nsprpub/pr/src/misc/prdtoa.c

Wed, 31 Dec 2014 06:09:35 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Wed, 31 Dec 2014 06:09:35 +0100
changeset 0
6474c204b198
permissions
-rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
     2 /* This Source Code Form is subject to the terms of the Mozilla Public
     3  * License, v. 2.0. If a copy of the MPL was not distributed with this
     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
     6 /*
     7  * This file is based on the third-party code dtoa.c.  We minimize our
     8  * modifications to third-party code to make it easy to merge new versions.
     9  * The author of dtoa.c was not willing to add the parentheses suggested by
    10  * GCC, so we suppress these warnings.
    11  */
    12 #if (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 2)
    13 #pragma GCC diagnostic ignored "-Wparentheses"
    14 #endif
    16 #include "primpl.h"
    17 #include "prbit.h"
    19 #define MULTIPLE_THREADS
    20 #define ACQUIRE_DTOA_LOCK(n)	PR_Lock(dtoa_lock[n])
    21 #define FREE_DTOA_LOCK(n)	PR_Unlock(dtoa_lock[n])
    23 static PRLock *dtoa_lock[2];
    25 void _PR_InitDtoa(void)
    26 {
    27     dtoa_lock[0] = PR_NewLock();
    28     dtoa_lock[1] = PR_NewLock();
    29 }
    31 void _PR_CleanupDtoa(void)
    32 {
    33     PR_DestroyLock(dtoa_lock[0]);
    34     dtoa_lock[0] = NULL;
    35     PR_DestroyLock(dtoa_lock[1]);
    36     dtoa_lock[1] = NULL;
    38     /* FIXME: deal with freelist and p5s. */
    39 }
    41 #if !defined(__ARM_EABI__) \
    42     && (defined(__arm) || defined(__arm__) || defined(__arm26__) \
    43     || defined(__arm32__))
    44 #define IEEE_ARM
    45 #elif defined(IS_LITTLE_ENDIAN)
    46 #define IEEE_8087
    47 #else
    48 #define IEEE_MC68k
    49 #endif
    51 #define Long PRInt32
    52 #define ULong PRUint32
    53 #define NO_LONG_LONG
    55 #define No_Hex_NaN
    57 /****************************************************************
    58  *
    59  * The author of this software is David M. Gay.
    60  *
    61  * Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
    62  *
    63  * Permission to use, copy, modify, and distribute this software for any
    64  * purpose without fee is hereby granted, provided that this entire notice
    65  * is included in all copies of any software which is or includes a copy
    66  * or modification of this software and in all copies of the supporting
    67  * documentation for such software.
    68  *
    69  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
    70  * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY
    71  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
    72  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
    73  *
    74  ***************************************************************/
    76 /* Please send bug reports to David M. Gay (dmg at acm dot org,
    77  * with " at " changed at "@" and " dot " changed to ".").	*/
    79 /* On a machine with IEEE extended-precision registers, it is
    80  * necessary to specify double-precision (53-bit) rounding precision
    81  * before invoking strtod or dtoa.  If the machine uses (the equivalent
    82  * of) Intel 80x87 arithmetic, the call
    83  *	_control87(PC_53, MCW_PC);
    84  * does this with many compilers.  Whether this or another call is
    85  * appropriate depends on the compiler; for this to work, it may be
    86  * necessary to #include "float.h" or another system-dependent header
    87  * file.
    88  */
    90 /* strtod for IEEE-, VAX-, and IBM-arithmetic machines.
    91  *
    92  * This strtod returns a nearest machine number to the input decimal
    93  * string (or sets errno to ERANGE).  With IEEE arithmetic, ties are
    94  * broken by the IEEE round-even rule.  Otherwise ties are broken by
    95  * biased rounding (add half and chop).
    96  *
    97  * Inspired loosely by William D. Clinger's paper "How to Read Floating
    98  * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 92-101].
    99  *
   100  * Modifications:
   101  *
   102  *	1. We only require IEEE, IBM, or VAX double-precision
   103  *		arithmetic (not IEEE double-extended).
   104  *	2. We get by with floating-point arithmetic in a case that
   105  *		Clinger missed -- when we're computing d * 10^n
   106  *		for a small integer d and the integer n is not too
   107  *		much larger than 22 (the maximum integer k for which
   108  *		we can represent 10^k exactly), we may be able to
   109  *		compute (d*10^k) * 10^(e-k) with just one roundoff.
   110  *	3. Rather than a bit-at-a-time adjustment of the binary
   111  *		result in the hard case, we use floating-point
   112  *		arithmetic to determine the adjustment to within
   113  *		one bit; only in really hard cases do we need to
   114  *		compute a second residual.
   115  *	4. Because of 3., we don't need a large table of powers of 10
   116  *		for ten-to-e (just some small tables, e.g. of 10^k
   117  *		for 0 <= k <= 22).
   118  */
   120 /*
   121  * #define IEEE_8087 for IEEE-arithmetic machines where the least
   122  *	significant byte has the lowest address.
   123  * #define IEEE_MC68k for IEEE-arithmetic machines where the most
   124  *	significant byte has the lowest address.
   125  * #define IEEE_ARM for IEEE-arithmetic machines where the two words
   126  *	in a double are stored in big endian order but the two shorts
   127  *	in a word are still stored in little endian order.
   128  * #define Long int on machines with 32-bit ints and 64-bit longs.
   129  * #define IBM for IBM mainframe-style floating-point arithmetic.
   130  * #define VAX for VAX-style floating-point arithmetic (D_floating).
   131  * #define No_leftright to omit left-right logic in fast floating-point
   132  *	computation of dtoa.
   133  * #define Honor_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3
   134  *	and strtod and dtoa should round accordingly.
   135  * #define Check_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3
   136  *	and Honor_FLT_ROUNDS is not #defined.
   137  * #define RND_PRODQUOT to use rnd_prod and rnd_quot (assembly routines
   138  *	that use extended-precision instructions to compute rounded
   139  *	products and quotients) with IBM.
   140  * #define ROUND_BIASED for IEEE-format with biased rounding.
   141  * #define Inaccurate_Divide for IEEE-format with correctly rounded
   142  *	products but inaccurate quotients, e.g., for Intel i860.
   143  * #define NO_LONG_LONG on machines that do not have a "long long"
   144  *	integer type (of >= 64 bits).  On such machines, you can
   145  *	#define Just_16 to store 16 bits per 32-bit Long when doing
   146  *	high-precision integer arithmetic.  Whether this speeds things
   147  *	up or slows things down depends on the machine and the number
   148  *	being converted.  If long long is available and the name is
   149  *	something other than "long long", #define Llong to be the name,
   150  *	and if "unsigned Llong" does not work as an unsigned version of
   151  *	Llong, #define #ULLong to be the corresponding unsigned type.
   152  * #define KR_headers for old-style C function headers.
   153  * #define Bad_float_h if your system lacks a float.h or if it does not
   154  *	define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP,
   155  *	FLT_RADIX, FLT_ROUNDS, and DBL_MAX.
   156  * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n)
   157  *	if memory is available and otherwise does something you deem
   158  *	appropriate.  If MALLOC is undefined, malloc will be invoked
   159  *	directly -- and assumed always to succeed.  Similarly, if you
   160  *	want something other than the system's free() to be called to
   161  *	recycle memory acquired from MALLOC, #define FREE to be the
   162  *	name of the alternate routine.  (FREE or free is only called in
   163  *	pathological cases, e.g., in a dtoa call after a dtoa return in
   164  *	mode 3 with thousands of digits requested.)
   165  * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
   166  *	memory allocations from a private pool of memory when possible.
   167  *	When used, the private pool is PRIVATE_MEM bytes long:  2304 bytes,
   168  *	unless #defined to be a different length.  This default length
   169  *	suffices to get rid of MALLOC calls except for unusual cases,
   170  *	such as decimal-to-binary conversion of a very long string of
   171  *	digits.  The longest string dtoa can return is about 751 bytes
   172  *	long.  For conversions by strtod of strings of 800 digits and
   173  *	all dtoa conversions in single-threaded executions with 8-byte
   174  *	pointers, PRIVATE_MEM >= 7400 appears to suffice; with 4-byte
   175  *	pointers, PRIVATE_MEM >= 7112 appears adequate.
   176  * #define INFNAN_CHECK on IEEE systems to cause strtod to check for
   177  *	Infinity and NaN (case insensitively).  On some systems (e.g.,
   178  *	some HP systems), it may be necessary to #define NAN_WORD0
   179  *	appropriately -- to the most significant word of a quiet NaN.
   180  *	(On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.)
   181  *	When INFNAN_CHECK is #defined and No_Hex_NaN is not #defined,
   182  *	strtod also accepts (case insensitively) strings of the form
   183  *	NaN(x), where x is a string of hexadecimal digits and spaces;
   184  *	if there is only one string of hexadecimal digits, it is taken
   185  *	for the 52 fraction bits of the resulting NaN; if there are two
   186  *	or more strings of hex digits, the first is for the high 20 bits,
   187  *	the second and subsequent for the low 32 bits, with intervening
   188  *	white space ignored; but if this results in none of the 52
   189  *	fraction bits being on (an IEEE Infinity symbol), then NAN_WORD0
   190  *	and NAN_WORD1 are used instead.
   191  * #define MULTIPLE_THREADS if the system offers preemptively scheduled
   192  *	multiple threads.  In this case, you must provide (or suitably
   193  *	#define) two locks, acquired by ACQUIRE_DTOA_LOCK(n) and freed
   194  *	by FREE_DTOA_LOCK(n) for n = 0 or 1.  (The second lock, accessed
   195  *	in pow5mult, ensures lazy evaluation of only one copy of high
   196  *	powers of 5; omitting this lock would introduce a small
   197  *	probability of wasting memory, but would otherwise be harmless.)
