void copybits ANSI((ULong*, int, Bigint*));
587 extern Bigint *d2b ANSI((double, int*, int*));
34e8f829 588 extern void decrement ANSI((Bigint*));
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589 extern Bigint *diff ANSI((Bigint*, Bigint*));
590 extern char *dtoa ANSI((double d, int mode, int ndigits,
591 int *decpt, int *sign, char **rve));
34e8f829 592 extern char *g__fmt ANSI((char*, char*, char*, int, ULong, size_t));
6465356a 593 extern int gethex ANSI((CONST char**, CONST FPI*, Long*, Bigint**, int, locale_t));
9385eb3d 594 extern void hexdig_init_D2A(Void);
6465356a 595 extern int hexnan ANSI((CONST char**, CONST FPI*, ULong*));
3d9156a7 596 extern int hi0bits_D2A ANSI((ULong));
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597 extern Bigint *i2b ANSI((int));
598 extern Bigint *increment ANSI((Bigint*));
599 extern int lo0bits ANSI((ULong*));
600 extern Bigint *lshift ANSI((Bigint*, int));
601 extern int match ANSI((CONST char**, char*));
602 extern Bigint *mult ANSI((Bigint*, Bigint*));
603 extern Bigint *multadd ANSI((Bigint*, int, int));
604 extern char *nrv_alloc ANSI((char*, char **, int));
605 extern Bigint *pow5mult ANSI((Bigint*, int));
606 extern int quorem ANSI((Bigint*, Bigint*));
607 extern double ratio ANSI((Bigint*, Bigint*));
608 extern void rshift ANSI((Bigint*, int));
609 extern char *rv_alloc ANSI((int));
1f2f436a 610 extern Bigint *s2b ANSI((CONST char*, int, int, ULong, int));
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611 extern Bigint *set_ones ANSI((Bigint*, int));
612 extern char *strcp ANSI((char*, const char*));
9385eb3d 613 extern int strtoIg ANSI((CONST char*, char**, FPI*, Long*, Bigint**, int*));
9385eb3d 614 extern double strtod ANSI((const char *s00, char **se));
ad3c9f2a 615 extern double strtod_l ANSI((const char *s00, char **se, locale_t));
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616 extern Bigint *sum ANSI((Bigint*, Bigint*));
617 extern int trailz ANSI((Bigint*));
1f2f436a 618 extern double ulp ANSI((U*));
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619
620#ifdef __cplusplus
621}
622#endif
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623/*
624 * NAN_WORD0 and NAN_WORD1 are only referenced in strtod.c. Prior to
625 * 20050115, they used to be hard-wired here (to 0x7ff80000 and 0,
626 * respectively), but now are determined by compiling and running
627 * qnan.c to generate gd_qnan.h, which specifies d_QNAN0 and d_QNAN1.
628 * Formerly gdtoaimp.h recommended supplying suitable -DNAN_WORD0=...
629 * and -DNAN_WORD1=... values if necessary. This should still work.
630 * (On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.)
631 */
9385eb3d 632#ifdef IEEE_Arith
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633#ifndef NO_INFNAN_CHECK
634#undef INFNAN_CHECK
635#define INFNAN_CHECK
636#endif
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637#ifdef IEEE_MC68k
638#define _0 0
639#define _1 1
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640#ifndef NAN_WORD0
641#define NAN_WORD0 d_QNAN0
642#endif
643#ifndef NAN_WORD1
644#define NAN_WORD1 d_QNAN1
645#endif
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646#else
647#define _0 1
648#define _1 0
9385eb3d 649#ifndef NAN_WORD0
3d9156a7 650#define NAN_WORD0 d_QNAN1
9385eb3d 651#endif
9385eb3d 652#ifndef NAN_WORD1
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653#define NAN_WORD1 d_QNAN0
654#endif
655#endif
656#else
657#undef INFNAN_CHECK
9385eb3d 658#endif
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659
660#undef SI
661#ifdef Sudden_Underflow
662#define SI 1
663#else
664#define SI 0
665#endif
666
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667/*
668 * For very large strings, strtod and family might exhaust memory in tight
669 * memory conditions (especially in 32-bits). Such large strings could also
670 * tie up a CPU for minutes at a time. Either can be considered a denial-of-
671 * service vunerability.
