js/src/dtoa.c

Thu, 15 Jan 2015 15:55:04 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Thu, 15 Jan 2015 15:55:04 +0100
branch
TOR_BUG_9701
changeset 9
a63d609f5ebe
permissions
-rw-r--r--

Back out 97036ab72558 which inappropriately compared turds to third parties.

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

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