   198  *	You must also invoke freedtoa(s) to free the value s returned by
   199  *	dtoa.  You may do so whether or not MULTIPLE_THREADS is #defined.
   200  * #define NO_IEEE_Scale to disable new (Feb. 1997) logic in strtod that
   201  *	avoids underflows on inputs whose result does not underflow.
   202  *	If you #define NO_IEEE_Scale on a machine that uses IEEE-format
   203  *	floating-point numbers and flushes underflows to zero rather
   204  *	than implementing gradual underflow, then you must also #define
   205  *	Sudden_Underflow.
   206  * #define USE_LOCALE to use the current locale's decimal_point value.
   207  * #define SET_INEXACT if IEEE arithmetic is being used and extra
   208  *	computation should be done to set the inexact flag when the
   209  *	result is inexact and avoid setting inexact when the result
   210  *	is exact.  In this case, dtoa.c must be compiled in
   211  *	an environment, perhaps provided by #include "dtoa.c" in a
   212  *	suitable wrapper, that defines two functions,
   213  *		int get_inexact(void);
   214  *		void clear_inexact(void);
   215  *	such that get_inexact() returns a nonzero value if the
   216  *	inexact bit is already set, and clear_inexact() sets the
   217  *	inexact bit to 0.  When SET_INEXACT is #defined, strtod
   218  *	also does extra computations to set the underflow and overflow
   219  *	flags when appropriate (i.e., when the result is tiny and
   220  *	inexact or when it is a numeric value rounded to +-infinity).
   221  * #define NO_ERRNO if strtod should not assign errno = ERANGE when
   222  *	the result overflows to +-Infinity or underflows to 0.
   223  */
   225 #ifndef Long
   226 #define Long long
   227 #endif
   228 #ifndef ULong
   229 typedef unsigned Long ULong;
   230 #endif
   232 #ifdef DEBUG
   233 #include "stdio.h"
   234 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
   235 #endif
   237 #include "stdlib.h"
   238 #include "string.h"
   240 #ifdef USE_LOCALE
   241 #include "locale.h"
   242 #endif
   244 #ifdef MALLOC
   245 #ifdef KR_headers
   246 extern char *MALLOC();
   247 #else
   248 extern void *MALLOC(size_t);
   249 #endif
   250 #else
   251 #define MALLOC malloc
   252 #endif
   254 #ifndef Omit_Private_Memory
   255 #ifndef PRIVATE_MEM
   256 #define PRIVATE_MEM 2304
   257 #endif
   258 #define PRIVATE_mem ((PRIVATE_MEM+sizeof(double)-1)/sizeof(double))
   259 static double private_mem[PRIVATE_mem], *pmem_next = private_mem;
   260 #endif
   262 #undef IEEE_Arith
   263 #undef Avoid_Underflow
   264 #ifdef IEEE_MC68k
   265 #define IEEE_Arith
   266 #endif
   267 #ifdef IEEE_8087
   268 #define IEEE_Arith
   269 #endif
   270 #ifdef IEEE_ARM
   271 #define IEEE_Arith
   272 #endif
   274 #include "errno.h"
   276 #ifdef Bad_float_h
   278 #ifdef IEEE_Arith
   279 #define DBL_DIG 15
   280 #define DBL_MAX_10_EXP 308
   281 #define DBL_MAX_EXP 1024
   282 #define FLT_RADIX 2
   283 #endif /*IEEE_Arith*/
   285 #ifdef IBM
   286 #define DBL_DIG 16
   287 #define DBL_MAX_10_EXP 75
   288 #define DBL_MAX_EXP 63
   289 #define FLT_RADIX 16
   290 #define DBL_MAX 7.2370055773322621e+75
   291 #endif
   293 #ifdef VAX
   294 #define DBL_DIG 16
   295 #define DBL_MAX_10_EXP 38
   296 #define DBL_MAX_EXP 127
   297 #define FLT_RADIX 2
   298 #define DBL_MAX 1.7014118346046923e+38
   299 #endif
   301 #ifndef LONG_MAX
   302 #define LONG_MAX 2147483647
   303 #endif
   305 #else /* ifndef Bad_float_h */
   306 #include "float.h"
   307 /*
   308  * MacOS 10.2 defines the macro FLT_ROUNDS to an internal function
   309  * which does not exist on 10.1.  We can safely #define it to 1 here
   310  * to allow 10.2 builds to run on 10.1, since we can't use fesetround()
   311  * (which does not exist on 10.1 either).
   312  */
   313 #if defined(XP_MACOSX) && (!defined(MAC_OS_X_VERSION_10_2) || \
   314     MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_2)
   315 #undef FLT_ROUNDS
   316 #define FLT_ROUNDS 1
   317 #endif /* DT < 10.2 */
   318 #endif /* Bad_float_h */
   320 #ifndef __MATH_H__
   321 #include "math.h"
   322 #endif
   324 #ifdef __cplusplus
   325 extern "C" {
   326 #endif
   328 #ifndef CONST
   329 #ifdef KR_headers
   330 #define CONST /* blank */
   331 #else
   332 #define CONST const
   333 #endif
   334 #endif
   336 #if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(IEEE_ARM) + defined(VAX) + defined(IBM) != 1
   337 Exactly one of IEEE_8087, IEEE_MC68k, IEEE_ARM, VAX, or IBM should be defined.
   338 #endif
   340 typedef union { double d; ULong L[2]; } U;
   342 #define dval(x) (x).d
   343 #ifdef IEEE_8087
   344 #define word0(x) (x).L[1]
   345 #define word1(x) (x).L[0]
   346 #else
   347 #define word0(x) (x).L[0]
   348 #define word1(x) (x).L[1]
   349 #endif
   351 /* The following definition of Storeinc is appropriate for MIPS processors.
   352  * An alternative that might be better on some machines is
   353  * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
   354  */
   355 #if defined(IEEE_8087) + defined(IEEE_ARM) + defined(VAX)
   356 #define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \
   357 ((unsigned short *)a)[0] = (unsigned short)c, a++)
   358 #else
   359 #define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \
   360 ((unsigned short *)a)[1] = (unsigned short)c, a++)
   361 #endif
   363 /* #define P DBL_MANT_DIG */
   364 /* Ten_pmax = floor(P*log(2)/log(5)) */
   365 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
   366 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
   367 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
   369 #ifdef IEEE_Arith
   370 #define Exp_shift  20
   371 #define Exp_shift1 20
   372 #define Exp_msk1    0x100000
   373 #define Exp_msk11   0x100000
   374 #define Exp_mask  0x7ff00000
   375 #define P 53
   376 #define Bias 1023
   377 #define Emin (-1022)
   378 #define Exp_1  0x3ff00000
   379 #define Exp_11 0x3ff00000
   380 #define Ebits 11
   381 #define Frac_mask  0xfffff
   382 #define Frac_mask1 0xfffff
   383 #define Ten_pmax 22
   384 #define Bletch 0x10
   385 #define Bndry_mask  0xfffff
   386 #define Bndry_mask1 0xfffff
   387 #define LSB 1
   388 #define Sign_bit 0x80000000
   389 #define Log2P 1
   390 #define Tiny0 0
   391 #define Tiny1 1
   392 #define Quick_max 14
   393 #define Int_max 14
   394 #ifndef NO_IEEE_Scale
   395 #define Avoid_Underflow
   396 #ifdef Flush_Denorm	/* debugging option */
   397 #undef Sudden_Underflow
   398 #endif
   399 #endif
   401 #ifndef Flt_Rounds
   402 #ifdef FLT_ROUNDS
   403 #define Flt_Rounds FLT_ROUNDS
   404 #else
   405 #define Flt_Rounds 1
   406 #endif
   407 #endif /*Flt_Rounds*/
   409 #ifdef Honor_FLT_ROUNDS
   410 #define Rounding rounding
   411 #undef Check_FLT_ROUNDS
   412 #define Check_FLT_ROUNDS
   413 #else
   414 #define Rounding Flt_Rounds
   415 #endif
   417 #else /* ifndef IEEE_Arith */
   418 #undef Check_FLT_ROUNDS
   419 #undef Honor_FLT_ROUNDS
   420 #undef SET_INEXACT
   421 #undef  Sudden_Underflow
   422 #define Sudden_Underflow
   423 #ifdef IBM
   424 #undef Flt_Rounds
   425 #define Flt_Rounds 0
   426 #define Exp_shift  24
   427 #define Exp_shift1 24
   428 #define Exp_msk1   0x1000000
   429 #define Exp_msk11  0x1000000
   430 #define Exp_mask  0x7f000000
   431 #define P 14
   432 #define Bias 65
   433 #define Exp_1  0x41000000
   434 #define Exp_11 0x41000000
   435 #define Ebits 8	/* exponent has 7 bits, but 8 is the right value in b2d */
   436 #define Frac_mask  0xffffff
   437 #define Frac_mask1 0xffffff
   438 #define Bletch 4
   439 #define Ten_pmax 22
   440 #define Bndry_mask  0xefffff
   441 #define Bndry_mask1 0xffffff
   442 #define LSB 1
   443 #define Sign_bit 0x80000000
   444 #define Log2P 4
   445 #define Tiny0 0x100000
   446 #define Tiny1 0
   447 #define Quick_max 14
   448 #define Int_max 15
   449 #else /* VAX */
   450 #undef Flt_Rounds
   451 #define Flt_Rounds 1
   452 #define Exp_shift  23
   453 #define Exp_shift1 7
   454 #define Exp_msk1    0x80
   455 #define Exp_msk11   0x800000
   456 #define Exp_mask  0x7f80
   457 #define P 56
   458 #define Bias 129
   459 #define Exp_1  0x40800000
   460 #define Exp_11 0x4080
   461 #define Ebits 8
   462 #define Frac_mask  0x7fffff
   463 #define Frac_mask1 0xffff007f
   464 #define Ten_pmax 24
   465 #define Bletch 2
   466 #define Bndry_mask  0xffff007f
   467 #define Bndry_mask1 0xffff007f
   468 #define LSB 0x10000
   469 #define Sign_bit 0x8000
   470 #define Log2P 1
   471 #define Tiny0 0x80
   472 #define Tiny1 0
   473 #define Quick_max 15
   474 #define Int_max 15
   475 #endif /* IBM, VAX */
   476 #endif /* IEEE_Arith */
   478 #ifndef IEEE_Arith
   479 #define ROUND_BIASED
   480 #endif
   482 #ifdef RND_PRODQUOT
   483 #define rounded_product(a,b) a = rnd_prod(a, b)
   484 #define rounded_quotient(a,b) a = rnd_quot(a, b)
   485 #ifdef KR_headers
   486 extern double rnd_prod(), rnd_quot();
   487 #else
   488 extern double rnd_prod(double, double), rnd_quot(double, double);
   489 #endif
   490 #else
   491 #define rounded_product(a,b) a *= b
   492 #define rounded_quotient(a,b) a /= b
   493 #endif
   495 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
   496 #define Big1 0xffffffff
   498 #ifndef Pack_32
   499 #define Pack_32
   500 #endif
   502 #ifdef KR_headers
   503 #define FFFFFFFF ((((unsigned long)0xffff)<<16)|(unsigned long)0xffff)
   504 #else
   505 #define FFFFFFFF 0xffffffffUL
   506 #endif
   508 #ifdef NO_LONG_LONG
   509 #undef ULLong
   510 #ifdef Just_16
   511 #undef Pack_32
   512 /* When Pack_32 is not defined, we store 16 bits per 32-bit Long.
