xref: /freebsd/contrib/gdtoa/gdtoaimp.h (revision c88250a57d53dba5de2e77508383019ff63e88b6)
1 /****************************************************************
2 
3 The author of this software is David M. Gay.
4 
5 Copyright (C) 1998-2000 by Lucent Technologies
6 All Rights Reserved
7 
8 Permission to use, copy, modify, and distribute this software and
9 its documentation for any purpose and without fee is hereby
10 granted, provided that the above copyright notice appear in all
11 copies and that both that the copyright notice and this
12 permission notice and warranty disclaimer appear in supporting
13 documentation, and that the name of Lucent or any of its entities
14 not be used in advertising or publicity pertaining to
15 distribution of the software without specific, written prior
16 permission.
17 
18 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
19 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
20 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
21 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
22 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
23 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
24 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
25 THIS SOFTWARE.
26 
27 ****************************************************************/
28 
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 
36    Please send bug reports to David M. Gay (dmg at acm dot org,
37    with " at " changed at "@" and " dot " changed to ".").
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
59  * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 112-126].
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
116  *	directly -- and assumed always to succeed.
117  * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
118  *	memory allocations from a private pool of memory when possible.
119  *	When used, the private pool is PRIVATE_MEM bytes long:  2304 bytes,
120  *	unless #defined to be a different length.  This default length
121  *	suffices to get rid of MALLOC calls except for unusual cases,
122  *	such as decimal-to-binary conversion of a very long string of
123  *	digits.  When converting IEEE double precision values, the
124  *	longest string gdtoa can return is about 751 bytes long.  For
125  *	conversions by strtod of strings of 800 digits and all gdtoa
126  *	conversions of IEEE doubles in single-threaded executions with
127  *	8-byte pointers, PRIVATE_MEM >= 7400 appears to suffice; with
128  *	4-byte pointers, PRIVATE_MEM >= 7112 appears adequate.
129  * #define INFNAN_CHECK on IEEE systems to cause strtod to check for
130  *	Infinity and NaN (case insensitively).
131  *	When INFNAN_CHECK is #defined and No_Hex_NaN is not #defined,
132  *	strtodg also accepts (case insensitively) strings of the form
133  *	NaN(x), where x is a string of hexadecimal digits and spaces;
134  *	if there is only one string of hexadecimal digits, it is taken
135  *	for the fraction bits of the resulting NaN; if there are two or
136  *	more strings of hexadecimal digits, each string is assigned
137  *	to the next available sequence of 32-bit words of fractions
138  *	bits (starting with the most significant), right-aligned in
139  *	each sequence.
140  * #define MULTIPLE_THREADS if the system offers preemptively scheduled
141  *	multiple threads.  In this case, you must provide (or suitably
142  *	#define) two locks, acquired by ACQUIRE_DTOA_LOCK(n) and freed
143  *	by FREE_DTOA_LOCK(n) for n = 0 or 1.  (The second lock, accessed
144  *	in pow5mult, ensures lazy evaluation of only one copy of high
145  *	powers of 5; omitting this lock would introduce a small
146  *	probability of wasting memory, but would otherwise be harmless.)
147  *	You must also invoke freedtoa(s) to free the value s returned by
148  *	dtoa.  You may do so whether or not MULTIPLE_THREADS is #defined.
149  * #define IMPRECISE_INEXACT if you do not care about the setting of
150  *	the STRTOG_Inexact bits in the special case of doing IEEE double
151  *	precision conversions (which could also be done by the strtog in
152  *	dtoa.c).
153  * #define NO_HEX_FP to disable recognition of C9x's hexadecimal
154  *	floating-point constants.
155  * #define -DNO_ERRNO to suppress setting errno (in strtod.c and
156  *	strtodg.c).
157  * #define NO_STRING_H to use private versions of memcpy.
158  *	On some K&R systems, it may also be necessary to
159  *	#define DECLARE_SIZE_T in this case.
160  * #define YES_ALIAS to permit aliasing certain double values with
161  *	arrays of ULongs.  This leads to slightly better code with
162  *	some compilers and was always used prior to 19990916, but it
163  *	is not strictly legal and can cause trouble with aggressively
164  *	optimizing compilers (e.g., gcc 2.95.1 under -O2).
