1 /* $NetBSD: gdtoaimp.h,v 1.14 2013/04/19 10:41:53 joerg Exp $ */
3 /****************************************************************
5 The author of this software is David M. Gay.
7 Copyright (C) 1998-2000 by Lucent Technologies
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
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
29 ****************************************************************/
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).
38 Please send bug reports to David M. Gay (dmg at acm dot org,
39 with " at " changed at "@" and " dot " changed to ".").
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
53 /* strtod for IEEE-, VAX-, and IBM-arithmetic machines.
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).
60 * Inspired loosely by William D. Clinger's paper "How to Read Floating
61 * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 112-126].
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
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 and arithmetic
100 * that rounds toward +Infinity.
101 * #define ROUND_BIASED_without_Round_Up for IEEE-format with biased
102 * rounding when the underlying floating-point arithmetic uses
103 * unbiased rounding. This prevent using ordinary floating-point
104 * arithmetic when the result could be computed with one rounding error.
105 * #define Inaccurate_Divide for IEEE-format with correctly rounded
106 * products but inaccurate quotients, e.g., for Intel i860.
107 * #define NO_LONG_LONG on machines that do not have a "long long"
108 * integer type (of >= 64 bits). On such machines, you can
109 * #define Just_16 to store 16 bits per 32-bit Long when doing
110 * high-precision integer arithmetic. Whether this speeds things
111 * up or slows things down depends on the machine and the number
112 * being converted. If long long is available and the name is
113 * something other than "long long", #define Llong to be the name,
114 * and if "unsigned Llong" does not work as an unsigned version of
115 * Llong, #define #ULLong to be the corresponding unsigned type.
116 * #define KR_headers for old-style C function headers.
117 * #define Bad_float_h if your system lacks a float.h or if it does not
118 * define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP,
119 * FLT_RADIX, FLT_ROUNDS, and DBL_MAX.
120 * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n)
121 * if memory is available and otherwise does something you deem
122 * appropriate. If MALLOC is undefined, malloc will be invoked
123 * directly -- and assumed always to succeed. Similarly, if you
124 * want something other than the system's free() to be called to
125 * recycle memory acquired from MALLOC, #define FREE to be the
126 * name of the alternate routine. (FREE or free is only called in
127 * pathological cases, e.g., in a gdtoa call after a gdtoa return in
128 * mode 3 with thousands of digits requested.)
129 * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
130 * memory allocations from a private pool of memory when possible.
131 * When used, the private pool is PRIVATE_MEM bytes long: 2304 bytes,
132 * unless #defined to be a different length. This default length
133 * suffices to get rid of MALLOC calls except for unusual cases,
134 * such as decimal-to-binary conversion of a very long string of
135 * digits. When converting IEEE double precision values, the
136 * longest string gdtoa can return is about 751 bytes long. For
137 * conversions by strtod of strings of 800 digits and all gdtoa
138 * conversions of IEEE doubles in single-threaded executions with
139 * 8-byte pointers, PRIVATE_MEM >= 7400 appears to suffice; with
140 * 4-byte pointers, PRIVATE_MEM >= 7112 appears adequate.
141 * #define NO_INFNAN_CHECK if you do not wish to have INFNAN_CHECK
142 * #defined automatically on IEEE systems. On such systems,
143 * when INFNAN_CHECK is #defined, strtod checks
144 * for Infinity and NaN (case insensitively).
145 * When INFNAN_CHECK is #defined and No_Hex_NaN is not #defined,
146 * strtodg also accepts (case insensitively) strings of the form
147 * NaN(x), where x is a string of hexadecimal digits (optionally
148 * preceded by 0x or 0X) and spaces; if there is only one string
149 * of hexadecimal digits, it is taken for the fraction bits of the
150 * resulting NaN; if there are two or more strings of hexadecimal
151 * digits, each string is assigned to the next available sequence
152 * of 32-bit words of fractions bits (starting with the most
153 * significant), right-aligned in each sequence.