   513  * This makes some inner loops simpler and sometimes saves work
   514  * during multiplications, but it often seems to make things slightly
   515  * slower.  Hence the default is now to store 32 bits per Long.
   516  */
   517 #endif
   518 #else	/* long long available */
   519 #ifndef Llong
   520 #define Llong long long
   521 #endif
   522 #ifndef ULLong
   523 #define ULLong unsigned Llong
   524 #endif
   525 #endif /* NO_LONG_LONG */
   527 #ifndef MULTIPLE_THREADS
   528 #define ACQUIRE_DTOA_LOCK(n)	/*nothing*/
   529 #define FREE_DTOA_LOCK(n)	/*nothing*/
   530 #endif
   532 #define Kmax 7
   534  struct
   535 Bigint {
   536 	struct Bigint *next;
   537 	int k, maxwds, sign, wds;
   538 	ULong x[1];
   539 	};
   541  typedef struct Bigint Bigint;
   543  static Bigint *freelist[Kmax+1];
   545  static Bigint *
   546 Balloc
   547 #ifdef KR_headers
   548 	(k) int k;
   549 #else
   550 	(int k)
   551 #endif
   552 {
   553 	int x;
   554 	Bigint *rv;
   555 #ifndef Omit_Private_Memory
   556 	unsigned int len;
   557 #endif
   559 	ACQUIRE_DTOA_LOCK(0);
   560 	/* The k > Kmax case does not need ACQUIRE_DTOA_LOCK(0), */
   561 	/* but this case seems very unlikely. */
   562 	if (k <= Kmax && (rv = freelist[k]))
   563 		freelist[k] = rv->next;
   564 	else {
   565 		x = 1 << k;
   566 #ifdef Omit_Private_Memory
   567 		rv = (Bigint *)MALLOC(sizeof(Bigint) + (x-1)*sizeof(ULong));
   568 #else
   569 		len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1)
   570 			/sizeof(double);
   571 		if (k <= Kmax && pmem_next - private_mem + len <= PRIVATE_mem) {
   572 			rv = (Bigint*)pmem_next;
   573 			pmem_next += len;
   574 			}
   575 		else
   576 			rv = (Bigint*)MALLOC(len*sizeof(double));
   577 #endif
   578 		rv->k = k;
   579 		rv->maxwds = x;
   580 		}
   581 	FREE_DTOA_LOCK(0);
   582 	rv->sign = rv->wds = 0;
   583 	return rv;
   584 	}
   586  static void
   587 Bfree
   588 #ifdef KR_headers
   589 	(v) Bigint *v;
   590 #else
   591 	(Bigint *v)
   592 #endif
   593 {
   594 	if (v) {
   595 		if (v->k > Kmax)
   596 #ifdef FREE
   597 			FREE((void*)v);
   598 #else
   599 			free((void*)v);
   600 #endif
   601 		else {
   602 			ACQUIRE_DTOA_LOCK(0);
   603 			v->next = freelist[v->k];
   604 			freelist[v->k] = v;
   605 			FREE_DTOA_LOCK(0);
   606 			}
   607 		}
   608 	}
   610 #define Bcopy(x,y) memcpy((char *)&x->sign, (char *)&y->sign, \
   611 y->wds*sizeof(Long) + 2*sizeof(int))
   613  static Bigint *
   614 multadd
   615 #ifdef KR_headers
   616 	(b, m, a) Bigint *b; int m, a;
   617 #else
   618 	(Bigint *b, int m, int a)	/* multiply by m and add a */
   619 #endif
   620 {
   621 	int i, wds;
   622 #ifdef ULLong
   623 	ULong *x;
   624 	ULLong carry, y;
   625 #else
   626 	ULong carry, *x, y;
   627 #ifdef Pack_32
   628 	ULong xi, z;
   629 #endif
   630 #endif
   631 	Bigint *b1;
   633 	wds = b->wds;
   634 	x = b->x;
   635 	i = 0;
   636 	carry = a;
   637 	do {
   638 #ifdef ULLong
   639 		y = *x * (ULLong)m + carry;
   640 		carry = y >> 32;
   641 		*x++ = y & FFFFFFFF;
   642 #else
   643 #ifdef Pack_32
   644 		xi = *x;
   645 		y = (xi & 0xffff) * m + carry;
   646 		z = (xi >> 16) * m + (y >> 16);
   647 		carry = z >> 16;
   648 		*x++ = (z << 16) + (y & 0xffff);
   649 #else
   650 		y = *x * m + carry;
   651 		carry = y >> 16;
   652 		*x++ = y & 0xffff;
   653 #endif
   654 #endif
   655 		}
   656 		while(++i < wds);
   657 	if (carry) {
   658 		if (wds >= b->maxwds) {
   659 			b1 = Balloc(b->k+1);
   660 			Bcopy(b1, b);
   661 			Bfree(b);
   662 			b = b1;
   663 			}
   664 		b->x[wds++] = carry;
   665 		b->wds = wds;
   666 		}
   667 	return b;
   668 	}
   670  static Bigint *
   671 s2b
   672 #ifdef KR_headers
   673 	(s, nd0, nd, y9) CONST char *s; int nd0, nd; ULong y9;
   674 #else
   675 	(CONST char *s, int nd0, int nd, ULong y9)
   676 #endif
   677 {
   678 	Bigint *b;
   679 	int i, k;
   680 	Long x, y;
   682 	x = (nd + 8) / 9;
   683 	for(k = 0, y = 1; x > y; y <<= 1, k++) ;
   684 #ifdef Pack_32
   685 	b = Balloc(k);
   686 	b->x[0] = y9;
   687 	b->wds = 1;
   688 #else
   689 	b = Balloc(k+1);
   690 	b->x[0] = y9 & 0xffff;
   691 	b->wds = (b->x[1] = y9 >> 16) ? 2 : 1;
   692 #endif
   694 	i = 9;
   695 	if (9 < nd0) {
   696 		s += 9;
   697 		do b = multadd(b, 10, *s++ - '0');
   698 			while(++i < nd0);
   699 		s++;
   700 		}
   701 	else
   702 		s += 10;
   703 	for(; i < nd; i++)
   704 		b = multadd(b, 10, *s++ - '0');
   705 	return b;
   706 	}
   708  static int
   709 hi0bits
   710 #ifdef KR_headers
   711 	(x) register ULong x;
   712 #else
   713 	(register ULong x)
   714 #endif
   715 {
   716 #ifdef PR_HAVE_BUILTIN_BITSCAN32
   717 	return( (!x) ? 32 : pr_bitscan_clz32(x) );
   718 #else
   719 	register int k = 0;
   721 	if (!(x & 0xffff0000)) {
   722 		k = 16;
   723 		x <<= 16;
   724 		}
   725 	if (!(x & 0xff000000)) {
   726 		k += 8;
   727 		x <<= 8;
   728 		}
   729 	if (!(x & 0xf0000000)) {
   730 		k += 4;
   731 		x <<= 4;
   732 		}
   733 	if (!(x & 0xc0000000)) {
   734 		k += 2;
   735 		x <<= 2;
   736 		}
   737 	if (!(x & 0x80000000)) {
   738 		k++;
   739 		if (!(x & 0x40000000))
   740 			return 32;
   741 		}
   742 	return k;
   743 #endif /* PR_HAVE_BUILTIN_BITSCAN32 */
   744 	}
   746  static int
   747 lo0bits
   748 #ifdef KR_headers
   749 	(y) ULong *y;
   750 #else
   751 	(ULong *y)
   752 #endif
   753 {
   754 #ifdef PR_HAVE_BUILTIN_BITSCAN32
   755 	int k;
   756 	ULong x = *y;
   758 	if (x>1)
   759 		*y = ( x >> (k = pr_bitscan_ctz32(x)) );
   760 	else
   761 		k = ((x ^ 1) << 5);
   762 #else
   763 	register int k;
   764 	register ULong x = *y;
   766 	if (x & 7) {
   767 		if (x & 1)
   768 			return 0;
   769 		if (x & 2) {
   770 			*y = x >> 1;
   771 			return 1;
   772 			}
   773 		*y = x >> 2;
   774 		return 2;