165  * #define USE_LOCALE to use the current locale's decimal_point value.
166  */
167 
168 #ifndef GDTOAIMP_H_INCLUDED
169 #define GDTOAIMP_H_INCLUDED
170 #include "gdtoa.h"
171 #include "gd_qnan.h"
172 
173 #ifdef DEBUG
174 #include "stdio.h"
175 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
176 #endif
177 
178 #include "stdlib.h"
179 #include "string.h"
180 
181 #ifdef KR_headers
182 #define Char char
183 #else
184 #define Char void
185 #endif
186 
187 #ifdef MALLOC
188 extern Char *MALLOC ANSI((size_t));
189 #else
190 #define MALLOC malloc
191 #endif
192 
193 #undef IEEE_Arith
194 #undef Avoid_Underflow
195 #ifdef IEEE_MC68k
196 #define IEEE_Arith
197 #endif
198 #ifdef IEEE_8087
199 #define IEEE_Arith
200 #endif
201 
202 #include "errno.h"
203 #ifdef Bad_float_h
204 
205 #ifdef IEEE_Arith
206 #define DBL_DIG 15
207 #define DBL_MAX_10_EXP 308
208 #define DBL_MAX_EXP 1024
209 #define FLT_RADIX 2
210 #define DBL_MAX 1.7976931348623157e+308
211 #endif
212 
213 #ifdef IBM
214 #define DBL_DIG 16
215 #define DBL_MAX_10_EXP 75
216 #define DBL_MAX_EXP 63
217 #define FLT_RADIX 16
218 #define DBL_MAX 7.2370055773322621e+75
219 #endif
220 
221 #ifdef VAX
222 #define DBL_DIG 16
223 #define DBL_MAX_10_EXP 38
224 #define DBL_MAX_EXP 127
225 #define FLT_RADIX 2
226 #define DBL_MAX 1.7014118346046923e+38
227 #define n_bigtens 2
228 #endif
229 
230 #ifndef LONG_MAX
231 #define LONG_MAX 2147483647
232 #endif
233 
234 #else /* ifndef Bad_float_h */
235 #include "float.h"
236 #endif /* Bad_float_h */
237 
238 #ifdef IEEE_Arith
239 #define Scale_Bit 0x10
240 #define n_bigtens 5
241 #endif
242 
243 #ifdef IBM
244 #define n_bigtens 3
245 #endif
246 
247 #ifdef VAX
248 #define n_bigtens 2
249 #endif
250 
251 #ifndef __MATH_H__
252 #include "math.h"
253 #endif
254 
255 #ifdef __cplusplus
256 extern "C" {
257 #endif
258 
259 #if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1
260 Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined.
261 #endif
262 
263 typedef union { double d; ULong L[2]; } U;
264 
265 #ifdef YES_ALIAS
266 #define dval(x) x
267 #ifdef IEEE_8087
268 #define word0(x) ((ULong *)&x)[1]
269 #define word1(x) ((ULong *)&x)[0]
270 #else
271 #define word0(x) ((ULong *)&x)[0]
272 #define word1(x) ((ULong *)&x)[1]
273 #endif
274 #else /* !YES_ALIAS */
275 #ifdef IEEE_8087
276 #define word0(x) ((U*)&x)->L[1]
277 #define word1(x) ((U*)&x)->L[0]
278 #else
279 #define word0(x) ((U*)&x)->L[0]
280 #define word1(x) ((U*)&x)->L[1]
281 #endif
282 #define dval(x) ((U*)&x)->d
283 #endif /* YES_ALIAS */
284 
285 /* The following definition of Storeinc is appropriate for MIPS processors.