154 * Unless GDTOA_NON_PEDANTIC_NANCHECK is #defined, input "NaN(...)"
155 * is consumed even when ... has the wrong form (in which case the
156 * "(...)" is consumed but ignored).
157 * #define MULTIPLE_THREADS if the system offers preemptively scheduled
158 * multiple threads. In this case, you must provide (or suitably
159 * #define) two locks, acquired by ACQUIRE_DTOA_LOCK(n) and freed
160 * by FREE_DTOA_LOCK(n) for n = 0 or 1. (The second lock, accessed
161 * in pow5mult, ensures lazy evaluation of only one copy of high
162 * powers of 5; omitting this lock would introduce a small
163 * probability of wasting memory, but would otherwise be harmless.)
164 * You must also invoke freedtoa(s) to free the value s returned by
165 * dtoa. You may do so whether or not MULTIPLE_THREADS is #defined.
166 * #define IMPRECISE_INEXACT if you do not care about the setting of
167 * the STRTOG_Inexact bits in the special case of doing IEEE double
168 * precision conversions (which could also be done by the strtod in
170 * #define NO_HEX_FP to disable recognition of C9x's hexadecimal
171 * floating-point constants.
172 * #define -DNO_ERRNO to suppress setting errno (in strtod.c and
174 * #define NO_STRING_H to use private versions of memcpy.
175 * On some K&R systems, it may also be necessary to
176 * #define DECLARE_SIZE_T in this case.
177 * #define USE_LOCALE to use the current locale's decimal_point value.
180 /* #define IEEE_{BIG,LITTLE}_ENDIAN in ${ARCHDIR}/gdtoa/arith.h */
184 #define Short int16_t
185 #define UShort uint16_t
187 #define ULong uint32_t
188 #define LLong int64_t
189 #define ULLong uint64_t
193 #define MULTIPLE_THREADS
197 #ifndef GDTOAIMP_H_INCLUDED
198 #define GDTOAIMP_H_INCLUDED
201 #ifdef Honor_FLT_ROUNDS
207 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
220 extern Char
*MALLOC
ANSI((size_t));
222 #define MALLOC malloc
226 #undef Avoid_Underflow
227 #ifdef IEEE_BIG_ENDIAN
230 #ifdef IEEE_LITTLE_ENDIAN
239 #define DBL_MAX_10_EXP 308
240 #define DBL_MAX_EXP 1024
242 #define DBL_MAX 1.7976931348623157e+308
247 #define DBL_MAX_10_EXP 75
248 #define DBL_MAX_EXP 63
250 #define DBL_MAX 7.2370055773322621e+75
255 #define DBL_MAX_10_EXP 38
256 #define DBL_MAX_EXP 127
258 #define DBL_MAX 1.7014118346046923e+38
263 #define LONG_MAX 2147483647
266 #else /* ifndef Bad_float_h */
268 #endif /* Bad_float_h */
271 #define Scale_Bit 0x10
289 #if defined(IEEE_LITTLE_ENDIAN) + defined(IEEE_BIG_ENDIAN) + defined(VAX) + defined(IBM) != 1
290 Exactly one of IEEE_LITTLE_ENDIAN
, IEEE_BIG_ENDIAN
, VAX
, or IBM should be defined
.
293 typedef union { double d
; ULong L
[2]; } __attribute__((__may_alias__
)) U
;
297 #ifdef IEEE_LITTLE_ENDIAN
298 #define word0(x) ((ULong *)x)[1]
299 #define word1(x) ((ULong *)x)[0]
301 #define word0(x) ((ULong *)x)[0]
302 #define word1(x) ((ULong *)x)[1]
304 #else /* !YES_ALIAS */
305 #ifdef IEEE_LITTLE_ENDIAN
306 #define word0(x) ( /* LINTED */ (U*)x)->L[1]
307 #define word1(x) ( /* LINTED */ (U*)x)->L[0]
309 #define word0(x) ( /* LINTED */ (U*)x)->L[0]
310 #define word1(x) ( /* LINTED */ (U*)x)->L[1]
312 #define dval(x) ( /* LINTED */ (U*)x)->d
313 #endif /* YES_ALIAS */
315 /* The following definition of Storeinc is appropriate for MIPS processors.
