xref: /netbsd-src/lib/libc/gdtoa/gdtoaimp.h (revision 63d4abf06d37aace2f9e41a494102a64fe3abddb)
1 /* $NetBSD: gdtoaimp.h,v 1.7 2009/05/07 20:31:44 christos Exp $ */
2 
3 /****************************************************************
4 
5 The author of this software is David M. Gay.
6 
7 Copyright (C) 1998-2000 by Lucent Technologies
8 All Rights Reserved
9 
10 Permission to use, copy, modify, and distribute this software and
11 its documentation for any purpose and without fee is hereby
12 granted, provided that the above copyright notice appear in all
13 copies and that both that the copyright notice and this
14 permission notice and warranty disclaimer appear in supporting
15 documentation, and that the name of Lucent or any of its entities
16 not be used in advertising or publicity pertaining to
17 distribution of the software without specific, written prior
18 permission.
19 
20 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
22 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
23 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
24 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
25 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
26 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
27 THIS SOFTWARE.
28 
29 ****************************************************************/
30 
31 /* This is a variation on dtoa.c that converts arbitary binary
32    floating-point formats to and from decimal notation.  It uses
33    double-precision arithmetic internally, so there are still
34    various #ifdefs that adapt the calculations to the native
35    double-precision arithmetic (any of IEEE, VAX D_floating,
36    or IBM mainframe arithmetic).
37 
38    Please send bug reports to David M. Gay (dmg at acm dot org,
39    with " at " changed at "@" and " dot " changed to ".").
40  */
41 
42 /* On a machine with IEEE extended-precision registers, it is
43  * necessary to specify double-precision (53-bit) rounding precision
44  * before invoking strtod or dtoa.  If the machine uses (the equivalent
45  * of) Intel 80x87 arithmetic, the call
46  *	_control87(PC_53, MCW_PC);
47  * does this with many compilers.  Whether this or another call is
48  * appropriate depends on the compiler; for this to work, it may be
49  * necessary to #include "float.h" or another system-dependent header
50  * file.
51  */
52 
53 /* strtod for IEEE-, VAX-, and IBM-arithmetic machines.
54  *
55  * This strtod returns a nearest machine number to the input decimal
56  * string (or sets errno to ERANGE).  With IEEE arithmetic, ties are
57  * broken by the IEEE round-even rule.  Otherwise ties are broken by
58  * biased rounding (add half and chop).
59  *
60  * Inspired loosely by William D. Clinger's paper "How to Read Floating
61  * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 112-126].
62  *
63  * Modifications:
64  *
65  *	1. We only require IEEE, IBM, or VAX double-precision
66  *		arithmetic (not IEEE double-extended).
67  *	2. We get by with floating-point arithmetic in a case that
68  *		Clinger missed -- when we're computing d * 10^n
69  *		for a small integer d and the integer n is not too
70  *		much larger than 22 (the maximum integer k for which
71  *		we can represent 10^k exactly), we may be able to
72  *		compute (d*10^k) * 10^(e-k) with just one roundoff.
73  *	3. Rather than a bit-at-a-time adjustment of the binary
74  *		result in the hard case, we use floating-point
75  *		arithmetic to determine the adjustment to within
76  *		one bit; only in really hard cases do we need to
77  *		compute a second residual.
78  *	4. Because of 3., we don't need a large table of powers of 10
79  *		for ten-to-e (just some small tables, e.g. of 10^k
80  *		for 0 <= k <= 22).
81  */
82 
83 /*
84  * #define IEEE_LITTLE_ENDIAN for IEEE-arithmetic machines where the least
85  *	significant byte has the lowest address.
86  * #define IEEE_BIG_ENDIAN for IEEE-arithmetic machines where the most
87  *	significant byte has the lowest address.
88  * #define Long int on machines with 32-bit ints and 64-bit longs.
89  * #define Sudden_Underflow for IEEE-format machines without gradual
90  *	underflow (i.e., that flush to zero on underflow).