286  * An alternative that might be better on some machines is
287  * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
288  */
289 #if defined(IEEE_8087) + defined(VAX)
290 #define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \
291 ((unsigned short *)a)[0] = (unsigned short)c, a++)
292 #else
293 #define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \
294 ((unsigned short *)a)[1] = (unsigned short)c, a++)
295 #endif
296 
297 /* #define P DBL_MANT_DIG */
298 /* Ten_pmax = floor(P*log(2)/log(5)) */
299 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
300 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
301 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
302 
303 #ifdef IEEE_Arith
304 #define Exp_shift  20
305 #define Exp_shift1 20
306 #define Exp_msk1    0x100000
307 #define Exp_msk11   0x100000
308 #define Exp_mask  0x7ff00000
309 #define P 53
310 #define Bias 1023
311 #define Emin (-1022)
312 #define Exp_1  0x3ff00000
313 #define Exp_11 0x3ff00000
314 #define Ebits 11
315 #define Frac_mask  0xfffff
316 #define Frac_mask1 0xfffff
317 #define Ten_pmax 22
318 #define Bletch 0x10
319 #define Bndry_mask  0xfffff
320 #define Bndry_mask1 0xfffff
321 #define LSB 1
322 #define Sign_bit 0x80000000
323 #define Log2P 1
324 #define Tiny0 0
325 #define Tiny1 1
326 #define Quick_max 14
327 #define Int_max 14
328 
329 #ifndef Flt_Rounds
330 #ifdef FLT_ROUNDS
331 #define Flt_Rounds FLT_ROUNDS
332 #else
333 #define Flt_Rounds 1
334 #endif
335 #endif /*Flt_Rounds*/
336 
337 #else /* ifndef IEEE_Arith */
338 #undef  Sudden_Underflow
339 #define Sudden_Underflow
340 #ifdef IBM
341 #undef Flt_Rounds
342 #define Flt_Rounds 0
343 #define Exp_shift  24
344 #define Exp_shift1 24
345 #define Exp_msk1   0x1000000
346 #define Exp_msk11  0x1000000
347 #define Exp_mask  0x7f000000
348 #define P 14
349 #define Bias 65
350 #define Exp_1  0x41000000
351 #define Exp_11 0x41000000
352 #define Ebits 8	/* exponent has 7 bits, but 8 is the right value in b2d */
353 #define Frac_mask  0xffffff
354 #define Frac_mask1 0xffffff
355 #define Bletch 4
356 #define Ten_pmax 22
357 #define Bndry_mask  0xefffff
358 #define Bndry_mask1 0xffffff
359 #define LSB 1
360 #define Sign_bit 0x80000000
361 #define Log2P 4
362 #define Tiny0 0x100000
363 #define Tiny1 0
364 #define Quick_max 14
365 #define Int_max 15
366 #else /* VAX */
367 #undef Flt_Rounds
368 #define Flt_Rounds 1
369 #define Exp_shift  23
370 #define Exp_shift1 7
371 #define Exp_msk1    0x80
372 #define Exp_msk11   0x800000
373 #define Exp_mask  0x7f80
374 #define P 56
375 #define Bias 129
376 #define Exp_1  0x40800000
377 #define Exp_11 0x4080
378 #define Ebits 8
379 #define Frac_mask  0x7fffff
380 #define Frac_mask1 0xffff007f
381 #define Ten_pmax 24
382 #define Bletch 2
383 #define Bndry_mask  0xffff007f
384 #define Bndry_mask1 0xffff007f
385 #define LSB 0x10000
386 #define Sign_bit 0x8000
387 #define Log2P 1
388 #define Tiny0 0x80
389 #define Tiny1 0
390 #define Quick_max 15
391 #define Int_max 15
392 #endif /* IBM, VAX */
393 #endif /* IEEE_Arith */
394 
395 #ifndef IEEE_Arith
396 #define ROUND_BIASED
397 #endif
398 
399 #ifdef RND_PRODQUOT
400 #define rounded_product(a,b) a = rnd_prod(a, b)
401 #define rounded_quotient(a,b) a = rnd_quot(a, b)
402 #ifdef KR_headers
403 extern double rnd_prod(), rnd_quot();
404 #else
405 extern double rnd_prod(double, double), rnd_quot(double, double);
406 #endif
407 #else
408 #define rounded_product(a,b) a *= b
409 #define rounded_quotient(a,b) a /= b
410 #endif
411 
412 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
413 #define Big1 0xffffffff
414 
415 #undef  Pack_16
416 #ifndef Pack_32
417 #define Pack_32
418 #endif
419 
420 #ifdef NO_LONG_LONG
421 #undef ULLong
422 #ifdef Just_16
423 #undef Pack_32
424 #define Pack_16
425 /* When Pack_32 is not defined, we store 16 bits per 32-bit Long.