316 * An alternative that might be better on some machines is
317 * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
319 #if defined(IEEE_LITTLE_ENDIAN) + defined(VAX)
320 #define Storeinc(a,b,c) \
321 (((unsigned short *)(void *)a)[1] = (unsigned short)b, \
322 ((unsigned short *)(void *)a)[0] = (unsigned short)c, \
325 #define Storeinc(a,b,c) \
326 (((unsigned short *)(void *)a)[0] = (unsigned short)b, \
327 ((unsigned short *)(void *)a)[1] = (unsigned short)c, \
331 /* #define P DBL_MANT_DIG */
332 /* Ten_pmax = floor(P*log(2)/log(5)) */
333 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
334 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
335 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
339 #define Exp_shift1 20
340 #define Exp_msk1 0x100000
341 #define Exp_msk11 0x100000
342 #define Exp_mask 0x7ff00000
346 #define Exp_1 0x3ff00000
347 #define Exp_11 0x3ff00000
349 #define Frac_mask 0xfffff
350 #define Frac_mask1 0xfffff
353 #define Bndry_mask 0xfffff
354 #define Bndry_mask1 0xfffff
356 #define Sign_bit 0x80000000
365 #define Flt_Rounds FLT_ROUNDS
369 #endif /*Flt_Rounds*/
371 #else /* ifndef IEEE_Arith */
372 #undef Sudden_Underflow
373 #define Sudden_Underflow
378 #define Exp_shift1 24
379 #define Exp_msk1 0x1000000
380 #define Exp_msk11 0x1000000
381 #define Exp_mask 0x7f000000
384 #define Exp_1 0x41000000
385 #define Exp_11 0x41000000
386 #define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */
387 #define Frac_mask 0xffffff
388 #define Frac_mask1 0xffffff
391 #define Bndry_mask 0xefffff
392 #define Bndry_mask1 0xffffff
394 #define Sign_bit 0x80000000
396 #define Tiny0 0x100000
405 #define Exp_msk1 0x80
406 #define Exp_msk11 0x800000
407 #define Exp_mask 0x7f80
410 #define Emin (-127) /* XXX: Check this */
411 #define Exp_1 0x40800000
412 #define Exp_11 0x4080
414 #define Frac_mask 0x7fffff
415 #define Frac_mask1 0xffff007f
418 #define Bndry_mask 0xffff007f
419 #define Bndry_mask1 0xffff007f
421 #define Sign_bit 0x8000
427 #endif /* IBM, VAX */
428 #endif /* IEEE_Arith */
433 #ifdef ROUND_BIASED_without_Round_Up
440 #define rounded_product(a,b) a = rnd_prod(a, b)
441 #define rounded_quotient(a,b) a = rnd_quot(a, b)
443 extern double rnd_prod(), rnd_quot();
445 extern double rnd_prod(double, double), rnd_quot(double, double);
448 #define rounded_product(a,b) a *= b
449 #define rounded_quotient(a,b) a /= b
452 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
453 #define Big1 0xffffffff
465 /* When Pack_32 is not defined, we store 16 bits per 32-bit Long.
466 * This makes some inner loops simpler and sometimes saves work
467 * during multiplications, but it often seems to make things slightly
468 * slower. Hence the default is now to store 32 bits per Long.