672 *
673 * To fix, we limit the string size to the maximum we need to calculate the
674 * rounding point correctly. The longest string corresponding to the exact
675 * value of a floating point number occuring at 1.f...f p^-n, where n is
676 * the (absolute value of the) smallest exponent for a normalize number.
677 *
678 * To calculate this number of decimal digits, we use the formula:
679 *
680 * (n + m) - int(n * log10(2)) + 3
681 *
682 * where m is the number of bits in the f...f fraction. This is the number
683 * of decimal digits for the least significant bit minus the number of leading
684 * zeros for the most significant bit (the '1'), plus a few to compensate for
685 * an extra digits due to the full 1.f...f value, an extra digit for the
686 * mid-way point for rounding and an extra guard digit.
687 *
688 * Using the approximation log10(2) ~ 1233 / (2^12), converting to the fpi.emin
689 * and fpi.nbits values, we get:
690 *
691 * -fpi.emin -((1233 * (-fpi.nbits - fpi.emin)) >> 12) + 3
692 *
693 * Finally, we add an extra digit, either '1' or '0', to represent whether
694 * to-be-truncated digits contain a non-zero digit, or are all zeros,
695 * respectively.
696 *
697 * The truncated string is allocated on the heap, so code using
698 * TRUNCATE_DIGITS() will need to free that space when no longer needed.
699 * Pass a char * as the second argument, initialized to NULL; if its value
700 * becomes non-NULL, memory was allocated.
701 */
702#define LOG2NUM 1233
703#define LOG2DENOMSHIFT 12
704#define TRUNCATEDIGITS(_nbits, _emin) (-(_emin) - ((LOG2NUM * (-(_nbits) - (_emin))) >> LOG2DENOMSHIFT) + 3)
705
706#define TRUNCATE_DIGITS(_s0, _temp, _nd, _nd0, _nf, _nbits, _emin, _dplen) \
707{ \
708 int _maxdigits = TRUNCATEDIGITS((_nbits), (_emin)); \
709 if ((_nd) > _maxdigits && \
710 ((_temp) = MALLOC(_maxdigits + (_dplen) + 2)) != NULL) { \
711 char *_tp = (_temp) + _maxdigits; \
712 if ((_nd0) >= _maxdigits) { \
713 memcpy((_temp), (_s0), _maxdigits); \
714 if ((_nd) > (_nd0)) *_tp++ = '1'; \
715 else { \
716 const char *_q = (_s0) + _maxdigits; \
717 int _n = (_nd0) - _maxdigits; \
718 for(; _n > 0 && *_q == '0'; _n--, _q++) {} \
719 *_tp++ = _n > 0 ? '1' : '0'; \
720 } \
721 (_nf) = -((_nd0) - (_maxdigits + 1)); \
722 (_nd0) = _maxdigits + 1; \
723 } \
724 else if ((_nd0) == 0) { \
725 memcpy((_temp), (_s0), _maxdigits); \
726 *_tp++ = '1'; \
727 (_nf) -= ((_nd) - (_maxdigits + 1)); \
728 } \
729 else { \
730 memcpy((_temp), (_s0), _maxdigits + (_dplen)); \
731 _tp += (_dplen); \
732 *_tp++ = '1'; \
733 (_nf) = (_maxdigits + 1) - (_nd0); \
734 } \
735 *_tp = 0; \
736 (_nd) = _maxdigits + 1; \
737 (_s0) = (_temp); \
738 } \
739 }
740
9385eb3d 741#endif /* GDTOAIMP_H_INCLUDED */