426  * This makes some inner loops simpler and sometimes saves work
427  * during multiplications, but it often seems to make things slightly
428  * slower.  Hence the default is now to store 32 bits per Long.
429  */
430 #endif
431 #else	/* long long available */
432 #ifndef Llong
433 #define Llong long long
434 #endif
435 #ifndef ULLong
436 #define ULLong unsigned Llong
437 #endif
438 #endif /* NO_LONG_LONG */
439 
440 #ifdef Pack_32
441 #define ULbits 32
442 #define kshift 5
443 #define kmask 31
444 #define ALL_ON 0xffffffff
445 #else
446 #define ULbits 16
447 #define kshift 4
448 #define kmask 15
449 #define ALL_ON 0xffff
450 #endif
451 
452 #ifndef MULTIPLE_THREADS
453 #define ACQUIRE_DTOA_LOCK(n)	/*nothing*/
454 #define FREE_DTOA_LOCK(n)	/*nothing*/
455 #endif
456 
457 #define Kmax 15
458 
459  struct
460 Bigint {
461 	struct Bigint *next;
462 	int k, maxwds, sign, wds;
463 	ULong x[1];
464 	};
465 
466  typedef struct Bigint Bigint;
467 
468 #ifdef NO_STRING_H
469 #ifdef DECLARE_SIZE_T
470 typedef unsigned int size_t;
471 #endif
472 extern void memcpy_D2A ANSI((void*, const void*, size_t));
473 #define Bcopy(x,y) memcpy_D2A(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
474 #else /* !NO_STRING_H */
475 #define Bcopy(x,y) memcpy(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
476 #endif /* NO_STRING_H */
477 
478 #define Balloc Balloc_D2A
479 #define Bfree Bfree_D2A
480 #define ULtoQ ULtoQ_D2A
481 #define ULtof ULtof_D2A
482 #define ULtod ULtod_D2A
483 #define ULtodd ULtodd_D2A
484 #define ULtox ULtox_D2A
485 #define ULtoxL ULtoxL_D2A
486 #define any_on any_on_D2A
487 #define b2d b2d_D2A
488 #define bigtens bigtens_D2A
489 #define cmp cmp_D2A
490 #define copybits copybits_D2A
491 #define d2b d2b_D2A
492 #define decrement decrement_D2A
493 #define diff diff_D2A
494 #define dtoa_result dtoa_result_D2A
495 #define g__fmt g__fmt_D2A
496 #define gethex gethex_D2A
497 #define hexdig hexdig_D2A
498 #define hexnan hexnan_D2A
499 #define hi0bits(x) hi0bits_D2A((ULong)(x))
500 #define i2b i2b_D2A
501 #define increment increment_D2A
502 #define lo0bits lo0bits_D2A
503 #define lshift lshift_D2A
504 #define match match_D2A
505 #define mult mult_D2A
506 #define multadd multadd_D2A
507 #define nrv_alloc nrv_alloc_D2A
508 #define pow5mult pow5mult_D2A
509 #define quorem quorem_D2A
510 #define ratio ratio_D2A
511 #define rshift rshift_D2A
512 #define rv_alloc rv_alloc_D2A
513 #define s2b s2b_D2A
514 #define set_ones set_ones_D2A
515 #define strcp strcp_D2A
516 #define strtoIg strtoIg_D2A
517 #define sum sum_D2A
518 #define tens tens_D2A
519 #define tinytens tinytens_D2A
520 #define tinytens tinytens_D2A
521 #define trailz trailz_D2A
522 #define ulp ulp_D2A
523 
524  extern char *dtoa_result;
525  extern CONST double bigtens[], tens[], tinytens[];
526  extern unsigned char hexdig[];
527 
528  extern Bigint *Balloc ANSI((int));
529  extern void Bfree ANSI((Bigint*));
530  extern void ULtof ANSI((ULong*, ULong*, Long, int));
531  extern void ULtod ANSI((ULong*, ULong*, Long, int));
532  extern void ULtodd ANSI((ULong*, ULong*, Long, int));