471 #else /* long long available */
473 #define Llong long long
476 #define ULLong unsigned Llong
478 #endif /* NO_LONG_LONG */
484 #define ALL_ON 0xffffffff
489 #define ALL_ON 0xffff
492 #ifndef MULTIPLE_THREADS
493 #define ACQUIRE_DTOA_LOCK(n) /*nothing*/
494 #define FREE_DTOA_LOCK(n) /*nothing*/
496 #include "reentrant.h"
498 extern mutex_t __gdtoa_locks
[2];
500 #define ACQUIRE_DTOA_LOCK(n) \
503 mutex_lock(&__gdtoa_locks[n]); \
504 } while (/* CONSTCOND */ 0)
505 #define FREE_DTOA_LOCK(n) \
508 mutex_unlock(&__gdtoa_locks[n]); \
509 } while (/* CONSTCOND */ 0)
512 #define Kmax (sizeof(size_t) << 3)
517 int k
, maxwds
, sign
, wds
;
521 typedef struct Bigint Bigint
;
524 #ifdef DECLARE_SIZE_T
525 typedef unsigned int size_t;
527 extern void memcpy_D2A
ANSI((void*, const void*, size_t));
528 #define Bcopy(x,y) memcpy_D2A(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
529 #else /* !NO_STRING_H */
530 #define Bcopy(x,y) memcpy(&x->sign,&y->sign,y->wds*sizeof(ULong) + 2*sizeof(int))
531 #endif /* NO_STRING_H */
533 #define Balloc __Balloc_D2A
534 #define Bfree __Bfree_D2A
535 #define ULtoQ __ULtoQ_D2A
536 #define ULtof __ULtof_D2A
537 #define ULtod __ULtod_D2A
538 #define ULtodd __ULtodd_D2A
539 #define ULtox __ULtox_D2A
540 #define ULtoxL __ULtoxL_D2A
541 #define any_on __any_on_D2A
542 #define b2d __b2d_D2A
543 #define bigtens __bigtens_D2A
544 #define cmp __cmp_D2A
545 #define copybits __copybits_D2A
546 #define d2b __d2b_D2A
547 #define decrement __decrement_D2A
548 #define diff __diff_D2A
549 #define dtoa_result __dtoa_result_D2A
550 #define g__fmt __g__fmt_D2A
551 #define gethex __gethex_D2A
552 #define hexdig __hexdig_D2A
553 #define hexdig_init_D2A __hexdig_init_D2A
554 #define hexnan __hexnan_D2A
555 #define hi0bits __hi0bits_D2A
556 #define hi0bits_D2A __hi0bits_D2A
557 #define i2b __i2b_D2A
558 #define increment __increment_D2A
559 #define lo0bits __lo0bits_D2A
560 #define lshift __lshift_D2A
561 #define match __match_D2A
562 #define mult __mult_D2A
563 #define multadd __multadd_D2A
564 #define nrv_alloc __nrv_alloc_D2A
565 #define pow5mult __pow5mult_D2A
566 #define quorem __quorem_D2A
567 #define ratio __ratio_D2A
568 #define rshift __rshift_D2A
569 #define rv_alloc __rv_alloc_D2A
570 #define s2b __s2b_D2A
571 #define set_ones __set_ones_D2A
572 #define strcp __strcp_D2A
573 #define strcp_D2A __strcp_D2A
574 #define strtoIg __strtoIg_D2A
575 #define sum __sum_D2A
576 #define tens __tens_D2A
577 #define tinytens __tinytens_D2A
578 #define tinytens __tinytens_D2A
579 #define trailz __trailz_D2A
580 #define ulp __ulp_D2A
582 extern char *dtoa_result
;
583 extern CONST
double bigtens
[], tens
[], tinytens
[];
584 extern unsigned char hexdig
[];
586 extern Bigint
*Balloc
ANSI((int));
587 extern void Bfree
ANSI((Bigint
*));
588 extern void ULtof
ANSI((ULong
*, ULong
*, Long
, int));
589 extern void ULtod