   775 		}
   776 	k = 0;
   777 	if (!(x & 0xffff)) {
   778 		k = 16;
   779 		x >>= 16;
   780 		}
   781 	if (!(x & 0xff)) {
   782 		k += 8;
   783 		x >>= 8;
   784 		}
   785 	if (!(x & 0xf)) {
   786 		k += 4;
   787 		x >>= 4;
   788 		}
   789 	if (!(x & 0x3)) {
   790 		k += 2;
   791 		x >>= 2;
   792 		}
   793 	if (!(x & 1)) {
   794 		k++;
   795 		x >>= 1;
   796 		if (!x)
   797 			return 32;
   798 		}
   799 	*y = x;
   800 #endif /* PR_HAVE_BUILTIN_BITSCAN32 */
   801 	return k;
   802 	}
   804  static Bigint *
   805 i2b
   806 #ifdef KR_headers
   807 	(i) int i;
   808 #else
   809 	(int i)
   810 #endif
   811 {
   812 	Bigint *b;
   814 	b = Balloc(1);
   815 	b->x[0] = i;
   816 	b->wds = 1;
   817 	return b;
   818 	}
   820  static Bigint *
   821 mult
   822 #ifdef KR_headers
   823 	(a, b) Bigint *a, *b;
   824 #else
   825 	(Bigint *a, Bigint *b)
   826 #endif
   827 {
   828 	Bigint *c;
   829 	int k, wa, wb, wc;
   830 	ULong *x, *xa, *xae, *xb, *xbe, *xc, *xc0;
   831 	ULong y;
   832 #ifdef ULLong
   833 	ULLong carry, z;
   834 #else
   835 	ULong carry, z;
   836 #ifdef Pack_32
   837 	ULong z2;
   838 #endif
   839 #endif
   841 	if (a->wds < b->wds) {
   842 		c = a;
   843 		a = b;
   844 		b = c;
   845 		}
   846 	k = a->k;
   847 	wa = a->wds;
   848 	wb = b->wds;
   849 	wc = wa + wb;
   850 	if (wc > a->maxwds)
   851 		k++;
   852 	c = Balloc(k);
   853 	for(x = c->x, xa = x + wc; x < xa; x++)
   854 		*x = 0;
   855 	xa = a->x;
   856 	xae = xa + wa;
   857 	xb = b->x;
   858 	xbe = xb + wb;
   859 	xc0 = c->x;
   860 #ifdef ULLong
   861 	for(; xb < xbe; xc0++) {
   862 		if (y = *xb++) {
   863 			x = xa;
   864 			xc = xc0;
   865 			carry = 0;
   866 			do {
   867 				z = *x++ * (ULLong)y + *xc + carry;
   868 				carry = z >> 32;
   869 				*xc++ = z & FFFFFFFF;
   870 				}
   871 				while(x < xae);
   872 			*xc = carry;
   873 			}
   874 		}
   875 #else
   876 #ifdef Pack_32
   877 	for(; xb < xbe; xb++, xc0++) {
   878 		if (y = *xb & 0xffff) {
   879 			x = xa;
   880 			xc = xc0;
   881 			carry = 0;
   882 			do {
   883 				z = (*x & 0xffff) * y + (*xc & 0xffff) + carry;
   884 				carry = z >> 16;
   885 				z2 = (*x++ >> 16) * y + (*xc >> 16) + carry;
   886 				carry = z2 >> 16;
   887 				Storeinc(xc, z2, z);
   888 				}
   889 				while(x < xae);
   890 			*xc = carry;
   891 			}
   892 		if (y = *xb >> 16) {
   893 			x = xa;
   894 			xc = xc0;
   895 			carry = 0;
   896 			z2 = *xc;
   897 			do {
   898 				z = (*x & 0xffff) * y + (*xc >> 16) + carry;
   899 				carry = z >> 16;
   900 				Storeinc(xc, z, z2);
   901 				z2 = (*x++ >> 16) * y + (*xc & 0xffff) + carry;
   902 				carry = z2 >> 16;
   903 				}
   904 				while(x < xae);
   905 			*xc = z2;
   906 			}
   907 		}
   908 #else
   909 	for(; xb < xbe; xc0++) {
   910 		if (y = *xb++) {
   911 			x = xa;
   912 			xc = xc0;
   913 			carry = 0;
   914 			do {
   915 				z = *x++ * y + *xc + carry;
   916 				carry = z >> 16;
   917 				*xc++ = z & 0xffff;
   918 				}
   919 				while(x < xae);
   920 			*xc = carry;
   921 			}
   922 		}
   923 #endif
   924 #endif
   925 	for(xc0 = c->x, xc = xc0 + wc; wc > 0 && !*--xc; --wc) ;
   926 	c->wds = wc;
   927 	return c;
   928 	}
   930  static Bigint *p5s;
   932  static Bigint *
   933 pow5mult
   934 #ifdef KR_headers
   935 	(b, k) Bigint *b; int k;
   936 #else
   937 	(Bigint *b, int k)
   938 #endif
   939 {
   940 	Bigint *b1, *p5, *p51;
   941 	int i;
   942 	static int p05[3] = { 5, 25, 125 };
   944 	if (i = k & 3)
   945 		b = multadd(b, p05[i-1], 0);
   947 	if (!(k >>= 2))
   948 		return b;
   949 	if (!(p5 = p5s)) {
   950 		/* first time */
   951 #ifdef MULTIPLE_THREADS
   952 		ACQUIRE_DTOA_LOCK(1);
   953 		if (!(p5 = p5s)) {
   954 			p5 = p5s = i2b(625);
   955 			p5->next = 0;
   956 			}
   957 		FREE_DTOA_LOCK(1);
   958 #else
   959 		p5 = p5s = i2b(625);
   960 		p5->next = 0;
   961 #endif
   962 		}
   963 	for(;;) {
   964 		if (k & 1) {
   965 			b1 = mult(b, p5);
   966 			Bfree(b);
   967 			b = b1;
   968 			}
   969 		if (!(k >>= 1))
   970 			break;
   971 		if (!(p51 = p5->next)) {
   972 #ifdef MULTIPLE_THREADS
   973 			ACQUIRE_DTOA_LOCK(1);
   974 			if (!(p51 = p5->next)) {
   975 				p51 = p5->next = mult(p5,p5);
   976 				p51->next = 0;
   977 				}
   978 			FREE_DTOA_LOCK(1);
   979 #else
   980 			p51 = p5->next = mult(p5,p5);
   981 			p51->next = 0;
   982 #endif
   983 			}
   984 		p5 = p51;
   985 		}
   986 	return b;
   987 	}
   989  static Bigint *
   990 lshift
   991 #ifdef KR_headers
   992 	(b, k) Bigint *b; int k;
   993 #else
   994 	(Bigint *b, int k)
   995 #endif
   996 {
   997 	int i, k1, n, n1;
   998 	Bigint *b1;
   999 	ULong *x, *x1, *xe, z;
  1001 #ifdef Pack_32
  1002 	n = k >> 5;
  1003 #else
  1004 	n = k >> 4;
  1005 #endif
  1006 	k1 = b->k;
  1007 	n1 = n + b->wds + 1;
  1008 	for(i = b->maxwds; n1 > i; i <<= 1)
  1009 		k1++;
  1010 	b1 = Balloc(k1);
  1011 	x1 = b1->x;
  1012 	for(i = 0; i < n; i++)
  1013 		*x1++ = 0;
  1014 	x = b->x;
  1015 	xe = x + b->wds;
  1016 #ifdef Pack_32
  1017 	if (k &= 0x1f) {
  1018 		k1 = 32 - k;
  1019 		z = 0;
  1020 		do {
  1021 			*x1++ = *x << k | z;
  1022 			z = *x++ >> k1;
  1024 			while(x < xe);
  1025 		if (*x1 = z)
  1026 			++n1;
  1028 #else
  1029 	if (k &= 0xf) {
  1030 		k1 = 16 - k;
  1031 		z = 0;
  1032 		do {
  1033 			*x1++ = *x << k  & 0xffff | z;
  1034 			z = *x++ >> k1;
  1036 			while(x < xe);
  1037 		if (*x1 = z)
  1038 			++n1;
  1040 #endif
  1041 	else do
  1042 		*x1++ = *x++;
  1043 		while(x < xe);
  1044 	b1->wds = n1 - 1;
  1045 	Bfree(b);
  1046 	return b1;
  1049  static int
  1050 cmp
  1051 #ifdef KR_headers
  1052 	(a, b) Bigint *a, *b;
  1053 #else
  1054 	(Bigint *a, Bigint *b)
  1055 #endif
  1057 	ULong *xa, *xa0, *xb, *xb0;
  1058 	int i, j;