91  * #define IBM for IBM mainframe-style floating-point arithmetic.
92  * #define VAX for VAX-style floating-point arithmetic (D_floating).
93  * #define No_leftright to omit left-right logic in fast floating-point
94  *	computation of dtoa.
95  * #define Check_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3.
96  * #define RND_PRODQUOT to use rnd_prod and rnd_quot (assembly routines
97  *	that use extended-precision instructions to compute rounded
98  *	products and quotients) with IBM.
99  * #define ROUND_BIASED for IEEE-format with biased rounding.
100  * #define Inaccurate_Divide for IEEE-format with correctly rounded
101  *	products but inaccurate quotients, e.g., for Intel i860.
102  * #define NO_LONG_LONG on machines that do not have a "long long"
103  *	integer type (of >= 64 bits).  On such machines, you can
104  *	#define Just_16 to store 16 bits per 32-bit Long when doing
105  *	high-precision integer arithmetic.  Whether this speeds things
106  *	up or slows things down depends on the machine and the number
107  *	being converted.  If long long is available and the name is
108  *	something other than "long long", #define Llong to be the name,
109  *	and if "unsigned Llong" does not work as an unsigned version of
110  *	Llong, #define #ULLong to be the corresponding unsigned type.
111  * #define KR_headers for old-style C function headers.
112  * #define Bad_float_h if your system lacks a float.h or if it does not
113  *	define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP,
114  *	FLT_RADIX, FLT_ROUNDS, and DBL_MAX.
115  * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n)
116  *	if memory is available and otherwise does something you deem
117  *	appropriate.  If MALLOC is undefined, malloc will be invoked
118  *	directly -- and assumed always to succeed.
119  * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
120  *	memory allocations from a private pool of memory when possible.
121  *	When used, the private pool is PRIVATE_MEM bytes long:  2304 bytes,
122  *	unless #defined to be a different length.  This default length
123  *	suffices to get rid of MALLOC calls except for unusual cases,
124  *	such as decimal-to-binary conversion of a very long string of
125  *	digits.  When converting IEEE double precision values, the
126  *	longest string gdtoa can return is about 751 bytes long.  For
127  *	conversions by strtod of strings of 800 digits and all gdtoa
128  *	conversions of IEEE doubles in single-threaded executions with
129  *	8-byte pointers, PRIVATE_MEM >= 7400 appears to suffice; with
130  *	4-byte pointers, PRIVATE_MEM >= 7112 appears adequate.
131  * #define INFNAN_CHECK on IEEE systems to cause strtod to check for
132  *	Infinity and NaN (case insensitively).
133  *	When INFNAN_CHECK is #defined and No_Hex_NaN is not #defined,
134  *	strtodg also accepts (case insensitively) strings of the form
135  *	NaN(x), where x is a string of hexadecimal digits and spaces;
136  *	if there is only one string of hexadecimal digits, it is taken
137  *	for the fraction bits of the resulting NaN; if there are two or
138  *	more strings of hexadecimal digits, each string is assigned
139  *	to the next available sequence of 32-bit words of fractions
140  *	bits (starting with the most significant), right-aligned in
141  *	each sequence.
142  * #define MULTIPLE_THREADS if the system offers preemptively scheduled
143  *	multiple threads.  In this case, you must provide (or suitably
144  *	#define) two locks, acquired by ACQUIRE_DTOA_LOCK(n) and freed
145  *	by FREE_DTOA_LOCK(n) for n = 0 or 1.  (The second lock, accessed
146  *	in pow5mult, ensures lazy evaluation of only one copy of high
147  *	powers of 5; omitting this lock would introduce a small
148  *	probability of wasting memory, but would otherwise be harmless.)
149  *	You must also invoke freedtoa(s) to free the value s returned by
150  *	dtoa.  You may do so whether or not MULTIPLE_THREADS is #defined.