533  extern void ULtoQ ANSI((ULong*, ULong*, Long, int));
534  extern void ULtox ANSI((UShort*, ULong*, Long, int));
535  extern void ULtoxL ANSI((ULong*, ULong*, Long, int));
536  extern ULong any_on ANSI((Bigint*, int));
537  extern double b2d ANSI((Bigint*, int*));
538  extern int cmp ANSI((Bigint*, Bigint*));
539  extern void copybits ANSI((ULong*, int, Bigint*));
540  extern Bigint *d2b ANSI((double, int*, int*));
541  extern int decrement ANSI((Bigint*));
542  extern Bigint *diff ANSI((Bigint*, Bigint*));
543  extern char *dtoa ANSI((double d, int mode, int ndigits,
544 			int *decpt, int *sign, char **rve));
545  extern char *g__fmt ANSI((char*, char*, char*, int, ULong));
546  extern int gethex ANSI((CONST char**, FPI*, Long*, Bigint**, int));
547  extern void hexdig_init_D2A(Void);
548  extern int hexnan ANSI((CONST char**, FPI*, ULong*));
549  extern int hi0bits_D2A ANSI((ULong));
550  extern Bigint *i2b ANSI((int));
551  extern Bigint *increment ANSI((Bigint*));
552  extern int lo0bits ANSI((ULong*));
553  extern Bigint *lshift ANSI((Bigint*, int));
554  extern int match ANSI((CONST char**, char*));
555  extern Bigint *mult ANSI((Bigint*, Bigint*));
556  extern Bigint *multadd ANSI((Bigint*, int, int));
557  extern char *nrv_alloc ANSI((char*, char **, int));
558  extern Bigint *pow5mult ANSI((Bigint*, int));
559  extern int quorem ANSI((Bigint*, Bigint*));
560  extern double ratio ANSI((Bigint*, Bigint*));
561  extern void rshift ANSI((Bigint*, int));
562  extern char *rv_alloc ANSI((int));
563  extern Bigint *s2b ANSI((CONST char*, int, int, ULong));
564  extern Bigint *set_ones ANSI((Bigint*, int));
565  extern char *strcp ANSI((char*, const char*));
566  extern int strtoIg ANSI((CONST char*, char**, FPI*, Long*, Bigint**, int*));
567  extern double strtod ANSI((const char *s00, char **se));
568  extern Bigint *sum ANSI((Bigint*, Bigint*));
569  extern int trailz ANSI((Bigint*));
570  extern double ulp ANSI((double));
571 
572 #ifdef __cplusplus
573 }
574 #endif
575 /*
576  * NAN_WORD0 and NAN_WORD1 are only referenced in strtod.c.  Prior to
577  * 20050115, they used to be hard-wired here (to 0x7ff80000 and 0,
578  * respectively), but now are determined by compiling and running
579  * qnan.c to generate gd_qnan.h, which specifies d_QNAN0 and d_QNAN1.
580  * Formerly gdtoaimp.h recommended supplying suitable -DNAN_WORD0=...
581  * and -DNAN_WORD1=...  values if necessary.  This should still work.
582  * (On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.)
583  */
584 #ifdef IEEE_Arith
585 #ifdef IEEE_MC68k
586 #define _0 0
587 #define _1 1
588 #ifndef NAN_WORD0
589 #define NAN_WORD0 d_QNAN0
590 #endif
591 #ifndef NAN_WORD1
592 #define NAN_WORD1 d_QNAN1
593 #endif
594 #else
595 #define _0 1
596 #define _1 0
597 #ifndef NAN_WORD0
598 #define NAN_WORD0 d_QNAN1
599 #endif
600 #ifndef NAN_WORD1
601 #define NAN_WORD1 d_QNAN0
602 #endif
603 #endif
604 #else
605 #undef INFNAN_CHECK
606 #endif
607 
608 #undef SI
609 #ifdef Sudden_Underflow
610 #define SI 1
611 #else
612 #define SI 0
613 #endif
614 
615 #endif /* GDTOAIMP_H_INCLUDED */
616