  1060 	i = a->wds;
  1061 	j = b->wds;
  1062 #ifdef DEBUG
  1063 	if (i > 1 && !a->x[i-1])
  1064 		Bug("cmp called with a->x[a->wds-1] == 0");
  1065 	if (j > 1 && !b->x[j-1])
  1066 		Bug("cmp called with b->x[b->wds-1] == 0");
  1067 #endif
  1068 	if (i -= j)
  1069 		return i;
  1070 	xa0 = a->x;
  1071 	xa = xa0 + j;
  1072 	xb0 = b->x;
  1073 	xb = xb0 + j;
  1074 	for(;;) {
  1075 		if (*--xa != *--xb)
  1076 			return *xa < *xb ? -1 : 1;
  1077 		if (xa <= xa0)
  1078 			break;
  1080 	return 0;
  1083  static Bigint *
  1084 diff
  1085 #ifdef KR_headers
  1086 	(a, b) Bigint *a, *b;
  1087 #else
  1088 	(Bigint *a, Bigint *b)
  1089 #endif
  1091 	Bigint *c;
  1092 	int i, wa, wb;
  1093 	ULong *xa, *xae, *xb, *xbe, *xc;
  1094 #ifdef ULLong
  1095 	ULLong borrow, y;
  1096 #else
  1097 	ULong borrow, y;
  1098 #ifdef Pack_32
  1099 	ULong z;
  1100 #endif
  1101 #endif
  1103 	i = cmp(a,b);
  1104 	if (!i) {
  1105 		c = Balloc(0);
  1106 		c->wds = 1;
  1107 		c->x[0] = 0;
  1108 		return c;
  1110 	if (i < 0) {
  1111 		c = a;
  1112 		a = b;
  1113 		b = c;
  1114 		i = 1;
  1116 	else
  1117 		i = 0;
  1118 	c = Balloc(a->k);
  1119 	c->sign = i;
  1120 	wa = a->wds;
  1121 	xa = a->x;
  1122 	xae = xa + wa;
  1123 	wb = b->wds;
  1124 	xb = b->x;
  1125 	xbe = xb + wb;
  1126 	xc = c->x;
  1127 	borrow = 0;
  1128 #ifdef ULLong
  1129 	do {
  1130 		y = (ULLong)*xa++ - *xb++ - borrow;
  1131 		borrow = y >> 32 & (ULong)1;
  1132 		*xc++ = y & FFFFFFFF;
  1134 		while(xb < xbe);
  1135 	while(xa < xae) {
  1136 		y = *xa++ - borrow;
  1137 		borrow = y >> 32 & (ULong)1;
  1138 		*xc++ = y & FFFFFFFF;
  1140 #else
  1141 #ifdef Pack_32
  1142 	do {
  1143 		y = (*xa & 0xffff) - (*xb & 0xffff) - borrow;
  1144 		borrow = (y & 0x10000) >> 16;
  1145 		z = (*xa++ >> 16) - (*xb++ >> 16) - borrow;
  1146 		borrow = (z & 0x10000) >> 16;
  1147 		Storeinc(xc, z, y);
  1149 		while(xb < xbe);
  1150 	while(xa < xae) {
  1151 		y = (*xa & 0xffff) - borrow;
  1152 		borrow = (y & 0x10000) >> 16;
  1153 		z = (*xa++ >> 16) - borrow;
  1154 		borrow = (z & 0x10000) >> 16;
  1155 		Storeinc(xc, z, y);
  1157 #else
  1158 	do {
  1159 		y = *xa++ - *xb++ - borrow;
  1160 		borrow = (y & 0x10000) >> 16;
  1161 		*xc++ = y & 0xffff;
  1163 		while(xb < xbe);
  1164 	while(xa < xae) {
  1165 		y = *xa++ - borrow;
  1166 		borrow = (y & 0x10000) >> 16;
  1167 		*xc++ = y & 0xffff;
  1169 #endif
  1170 #endif
  1171 	while(!*--xc)
  1172 		wa--;
  1173 	c->wds = wa;
  1174 	return c;
  1177  static double
  1178 ulp
  1179 #ifdef KR_headers
  1180 	(dx) double dx;
  1181 #else
  1182 	(double dx)
  1183 #endif
  1185 	register Long L;
  1186 	U x, a;
  1188 	dval(x) = dx;
  1189 	L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1;
  1190 #ifndef Avoid_Underflow
  1191 #ifndef Sudden_Underflow
  1192 	if (L > 0) {
  1193 #endif
  1194 #endif
  1195 #ifdef IBM
  1196 		L |= Exp_msk1 >> 4;
  1197 #endif
  1198 		word0(a) = L;
  1199 		word1(a) = 0;
  1200 #ifndef Avoid_Underflow
  1201 #ifndef Sudden_Underflow
  1203 	else {
  1204 		L = -L >> Exp_shift;
  1205 		if (L < Exp_shift) {
  1206 			word0(a) = 0x80000 >> L;
  1207 			word1(a) = 0;
  1209 		else {
  1210 			word0(a) = 0;
  1211 			L -= Exp_shift;
  1212 			word1(a) = L >= 31 ? 1 : 1 << 31 - L;
  1215 #endif
  1216 #endif
  1217 	return dval(a);
  1220  static double
  1221 b2d
  1222 #ifdef KR_headers
  1223 	(a, e) Bigint *a; int *e;
  1224 #else
  1225 	(Bigint *a, int *e)
  1226 #endif
  1228 	ULong *xa, *xa0, w, y, z;
  1229 	int k;
  1230 	U d;
  1231 #ifdef VAX
  1232 	ULong d0, d1;
  1233 #else
  1234 #define d0 word0(d)
  1235 #define d1 word1(d)
  1236 #endif
  1238 	xa0 = a->x;
  1239 	xa = xa0 + a->wds;
  1240 	y = *--xa;
  1241 #ifdef DEBUG
  1242 	if (!y) Bug("zero y in b2d");
  1243 #endif
  1244 	k = hi0bits(y);
  1245 	*e = 32 - k;
  1246 #ifdef Pack_32
  1247 	if (k < Ebits) {
  1248 		d0 = Exp_1 | y >> Ebits - k;
  1249 		w = xa > xa0 ? *--xa : 0;
  1250 		d1 = y << (32-Ebits) + k | w >> Ebits - k;
  1251 		goto ret_d;
  1253 	z = xa > xa0 ? *--xa : 0;
  1254 	if (k -= Ebits) {
  1255 		d0 = Exp_1 | y << k | z >> 32 - k;
  1256 		y = xa > xa0 ? *--xa : 0;
  1257 		d1 = z << k | y >> 32 - k;
  1259 	else {
  1260 		d0 = Exp_1 | y;
  1261 		d1 = z;
  1263 #else
  1264 	if (k < Ebits + 16) {
  1265 		z = xa > xa0 ? *--xa : 0;
  1266 		d0 = Exp_1 | y << k - Ebits | z >> Ebits + 16 - k;
  1267 		w = xa > xa0 ? *--xa : 0;
  1268 		y = xa > xa0 ? *--xa : 0;
  1269 		d1 = z << k + 16 - Ebits | w << k - Ebits | y >> 16 + Ebits - k;
  1270 		goto ret_d;
  1272 	z = xa > xa0 ? *--xa : 0;
  1273 	w = xa > xa0 ? *--xa : 0;
  1274 	k -= Ebits + 16;
  1275 	d0 = Exp_1 | y << k + 16 | z << k | w >> 16 - k;
  1276 	y = xa > xa0 ? *--xa : 0;
  1277 	d1 = w << k + 16 | y << k;
  1278 #endif
  1279  ret_d:
  1280 #ifdef VAX
  1281 	word0(d) = d0 >> 16 | d0 << 16;
  1282 	word1(d) = d1 >> 16 | d1 << 16;
  1283 #else
  1284 #undef d0
  1285 #undef d1
  1286 #endif
  1287 	return dval(d);
  1290  static Bigint *
  1291 d2b
  1292 #ifdef KR_headers
  1293 	(dd, e, bits) double dd; int *e, *bits;
  1294 #else
  1295 	(double dd, int *e, int *bits)
  1296 #endif
  1298 	U d;
  1299 	Bigint *b;
  1300 	int de, k;
  1301 	ULong *x, y, z;
  1302 #ifndef Sudden_Underflow
  1303 	int i;
  1304 #endif
  1305 #ifdef VAX
  1306 	ULong d0, d1;
  1307 #endif
  1309 	dval(d) = dd;
  1310 #ifdef VAX
  1311 	d0 = word0(d) >> 16 | word0(d) << 16;
  1312 	d1 = word1(d) >> 16 | word1(d) << 16;
  1313 #else
  1314 #define d0 word0(d)
  1315 #define d1 word1(d)
  1316 #endif
  1318 #ifdef Pack_32
  1319 	b = Balloc(1);
  1320 #else
  1321 	b = Balloc(2);
  1322 #endif
  1323 	x = b->x;
  1325 	z = d0 & Frac_mask;
  1326 	d0 &= 0x7fffffff;	/* clear sign bit, which we ignore */
  1327 #ifdef Sudden_Underflow
  1328 	de = (int)(d0 >> Exp_shift);
  1329 #ifndef IBM