151  * #define IMPRECISE_INEXACT if you do not care about the setting of
152  *	the STRTOG_Inexact bits in the special case of doing IEEE double
153  *	precision conversions (which could also be done by the strtog in
154  *	dtoa.c).
155  * #define NO_HEX_FP to disable recognition of C9x's hexadecimal
156  *	floating-point constants.
157  * #define -DNO_ERRNO to suppress setting errno (in strtod.c and
158  *	strtodg.c).
159  * #define NO_STRING_H to use private versions of memcpy.
160  *	On some K&R systems, it may also be necessary to
161  *	#define DECLARE_SIZE_T in this case.
162  * #define YES_ALIAS to permit aliasing certain double values with
163  *	arrays of ULongs.  This leads to slightly better code with
164  *	some compilers and was always used prior to 19990916, but it
165  *	is not strictly legal and can cause trouble with aggressively
166  *	optimizing compilers (e.g., gcc 2.95.1 under -O2).
167  * #define USE_LOCALE to use the current locale's decimal_point value.
168  */
169 
170 /* #define IEEE_{BIG,LITTLE}_ENDIAN in ${ARCHDIR}/gdtoa/arith.h */
171 
172 #include <stdint.h>
173 #define Short   int16_t
174 #define UShort uint16_t
175 #define Long    int32_t
176 #define ULong  uint32_t
177 #define LLong   int64_t
178 #define ULLong uint64_t
179 
180 #define INFNAN_CHECK
181 #ifdef _REENTRANT
182 #define MULTIPLE_THREADS
183 #endif
184 #define USE_LOCALE
185 
186 #ifndef GDTOAIMP_H_INCLUDED
187 #define GDTOAIMP_H_INCLUDED
188 #include "gdtoa.h"
189 #include "gd_qnan.h"
190 
191 #ifdef DEBUG
192 #include "stdio.h"
193 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
194 #endif
195 
196 #include "stdlib.h"
197 #include "string.h"
198 
199 #ifdef KR_headers
200 #define Char char
201 #else
202 #define Char void
203 #endif
204 
205 #ifdef MALLOC
206 extern Char *MALLOC ANSI((size_t));
207 #else
208 #define MALLOC malloc
209 #endif
210 
211 #undef IEEE_Arith
212 #undef Avoid_Underflow
213 #ifdef IEEE_BIG_ENDIAN
214 #define IEEE_Arith
215 #endif
216 #ifdef IEEE_LITTLE_ENDIAN
217 #define IEEE_Arith
218 #endif
219 
220 #include "errno.h"
221 #ifdef Bad_float_h
222 
223 #ifdef IEEE_Arith
224 #define DBL_DIG 15
225 #define DBL_MAX_10_EXP 308
226 #define DBL_MAX_EXP 1024
227 #define FLT_RADIX 2
228 #define DBL_MAX 1.7976931348623157e+308
229 #endif
230 
231 #ifdef IBM
232 #define DBL_DIG 16
233 #define DBL_MAX_10_EXP 75
234 #define DBL_MAX_EXP 63
235 #define FLT_RADIX 16
236 #define DBL_MAX 7.2370055773322621e+75
237 #endif
238 
239 #ifdef VAX
240 #define DBL_DIG 16
241 #define DBL_MAX_10_EXP 38
242 #define DBL_MAX_EXP 127
243 #define FLT_RADIX 2
244 #define DBL_MAX 1.7014118346046923e+38
245 #define n_bigtens 2
246 #endif
247 
248 #ifndef LONG_MAX
249 #define LONG_MAX 2147483647
250 #endif
251 
252 #else /* ifndef Bad_float_h */
253 #include "float.h"
254 #endif /* Bad_float_h */
255 
256 #ifdef IEEE_Arith
257 #define Scale_Bit 0x10
258 #define n_bigtens 5
259 #endif
260 
261 #ifdef IBM
262 #define n_bigtens 3
263 #endif
264 
265 #ifdef VAX
266 #define n_bigtens 2
267 #endif
268 
269 #include "math.h"
270 
271 #ifdef __cplusplus
272 extern "C" {
273 #endif
274 
275 #if defined(IEEE_LITTLE_ENDIAN) + defined(IEEE_BIG_ENDIAN) + defined(VAX) + defined(IBM) != 1