ANSI((ULong
*, ULong
*, Long
, int));
590 extern void ULtodd
ANSI((ULong
*, ULong
*, Long
, int));
591 extern void ULtoQ
ANSI((ULong
*, ULong
*, Long
, int));
592 extern void ULtox
ANSI((UShort
*, ULong
*, Long
, int));
593 extern void ULtoxL
ANSI((ULong
*, ULong
*, Long
, int));
594 extern ULong any_on
ANSI((Bigint
*, int));
595 extern double b2d
ANSI((Bigint
*, int*));
596 extern int cmp
ANSI((Bigint
*, Bigint
*));
597 extern void copybits
ANSI((ULong
*, int, Bigint
*));
598 extern Bigint
*d2b
ANSI((double, int*, int*));
599 extern void decrement
ANSI((Bigint
*));
600 extern Bigint
*diff
ANSI((Bigint
*, Bigint
*));
601 extern char *dtoa
ANSI((double d
, int mode
, int ndigits
,
602 int *decpt
, int *sign
, char **rve
));
603 extern char *g__fmt
ANSI((char*, char*, char*, int, ULong
, size_t));
604 extern int gethex
ANSI((CONST
char**, CONST FPI
*, Long
*, Bigint
**, int, locale_t
));
605 extern void hexdig_init_D2A(Void
);
606 extern int hexnan
ANSI((CONST
char**, CONST FPI
*, ULong
*));
607 extern int hi0bits_D2A
ANSI((ULong
));
608 extern Bigint
*i2b
ANSI((int));
609 extern Bigint
*increment
ANSI((Bigint
*));
610 extern int lo0bits
ANSI((ULong
*));
611 extern Bigint
*lshift
ANSI((Bigint
*, int));
612 extern int match
ANSI((CONST
char**, CONST
char*));
613 extern Bigint
*mult
ANSI((Bigint
*, Bigint
*));
614 extern Bigint
*multadd
ANSI((Bigint
*, int, int));
615 extern char *nrv_alloc
ANSI((CONST
char*, char **, size_t));
616 extern Bigint
*pow5mult
ANSI((Bigint
*, int));
617 extern int quorem
ANSI((Bigint
*, Bigint
*));
618 extern double ratio
ANSI((Bigint
*, Bigint
*));
619 extern void rshift
ANSI((Bigint
*, int));
620 extern char *rv_alloc
ANSI((size_t));
621 extern Bigint
*s2b
ANSI((CONST
char*, int, int, ULong
, size_t));
622 extern Bigint
*set_ones
ANSI((Bigint
*, int));
623 extern char *strcp
ANSI((char*, const char*));
624 extern int strtoIg
ANSI((CONST
char*, char**, FPI
*, Long
*, Bigint
**, int*));
625 extern double strtod
ANSI((const char *s00
, char **se
));
626 extern Bigint
*sum
ANSI((Bigint
*, Bigint
*));
627 extern int trailz
ANSI((CONST Bigint
*));
628 extern double ulp
ANSI((U
*));
634 * NAN_WORD0 and NAN_WORD1 are only referenced in strtod.c. Prior to
635 * 20050115, they used to be hard-wired here (to 0x7ff80000 and 0,
636 * respectively), but now are determined by compiling and running
637 * qnan.c to generate gd_qnan.h, which specifies d_QNAN0 and d_QNAN1.
638 * Formerly gdtoaimp.h recommended supplying suitable -DNAN_WORD0=...
639 * and -DNAN_WORD1=... values if necessary. This should still work.
640 * (On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.)
643 #ifndef NO_INFNAN_CHECK
647 #ifdef IEEE_BIG_ENDIAN
651 #define NAN_WORD0 d_QNAN0
654 #define NAN_WORD1 d_QNAN1
660 #define NAN_WORD0 d_QNAN1
663 #define NAN_WORD1 d_QNAN0
671 #ifdef Sudden_Underflow
677 #endif /* GDTOAIMP_H_INCLUDED */