  1330 	z |= Exp_msk11;
  1331 #endif
  1332 #else
  1333 	if (de = (int)(d0 >> Exp_shift))
  1334 		z |= Exp_msk1;
  1335 #endif
  1336 #ifdef Pack_32
  1337 	if (y = d1) {
  1338 		if (k = lo0bits(&y)) {
  1339 			x[0] = y | z << 32 - k;
  1340 			z >>= k;
  1342 		else
  1343 			x[0] = y;
  1344 #ifndef Sudden_Underflow
  1345 		i =
  1346 #endif
  1347 		    b->wds = (x[1] = z) ? 2 : 1;
  1349 	else {
  1350 		k = lo0bits(&z);
  1351 		x[0] = z;
  1352 #ifndef Sudden_Underflow
  1353 		i =
  1354 #endif
  1355 		    b->wds = 1;
  1356 		k += 32;
  1358 #else
  1359 	if (y = d1) {
  1360 		if (k = lo0bits(&y))
  1361 			if (k >= 16) {
  1362 				x[0] = y | z << 32 - k & 0xffff;
  1363 				x[1] = z >> k - 16 & 0xffff;
  1364 				x[2] = z >> k;
  1365 				i = 2;
  1367 			else {
  1368 				x[0] = y & 0xffff;
  1369 				x[1] = y >> 16 | z << 16 - k & 0xffff;
  1370 				x[2] = z >> k & 0xffff;
  1371 				x[3] = z >> k+16;
  1372 				i = 3;
  1374 		else {
  1375 			x[0] = y & 0xffff;
  1376 			x[1] = y >> 16;
  1377 			x[2] = z & 0xffff;
  1378 			x[3] = z >> 16;
  1379 			i = 3;
  1382 	else {
  1383 #ifdef DEBUG
  1384 		if (!z)
  1385 			Bug("Zero passed to d2b");
  1386 #endif
  1387 		k = lo0bits(&z);
  1388 		if (k >= 16) {
  1389 			x[0] = z;
  1390 			i = 0;
  1392 		else {
  1393 			x[0] = z & 0xffff;
  1394 			x[1] = z >> 16;
  1395 			i = 1;
  1397 		k += 32;
  1399 	while(!x[i])
  1400 		--i;
  1401 	b->wds = i + 1;
  1402 #endif
  1403 #ifndef Sudden_Underflow
  1404 	if (de) {
  1405 #endif
  1406 #ifdef IBM
  1407 		*e = (de - Bias - (P-1) << 2) + k;
  1408 		*bits = 4*P + 8 - k - hi0bits(word0(d) & Frac_mask);
  1409 #else
  1410 		*e = de - Bias - (P-1) + k;
  1411 		*bits = P - k;
  1412 #endif
  1413 #ifndef Sudden_Underflow
  1415 	else {
  1416 		*e = de - Bias - (P-1) + 1 + k;
  1417 #ifdef Pack_32
  1418 		*bits = 32*i - hi0bits(x[i-1]);
  1419 #else
  1420 		*bits = (i+2)*16 - hi0bits(x[i]);
  1421 #endif
  1423 #endif
  1424 	return b;
  1426 #undef d0
  1427 #undef d1
  1429  static double
  1430 ratio
  1431 #ifdef KR_headers
  1432 	(a, b) Bigint *a, *b;
  1433 #else
  1434 	(Bigint *a, Bigint *b)
  1435 #endif
  1437 	U da, db;
  1438 	int k, ka, kb;
  1440 	dval(da) = b2d(a, &ka);
  1441 	dval(db) = b2d(b, &kb);
  1442 #ifdef Pack_32
  1443 	k = ka - kb + 32*(a->wds - b->wds);
  1444 #else
  1445 	k = ka - kb + 16*(a->wds - b->wds);
  1446 #endif
  1447 #ifdef IBM
  1448 	if (k > 0) {
  1449 		word0(da) += (k >> 2)*Exp_msk1;
  1450 		if (k &= 3)
  1451 			dval(da) *= 1 << k;
  1453 	else {
  1454 		k = -k;
  1455 		word0(db) += (k >> 2)*Exp_msk1;
  1456 		if (k &= 3)
  1457 			dval(db) *= 1 << k;
  1459 #else
  1460 	if (k > 0)
  1461 		word0(da) += k*Exp_msk1;
  1462 	else {
  1463 		k = -k;
  1464 		word0(db) += k*Exp_msk1;
  1466 #endif
  1467 	return dval(da) / dval(db);
  1470  static CONST double
  1471 tens[] = {
  1472 		1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
  1473 		1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
  1474 		1e20, 1e21, 1e22
  1475 #ifdef VAX
  1476 		, 1e23, 1e24
  1477 #endif
  1478 		};
  1480  static CONST double
  1481 #ifdef IEEE_Arith
  1482 bigtens[] = { 1e16, 1e32, 1e64, 1e128, 1e256 };
  1483 static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128,
  1484 #ifdef Avoid_Underflow
  1485 		9007199254740992.*9007199254740992.e-256
  1486 		/* = 2^106 * 1e-53 */
  1487 #else
  1488 		1e-256
  1489 #endif
  1490 		};
  1491 /* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */
  1492 /* flag unnecessarily.  It leads to a song and dance at the end of strtod. */
  1493 #define Scale_Bit 0x10
  1494 #define n_bigtens 5
  1495 #else
  1496 #ifdef IBM
  1497 bigtens[] = { 1e16, 1e32, 1e64 };
  1498 static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64 };
  1499 #define n_bigtens 3
  1500 #else
  1501 bigtens[] = { 1e16, 1e32 };
  1502 static CONST double tinytens[] = { 1e-16, 1e-32 };
  1503 #define n_bigtens 2
  1504 #endif
  1505 #endif
  1507 #ifndef IEEE_Arith
  1508 #undef INFNAN_CHECK
  1509 #endif
  1511 #ifdef INFNAN_CHECK
  1513 #ifndef NAN_WORD0
  1514 #define NAN_WORD0 0x7ff80000
  1515 #endif
  1517 #ifndef NAN_WORD1
  1518 #define NAN_WORD1 0
  1519 #endif
  1521  static int
  1522 match
  1523 #ifdef KR_headers
  1524 	(sp, t) char **sp, *t;
  1525 #else
  1526 	(CONST char **sp, char *t)
  1527 #endif
  1529 	int c, d;
  1530 	CONST char *s = *sp;
  1532 	while(d = *t++) {
  1533 		if ((c = *++s) >= 'A' && c <= 'Z')
  1534 			c += 'a' - 'A';
  1535 		if (c != d)
  1536 			return 0;
  1538 	*sp = s + 1;
  1539 	return 1;
  1542 #ifndef No_Hex_NaN
  1543  static void
  1544 hexnan
  1545 #ifdef KR_headers
  1546 	(rvp, sp) double *rvp; CONST char **sp;
  1547 #else
  1548 	(double *rvp, CONST char **sp)
  1549 #endif
  1551 	ULong c, x[2];
  1552 	CONST char *s;
  1553 	int havedig, udx0, xshift;
  1555 	x[0] = x[1] = 0;
  1556 	havedig = xshift = 0;
  1557 	udx0 = 1;
  1558 	s = *sp;
  1559 	while(c = *(CONST unsigned char*)++s) {
  1560 		if (c >= '0' && c <= '9')
  1561 			c -= '0';
  1562 		else if (c >= 'a' && c <= 'f')
  1563 			c += 10 - 'a';
  1564 		else if (c >= 'A' && c <= 'F')
  1565 			c += 10 - 'A';
  1566 		else if (c <= ' ') {
  1567 			if (udx0 && havedig) {
  1568 				udx0 = 0;
  1569 				xshift = 1;
  1571 			continue;
  1573 		else if (/*(*/ c == ')' && havedig) {
  1574 			*sp = s + 1;
  1575 			break;
  1577 		else
  1578 			return;	/* invalid form: don't change *sp */
  1579 		havedig = 1;
  1580 		if (xshift) {
  1581 			xshift = 0;
  1582 			x[0] = x[1];
  1583 			x[1] = 0;
  1585 		if (udx0)
  1586 			x[0] = (x[0] << 4) | (x[1] >> 28);
  1587 		x[1] = (x[1] << 4) | c;
  1589 	if ((x[0] &= 0xfffff) || x[1]) {
  1590 		word0(*rvp) = Exp_mask | x[0];
  1591 		word1(*rvp) = x[1];
  1594 #endif /*No_Hex_NaN*/
  1595 #endif /* INFNAN_CHECK */
  1597  PR_IMPLEMENT(double)