276 Exactly one of IEEE_LITTLE_ENDIAN, IEEE_BIG_ENDIAN, VAX, or IBM should be defined.
277 #endif
278 
279 typedef union { double d; ULong L[2]; } U;
280 
281 #ifdef YES_ALIAS
282 #define dval(x) x
283 #ifdef IEEE_LITTLE_ENDIAN
284 #define word0(x) ((ULong *)&x)[1]
285 #define word1(x) ((ULong *)&x)[0]
286 #else
287 #define word0(x) ((ULong *)&x)[0]
288 #define word1(x) ((ULong *)&x)[1]
289 #endif
290 #else /* !YES_ALIAS */
291 #ifdef IEEE_LITTLE_ENDIAN
292 #define word0(x) ( /* LINTED */ (U*)&x)->L[1]
293 #define word1(x) ( /* LINTED */ (U*)&x)->L[0]
294 #else
295 #define word0(x) ( /* LINTED */ (U*)&x)->L[0]
296 #define word1(x) ( /* LINTED */ (U*)&x)->L[1]
297 #endif
298 #define dval(x) ( /* LINTED */ (U*)&x)->d
299 #endif /* YES_ALIAS */
300 
301 /* The following definition of Storeinc is appropriate for MIPS processors.
302  * An alternative that might be better on some machines is
303  * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
304  */
305 #if defined(IEEE_LITTLE_ENDIAN) + defined(VAX)
306 #define Storeinc(a,b,c) \
307  (((unsigned short *)(void *)a)[1] = (unsigned short)b, \
308   ((unsigned short *)(void *)a)[0] = (unsigned short)c, \
309   a++)
310 #else
311 #define Storeinc(a,b,c) \
312  (((unsigned short *)(void *)a)[0] = (unsigned short)b, \
313   ((unsigned short *)(void *)a)[1] = (unsigned short)c, \
314   a++)
315 #endif
316 
317 /* #define P DBL_MANT_DIG */
318 /* Ten_pmax = floor(P*log(2)/log(5)) */
319 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
320 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
321 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
322 
323 #ifdef IEEE_Arith
324 #define Exp_shift  20
325 #define Exp_shift1 20
326 #define Exp_msk1    0x100000
327 #define Exp_msk11   0x100000
328 #define Exp_mask  0x7ff00000
329 #define P 53
330 #define Bias 1023
331 #define Emin (-1022)
332 #define Exp_1  0x3ff00000
333 #define Exp_11 0x3ff00000
334 #define Ebits 11
335 #define Frac_mask  0xfffff
336 #define Frac_mask1 0xfffff
337 #define Ten_pmax 22
338 #define Bletch 0x10
339 #define Bndry_mask  0xfffff
340 #define Bndry_mask1 0xfffff
341 #define LSB 1
342 #define Sign_bit 0x80000000
343 #define Log2P 1
344 #define Tiny0 0
345 #define Tiny1 1
346 #define Quick_max 14
347 #define Int_max 14
348 
349 #ifndef Flt_Rounds
350 #ifdef FLT_ROUNDS
351 #define Flt_Rounds FLT_ROUNDS
352 #else
353 #define Flt_Rounds 1
354 #endif
355 #endif /*Flt_Rounds*/
356 
357 #else /* ifndef IEEE_Arith */
358 #undef  Sudden_Underflow