  1598 PR_strtod
  1599 #ifdef KR_headers
  1600 	(s00, se) CONST char *s00; char **se;
  1601 #else
  1602 	(CONST char *s00, char **se)
  1603 #endif
  1605 #ifdef Avoid_Underflow
  1606 	int scale;
  1607 #endif
  1608 	int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, dsign,
  1609 		 e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign;
  1610 	CONST char *s, *s0, *s1;
  1611 	double aadj, aadj1, adj;
  1612 	U aadj2, rv, rv0;
  1613 	Long L;
  1614 	ULong y, z;
  1615 	Bigint *bb, *bb1, *bd, *bd0, *bs, *delta;
  1616 #ifdef SET_INEXACT
  1617 	int inexact, oldinexact;
  1618 #endif
  1619 #ifdef Honor_FLT_ROUNDS
  1620 	int rounding;
  1621 #endif
  1622 #ifdef USE_LOCALE
  1623 	CONST char *s2;
  1624 #endif
  1626 	if (!_pr_initialized) _PR_ImplicitInitialization();
  1628 	sign = nz0 = nz = 0;
  1629 	dval(rv) = 0.;
  1630 	for(s = s00;;s++) switch(*s) {
  1631 		case '-':
  1632 			sign = 1;
  1633 			/* no break */
  1634 		case '+':
  1635 			if (*++s)
  1636 				goto break2;
  1637 			/* no break */
  1638 		case 0:
  1639 			goto ret0;
  1640 		case '\t':
  1641 		case '\n':
  1642 		case '\v':
  1643 		case '\f':
  1644 		case '\r':
  1645 		case ' ':
  1646 			continue;
  1647 		default:
  1648 			goto break2;
  1650  break2:
  1651 	if (*s == '0') {
  1652 		nz0 = 1;
  1653 		while(*++s == '0') ;
  1654 		if (!*s)
  1655 			goto ret;
  1657 	s0 = s;
  1658 	y = z = 0;
  1659 	for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)
  1660 		if (nd < 9)
  1661 			y = 10*y + c - '0';
  1662 		else if (nd < 16)
  1663 			z = 10*z + c - '0';
  1664 	nd0 = nd;
  1665 #ifdef USE_LOCALE
  1666 	s1 = localeconv()->decimal_point;
  1667 	if (c == *s1) {
  1668 		c = '.';
  1669 		if (*++s1) {
  1670 			s2 = s;
  1671 			for(;;) {
  1672 				if (*++s2 != *s1) {
  1673 					c = 0;
  1674 					break;
  1676 				if (!*++s1) {
  1677 					s = s2;
  1678 					break;
  1683 #endif
  1684 	if (c == '.') {
  1685 		c = *++s;
  1686 		if (!nd) {
  1687 			for(; c == '0'; c = *++s)
  1688 				nz++;
  1689 			if (c > '0' && c <= '9') {
  1690 				s0 = s;
  1691 				nf += nz;
  1692 				nz = 0;
  1693 				goto have_dig;
  1695 			goto dig_done;
  1697 		for(; c >= '0' && c <= '9'; c = *++s) {
  1698  have_dig:
  1699 			nz++;
  1700 			if (c -= '0') {
  1701 				nf += nz;
  1702 				for(i = 1; i < nz; i++)
  1703 					if (nd++ < 9)
  1704 						y *= 10;
  1705 					else if (nd <= DBL_DIG + 1)
  1706 						z *= 10;
  1707 				if (nd++ < 9)
  1708 					y = 10*y + c;
  1709 				else if (nd <= DBL_DIG + 1)
  1710 					z = 10*z + c;
  1711 				nz = 0;
  1715  dig_done:
  1716 	if (nd > 64 * 1024)
  1717 		goto ret0;
  1718 	e = 0;
  1719 	if (c == 'e' || c == 'E') {
  1720 		if (!nd && !nz && !nz0) {
  1721 			goto ret0;
  1723 		s00 = s;
  1724 		esign = 0;
  1725 		switch(c = *++s) {
  1726 			case '-':
  1727 				esign = 1;
  1728 			case '+':
  1729 				c = *++s;
  1731 		if (c >= '0' && c <= '9') {
  1732 			while(c == '0')
  1733 				c = *++s;
  1734 			if (c > '0' && c <= '9') {
  1735 				L = c - '0';
  1736 				s1 = s;
  1737 				while((c = *++s) >= '0' && c <= '9')
  1738 					L = 10*L + c - '0';
  1739 				if (s - s1 > 8 || L > 19999)
  1740 					/* Avoid confusion from exponents
  1741 					 * so large that e might overflow.
  1742 					 */
  1743 					e = 19999; /* safe for 16 bit ints */
  1744 				else
  1745 					e = (int)L;
  1746 				if (esign)
  1747 					e = -e;
  1749 			else
  1750 				e = 0;
  1752 		else
  1753 			s = s00;
  1755 	if (!nd) {
  1756 		if (!nz && !nz0) {
  1757 #ifdef INFNAN_CHECK
  1758 			/* Check for Nan and Infinity */
  1759 			switch(c) {
  1760 			  case 'i':
  1761 			  case 'I':
  1762 				if (match(&s,"nf")) {
  1763 					--s;
  1764 					if (!match(&s,"inity"))
  1765 						++s;
  1766 					word0(rv) = 0x7ff00000;
  1767 					word1(rv) = 0;
  1768 					goto ret;
  1770 				break;
  1771 			  case 'n':
  1772 			  case 'N':
  1773 				if (match(&s, "an")) {
  1774 					word0(rv) = NAN_WORD0;
  1775 					word1(rv) = NAN_WORD1;
  1776 #ifndef No_Hex_NaN
  1777 					if (*s == '(') /*)*/
  1778 						hexnan(&rv, &s);
  1779 #endif
  1780 					goto ret;
  1783 #endif /* INFNAN_CHECK */
  1784  ret0:
  1785 			s = s00;
  1786 			sign = 0;
  1788 		goto ret;
  1790 	e1 = e -= nf;
  1792 	/* Now we have nd0 digits, starting at s0, followed by a
  1793 	 * decimal point, followed by nd-nd0 digits.  The number we're
  1794 	 * after is the integer represented by those digits times
  1795 	 * 10**e */
  1797 	if (!nd0)
  1798 		nd0 = nd;
  1799 	k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;
  1800 	dval(rv) = y;
  1801 	if (k > 9) {
  1802 #ifdef SET_INEXACT
  1803 		if (k > DBL_DIG)
  1804 			oldinexact = get_inexact();
  1805 #endif
  1806 		dval(rv) = tens[k - 9] * dval(rv) + z;
  1808 	bd0 = 0;
  1809 	if (nd <= DBL_DIG
  1810 #ifndef RND_PRODQUOT
  1811 #ifndef Honor_FLT_ROUNDS
  1812 		&& Flt_Rounds == 1
  1813 #endif
  1814 #endif
  1815 			) {
  1816 		if (!e)
  1817 			goto ret;
  1818 		if (e > 0) {
  1819 			if (e <= Ten_pmax) {
  1820 #ifdef VAX
  1821 				goto vax_ovfl_check;
  1822 #else
  1823 #ifdef Honor_FLT_ROUNDS
  1824 				/* round correctly FLT_ROUNDS = 2 or 3 */
  1825 				if (sign) {
  1826 					rv = -rv;
  1827 					sign = 0;
  1829 #endif
  1830 				/* rv = */ rounded_product(dval(rv), tens[e]);
  1831 				goto ret;
  1832 #endif
  1834 			i = DBL_DIG - nd;
  1835 			if (e <= Ten_pmax + i) {
  1836 				/* A fancier test would sometimes let us do
  1837 				 * this for larger i values.
  1838 				 */
  1839 #ifdef Honor_FLT_ROUNDS
  1840 				/* round correctly FLT_ROUNDS = 2 or 3 */
  1841 				if (sign) {
  1842 					rv = -rv;
  1843 					sign = 0;
  1845 #endif
  1846 				e -= i;
  1847 				dval(rv) *= tens[i];
  1848 #ifdef VAX
  1849 				/* VAX exponent range is so narrow we must
  1850 				 * worry about overflow here...