359 #define Sudden_Underflow
360 #ifdef IBM
361 #undef Flt_Rounds
362 #define Flt_Rounds 0
363 #define Exp_shift  24
364 #define Exp_shift1 24
365 #define Exp_msk1   0x1000000
366 #define Exp_msk11  0x1000000
367 #define Exp_mask  0x7f000000
368 #define P 14
369 #define Bias 65
370 #define Exp_1  0x41000000
371 #define Exp_11 0x41000000
372 #define Ebits 8	/* exponent has 7 bits, but 8 is the right value in b2d */
373 #define Frac_mask  0xffffff
374 #define Frac_mask1 0xffffff
375 #define Bletch 4
376 #define Ten_pmax 22
377 #define Bndry_mask  0xefffff
378 #define Bndry_mask1 0xffffff
379 #define LSB 1
380 #define Sign_bit 0x80000000
381 #define Log2P 4
382 #define Tiny0 0x100000
383 #define Tiny1 0
384 #define Quick_max 14
385 #define Int_max 15
386 #else /* VAX */
387 #undef Flt_Rounds
388 #define Flt_Rounds 1
389 #define Exp_shift  23
390 #define Exp_shift1 7
391 #define Exp_msk1    0x80
392 #define Exp_msk11   0x800000
393 #define Exp_mask  0x7f80
394 #define P 56
395 #define Bias 129
396 #define Exp_1  0x40800000
397 #define Exp_11 0x4080
398 #define Ebits 8
399 #define Frac_mask  0x7fffff
400 #define Frac_mask1 0xffff007f
401 #define Ten_pmax 24
402 #define Bletch 2
403 #define Bndry_mask  0xffff007f
404 #define Bndry_mask1 0xffff007f
405 #define LSB 0x10000
406 #define Sign_bit 0x8000
407 #define Log2P 1
408 #define Tiny0 0x80
409 #define Tiny1 0
410 #define Quick_max 15
411 #define Int_max 15
412 #endif /* IBM, VAX */
413 #endif /* IEEE_Arith */
414 
415 #ifndef IEEE_Arith
416 #define ROUND_BIASED
417 #endif
418 
419 #ifdef RND_PRODQUOT
420 #define rounded_product(a,b) a = rnd_prod(a, b)
421 #define rounded_quotient(a,b) a = rnd_quot(a, b)
422 #ifdef KR_headers
423 extern double rnd_prod(), rnd_quot();
424 #else
425 extern double rnd_prod(double, double), rnd_quot(double, double);
426 #endif
427 #else
428 #define rounded_product(a,b) a *= b
429 #define rounded_quotient(a,b) a /= b
430 #endif
431 
432 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
433 #define Big1 0xffffffff
434 
435 #undef  Pack_16
436 #ifndef Pack_32
437 #define Pack_32
438 #endif
439 
440 #ifdef NO_LONG_LONG
441 #undef ULLong
442 #ifdef Just_16
443 #undef Pack_32
444 #define Pack_16
445 /* When Pack_32 is not defined, we store 16 bits per 32-bit Long.
446  * This makes some inner loops simpler and sometimes saves work
447  * during multiplications, but it often seems to make things slightly
448  * slower.  Hence the default is now to store 32 bits per Long.
449  */
450 #endif
451 #else	/* long long available */
452 #ifndef Llong
453 #define Llong long long
454 #endif
455 #ifndef ULLong
456 #define ULLong unsigned Llong
457 #endif
458 #endif /* NO_LONG_LONG */
459 
460 #ifdef Pack_32
461 #define ULbits 32
462 #define kshift 5
463 #define kmask 31
464 #define ALL_ON 0xffffffff
465 #else
466 #define ULbits 16
467 #define kshift 4
468 #define kmask 15
469 #define ALL_ON 0xffff
470 #endif
471 
472 #ifndef MULTIPLE_THREADS
473 #define ACQUIRE_DTOA_LOCK(n)	/*nothing*/
474 #define FREE_DTOA_LOCK(n)	/*nothing*/
475 #else
476 #include "reentrant.h"
477 
478 extern mutex_t __gdtoa_locks[2];
479 
480 #define ACQUIRE_DTOA_LOCK(n)	\
481 	do {							\
482 		if (__isthreaded)				\
483 			mutex_lock(&__gdtoa_locks[n]);		\
484 	} while (/* CONSTCOND */ 0)
485 #define FREE_DTOA_LOCK(n)	\
486 	do {							\
487 		if (__isthreaded)				\
488 			mutex_unlock(&__gdtoa_locks[n]);	\
489 	} while (/* CONSTCOND */ 0)
490 #endif
491 
492 #define Kmax (sizeof(size_t) << 3)
493 
494  struct
495 Bigint {
496 	struct Bigint *next;
497 	int k, maxwds, sign, wds;
498 	ULong x[1];
499 	};
500 
501  typedef struct Bigint Bigint;
502 
503 #ifdef NO_STRING_H
504 #ifdef DECLARE_SIZE_T
505 typedef unsigned int size_t;
506 #endif
507 extern void memcpy_D2A ANSI((void*, const void*, size_t));
508 #define Bcopy(x,y) memcpy_D2A(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
509 #else /* !NO_STRING_H */
510 #define Bcopy(x,y) memcpy(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
511 #endif /* NO_STRING_H */
512 
513 #define Balloc		__Balloc_D2A
514 #define Bfree		__Bfree_D2A
515 #define ULtoQ		__ULtoQ_D2A
516 #define ULtof		__ULtof_D2A
517 #define ULtod		__ULtod_D2A
518 #define ULtodd		__ULtodd_D2A
519 #define ULtox		__ULtox_D2A
520 #define ULtoxL		__ULtoxL_D2A
521 #define any_on 		__any_on_D2A
522 #define b2d 		__b2d_D2A
523 #define bigtens 	__bigtens_D2A
524 #define cmp 		__cmp_D2A
525 #define copybits 	__copybits_D2A
526 #define d2b 		__d2b_D2A
527 #define decrement 	__decrement_D2A
528 #define diff 		__diff_D2A
529 #define dtoa_result 	__dtoa_result_D2A
530 #define g__fmt 		__g__fmt_D2A
531 #define gethex 		__gethex_D2A
532 #define hexdig 		__hexdig_D2A
533 #define hexdig_init_D2A	__hexdig_init_D2A
534 #define hexnan		__hexnan_D2A
535 #define hi0bits		__hi0bits_D2A
536 #define hi0bits_D2A	__hi0bits_D2A
537 #define i2b		__i2b_D2A
538 #define increment	__increment_D2A
539 #define lo0bits		__lo0bits_D2A
540 #define lshift		__lshift_D2A
541 #define match		__match_D2A
542 #define mult		__mult_D2A
543 #define multadd		__multadd_D2A
544 #define nrv_alloc	__nrv_alloc_D2A
545 #define pow5mult	__pow5mult_D2A
546 #define quorem		__quorem_D2A
547 #define ratio		__ratio_D2A
548 #define rshift		__rshift_D2A
549 #define rv_alloc	__rv_alloc_D2A
550 #define s2b		__s2b_D2A
551 #define set_ones	__set_ones_D2A
552 #define strcp		__strcp_D2A
553 #define strcp_D2A	__strcp_D2A
554 #define strtoIg		__strtoIg_D2A
555 #define sum		__sum_D2A
556 #define tens		__tens_D2A
557 #define tinytens	__tinytens_D2A
558 #define tinytens	__tinytens_D2A
559 #define trailz		__trailz_D2A
560 #define ulp		__ulp_D2A
561 
562  extern char *dtoa_result;
563  extern CONST double bigtens[], tens[], tinytens[];
564  extern unsigned char hexdig[];
565 
566  extern Bigint *Balloc ANSI((int));
567  extern void Bfree ANSI((Bigint*));
568  extern void ULtof ANSI((ULong*, ULong*, Long, int));
569  extern void ULtod ANSI((ULong*, ULong*, Long, int));
570  extern void ULtodd ANSI((ULong*, ULong*, Long, int));
571  extern void ULtoQ ANSI((ULong*, ULong*, Long, int));
572  extern void ULtox ANSI((UShort*, ULong*, Long, int));
573  extern void ULtoxL ANSI((ULong*, ULong*, Long, int));
574  extern ULong any_on ANSI((Bigint*, int));
575  extern double b2d ANSI((Bigint*, int*));
576  extern int cmp ANSI((Bigint*, Bigint*));
577  extern void copybits ANSI((ULong*, int, Bigint*));
578  extern Bigint *d2b ANSI((double, int*, int*));
579  extern int decrement ANSI((Bigint*));
580  extern Bigint *diff ANSI((Bigint*, Bigint*));
581  extern char *dtoa ANSI((double d, int mode, int ndigits,
582 			int *decpt, int *sign, char **rve));
583  extern char *g__fmt ANSI((char*, char*, char*, int, ULong));
584  extern int gethex ANSI((CONST char**, CONST FPI*, Long*, Bigint**, int));
585  extern void hexdig_init_D2A(Void);
586  extern int hexnan ANSI((CONST char**, CONST FPI*, ULong*));
587  extern int hi0bits_D2A ANSI((ULong));
588  extern Bigint *i2b ANSI((int));
589  extern Bigint *increment ANSI((Bigint*));
590  extern int lo0bits ANSI((ULong*));
591  extern Bigint *lshift ANSI((Bigint*, int));
592  extern int match ANSI((CONST char**, CONST char*));
593  extern Bigint *mult ANSI((Bigint*, Bigint*));
594  extern Bigint *multadd ANSI((Bigint*, int, int));
595  extern char *nrv_alloc ANSI((CONST char*, char **, size_t));
596  extern Bigint *pow5mult ANSI((Bigint*, int));
597  extern int quorem ANSI((Bigint*, Bigint*));
598  extern double ratio ANSI((Bigint*, Bigint*));
599  extern void rshift ANSI((Bigint*, int));
600  extern char *rv_alloc ANSI((size_t));
601  extern Bigint *s2b ANSI((CONST char*, int, int, ULong));
602  extern Bigint *set_ones ANSI((Bigint*, int));
603  extern char *strcp ANSI((char*, const char*));
604  extern int strtoIg ANSI((CONST char*, char**, FPI*, Long*, Bigint**, int*));
605  extern double strtod ANSI((const char *s00, char **se));
606  extern Bigint *sum ANSI((Bigint*, Bigint*));
607  extern int trailz ANSI((CONST Bigint*));
608  extern double ulp ANSI((double));
609 
610 #ifdef __cplusplus
611 }
612 #endif
613 /*
614  * NAN_WORD0 and NAN_WORD1 are only referenced in strtod.c.  Prior to
615  * 20050115, they used to be hard-wired here (to 0x7ff80000 and 0,
616  * respectively), but now are determined by compiling and running
617  * qnan.c to generate gd_qnan.h, which specifies d_QNAN0 and d_QNAN1.
618  * Formerly gdtoaimp.h recommended supplying suitable -DNAN_WORD0=...
619  * and -DNAN_WORD1=...  values if necessary.  This should still work.
620  * (On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.)
621  */
622 #ifdef IEEE_Arith
623 #ifdef IEEE_BIG_ENDIAN
624 #define _0 0
625 #define _1 1
626 #ifndef NAN_WORD0
627 #define NAN_WORD0 d_QNAN0
628 #endif
629 #ifndef NAN_WORD1
630 #define NAN_WORD1 d_QNAN1
631 #endif
632 #else
633 #define _0 1
634 #define _1 0
635 #ifndef NAN_WORD0
636 #define NAN_WORD0 d_QNAN1
637 #endif
638 #ifndef NAN_WORD1
639 #define NAN_WORD1 d_QNAN0
640 #endif
641 #endif
642 #else
643 #undef INFNAN_CHECK
644 #endif
645 
646 #undef SI
647 #ifdef Sudden_Underflow
648 #define SI 1
649 #else
650 #define SI 0
651 #endif
652 
653 #endif /* GDTOAIMP_H_INCLUDED */
654