  1851 				 */
  1852  vax_ovfl_check:
  1853 				word0(rv) -= P*Exp_msk1;
  1854 				/* rv = */ rounded_product(dval(rv), tens[e]);
  1855 				if ((word0(rv) & Exp_mask)
  1856 				 > Exp_msk1*(DBL_MAX_EXP+Bias-1-P))
  1857 					goto ovfl;
  1858 				word0(rv) += P*Exp_msk1;
  1859 #else
  1860 				/* rv = */ rounded_product(dval(rv), tens[e]);
  1861 #endif
  1862 				goto ret;
  1865 #ifndef Inaccurate_Divide
  1866 		else if (e >= -Ten_pmax) {
  1867 #ifdef Honor_FLT_ROUNDS
  1868 			/* round correctly FLT_ROUNDS = 2 or 3 */
  1869 			if (sign) {
  1870 				rv = -rv;
  1871 				sign = 0;
  1873 #endif
  1874 			/* rv = */ rounded_quotient(dval(rv), tens[-e]);
  1875 			goto ret;
  1877 #endif
  1879 	e1 += nd - k;
  1881 #ifdef IEEE_Arith
  1882 #ifdef SET_INEXACT
  1883 	inexact = 1;
  1884 	if (k <= DBL_DIG)
  1885 		oldinexact = get_inexact();
  1886 #endif
  1887 #ifdef Avoid_Underflow
  1888 	scale = 0;
  1889 #endif
  1890 #ifdef Honor_FLT_ROUNDS
  1891 	if ((rounding = Flt_Rounds) >= 2) {
  1892 		if (sign)
  1893 			rounding = rounding == 2 ? 0 : 2;
  1894 		else
  1895 			if (rounding != 2)
  1896 				rounding = 0;
  1898 #endif
  1899 #endif /*IEEE_Arith*/
  1901 	/* Get starting approximation = rv * 10**e1 */
  1903 	if (e1 > 0) {
  1904 		if (i = e1 & 15)
  1905 			dval(rv) *= tens[i];
  1906 		if (e1 &= ~15) {
  1907 			if (e1 > DBL_MAX_10_EXP) {
  1908  ovfl:
  1909 #ifndef NO_ERRNO
  1910 				PR_SetError(PR_RANGE_ERROR, 0);
  1911 #endif
  1912 				/* Can't trust HUGE_VAL */
  1913 #ifdef IEEE_Arith
  1914 #ifdef Honor_FLT_ROUNDS
  1915 				switch(rounding) {
  1916 				  case 0: /* toward 0 */
  1917 				  case 3: /* toward -infinity */
  1918 					word0(rv) = Big0;
  1919 					word1(rv) = Big1;
  1920 					break;
  1921 				  default:
  1922 					word0(rv) = Exp_mask;
  1923 					word1(rv) = 0;
  1925 #else /*Honor_FLT_ROUNDS*/
  1926 				word0(rv) = Exp_mask;
  1927 				word1(rv) = 0;
  1928 #endif /*Honor_FLT_ROUNDS*/
  1929 #ifdef SET_INEXACT
  1930 				/* set overflow bit */
  1931 				dval(rv0) = 1e300;
  1932 				dval(rv0) *= dval(rv0);
  1933 #endif
  1934 #else /*IEEE_Arith*/
  1935 				word0(rv) = Big0;
  1936 				word1(rv) = Big1;
  1937 #endif /*IEEE_Arith*/
  1938 				if (bd0)
  1939 					goto retfree;
  1940 				goto ret;
  1942 			e1 >>= 4;
  1943 			for(j = 0; e1 > 1; j++, e1 >>= 1)
  1944 				if (e1 & 1)
  1945 					dval(rv) *= bigtens[j];
  1946 		/* The last multiplication could overflow. */
  1947 			word0(rv) -= P*Exp_msk1;
  1948 			dval(rv) *= bigtens[j];
  1949 			if ((z = word0(rv) & Exp_mask)
  1950 			 > Exp_msk1*(DBL_MAX_EXP+Bias-P))
  1951 				goto ovfl;
  1952 			if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) {
  1953 				/* set to largest number */
  1954 				/* (Can't trust DBL_MAX) */
  1955 				word0(rv) = Big0;
  1956 				word1(rv) = Big1;
  1958 			else
  1959 				word0(rv) += P*Exp_msk1;
  1962 	else if (e1 < 0) {
  1963 		e1 = -e1;
  1964 		if (i = e1 & 15)
  1965 			dval(rv) /= tens[i];
  1966 		if (e1 >>= 4) {
  1967 			if (e1 >= 1 << n_bigtens)
  1968 				goto undfl;
  1969 #ifdef Avoid_Underflow
  1970 			if (e1 & Scale_Bit)
  1971 				scale = 2*P;
  1972 			for(j = 0; e1 > 0; j++, e1 >>= 1)
  1973 				if (e1 & 1)
  1974 					dval(rv) *= tinytens[j];
  1975 			if (scale && (j = 2*P + 1 - ((word0(rv) & Exp_mask)
  1976 						>> Exp_shift)) > 0) {
  1977 				/* scaled rv is denormal; zap j low bits */
  1978 				if (j >= 32) {
  1979 					word1(rv) = 0;
  1980 					if (j >= 53)
  1981 					 word0(rv) = (P+2)*Exp_msk1;
  1982 					else
  1983 					 word0(rv) &= 0xffffffff << j-32;
  1985 				else
  1986 					word1(rv) &= 0xffffffff << j;
  1988 #else
  1989 			for(j = 0; e1 > 1; j++, e1 >>= 1)
  1990 				if (e1 & 1)
  1991 					dval(rv) *= tinytens[j];
  1992 			/* The last multiplication could underflow. */
  1993 			dval(rv0) = dval(rv);
  1994 			dval(rv) *= tinytens[j];
  1995 			if (!dval(rv)) {
  1996 				dval(rv) = 2.*dval(rv0);
  1997 				dval(rv) *= tinytens[j];
  1998 #endif
  1999 				if (!dval(rv)) {
  2000  undfl:
  2001 					dval(rv) = 0.;
  2002 #ifndef NO_ERRNO
  2003 					PR_SetError(PR_RANGE_ERROR, 0);
  2004 #endif
  2005 					if (bd0)
  2006 						goto retfree;
  2007 					goto ret;
  2009 #ifndef Avoid_Underflow
  2010 				word0(rv) = Tiny0;
  2011 				word1(rv) = Tiny1;
  2012 				/* The refinement below will clean
  2013 				 * this approximation up.
  2014 				 */
  2016 #endif
  2020 	/* Now the hard part -- adjusting rv to the correct value.*/
  2022 	/* Put digits into bd: true value = bd * 10^e */
  2024 	bd0 = s2b(s0, nd0, nd, y);
  2026 	for(;;) {
  2027 		bd = Balloc(bd0->k);
  2028 		Bcopy(bd, bd0);
  2029 		bb = d2b(dval(rv), &bbe, &bbbits);	/* rv = bb * 2^bbe */
  2030 		bs = i2b(1);
  2032 		if (e >= 0) {
  2033 			bb2 = bb5 = 0;
  2034 			bd2 = bd5 = e;
  2036 		else {
  2037 			bb2 = bb5 = -e;
  2038 			bd2 = bd5 = 0;
  2040 		if (bbe >= 0)
  2041 			bb2 += bbe;
  2042 		else
  2043 			bd2 -= bbe;
  2044 		bs2 = bb2;
  2045 #ifdef Honor_FLT_ROUNDS
  2046 		if (rounding != 1)
  2047 			bs2++;
  2048 #endif
  2049 #ifdef Avoid_Underflow
  2050 		j = bbe - scale;
  2051 		i = j + bbbits - 1;	/* logb(rv) */
  2052 		if (i < Emin)	/* denormal */
  2053 			j += P - Emin;
  2054 		else
  2055 			j = P + 1 - bbbits;
  2056 #else /*Avoid_Underflow*/
  2057 #ifdef Sudden_Underflow
  2058 #ifdef IBM
  2059 		j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3);
  2060 #else
  2061 		j = P + 1 - bbbits;
  2062 #endif
  2063 #else /*Sudden_Underflow*/
  2064 		j = bbe;
  2065 		i = j + bbbits - 1;	/* logb(rv) */
  2066 		if (i < Emin)	/* denormal */
  2067 			j += P - Emin;
  2068 		else
  2069 			j = P + 1 - bbbits;
  2070 #endif /*Sudden_Underflow*/
  2071 #endif /*Avoid_Underflow*/
  2072 		bb2 += j;
  2073 		bd2 += j;
  2074 #ifdef Avoid_Underflow
  2075 		bd2 += scale;
  2076 #endif
  2077 		i = bb2 < bd2 ? bb2 : bd2;
  2078 		if (i > bs2)
  2079 			i = bs2;
  2080 		if (i > 0) {
  2081 			bb2 -= i;
  2082 			bd2 -= i;
  2083 			bs2 -= i;
  2085 		if (bb5 > 0) {
  2086 			bs = pow5mult(bs, bb5);
  2087 			bb1 = mult(bs, bb);
  2088 			Bfree(bb);
  2089 			bb = bb1;
  2091 		if (bb2 > 0)
  2092 			bb = lshift(bb, bb2);
  2093 		if (bd5 > 0)
  2094 			bd = pow5mult(bd, bd5);
  2095 		if (bd2 > 0)
  2096 			bd = lshift(bd, bd2);
  2097 		if (bs2 > 0)
  2098 			bs = lshift(bs, bs2);
  2099 		delta = diff(bb, bd);
  2100 		dsign = delta->sign;
  2101 		delta->sign = 0;
  2102 		i = cmp(delta, bs);
  2103 #ifdef Honor_FLT_ROUNDS
  2104 		if (rounding != 1) {
  2105 			if (i < 0) {
  2106 				/* Error is less than an ulp */
  2107 				if (!delta->x[0] && delta->wds <= 1) {
  2108 					/* exact */
  2109 #ifdef SET_INEXACT
  2110 					inexact = 0;
  2111 #endif
  2112 					break;
  2114 				if (rounding) {
  2115 					if (dsign) {
  2116 						adj = 1.;
  2117 						goto apply_adj;
  2120 				else if (!dsign) {
  2121 					adj = -1.;
  2122 					if (!word1(rv)
  2123 					 && !(word0(rv) & Frac_mask)) {
  2124 						y = word0(rv) & Exp_mask;
  2125 #ifdef Avoid_Underflow
  2126 						if (!scale || y > 2*P*Exp_msk1)
  2127 #else
  2128 						if (y)
  2129 #endif
  2131 						  delta = lshift(delta,Log2P);
  2132 						  if (cmp(delta, bs) <= 0)
  2133 							adj = -0.5;
  2136  apply_adj:
  2137 #ifdef Avoid_Underflow
  2138 					if (scale && (y = word0(rv) & Exp_mask)
  2139 						<= 2*P*Exp_msk1)
  2140 					  word0(adj) += (2*P+1)*Exp_msk1 - y;
  2141 #else
  2142 #ifdef Sudden_Underflow
  2143 					if ((word0(rv) & Exp_mask) <=
  2144 							P*Exp_msk1) {
  2145 						word0(rv) += P*Exp_msk1;
  2146 						dval(rv) += adj*ulp(dval(rv));
  2147 						word0(rv) -= P*Exp_msk1;
  2149 					else
  2150 #endif /*Sudden_Underflow*/
  2151 #endif /*Avoid_Underflow*/
  2152 					dval(rv) += adj*ulp(dval(rv));
  2154 				break;
  2156 			adj = ratio(delta, bs);
  2157 			if (adj < 1.)
  2158 				adj = 1.;
  2159 			if (adj <= 0x7ffffffe) {
  2160 				/* adj = rounding ? ceil(adj) : floor(adj); */
  2161 				y = adj;
  2162 				if (y != adj) {
  2163 					if (!((rounding>>1) ^ dsign))
  2164 						y++;
  2165 					adj = y;
  2168 #ifdef Avoid_Underflow
  2169 			if (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
  2170 				word0(adj) += (2*P+1)*Exp_msk1 - y;
  2171 #else
  2172 #ifdef Sudden_Underflow
  2173 			if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
  2174 				word0(rv) += P*Exp_msk1;
  2175 				adj *= ulp(dval(rv));
  2176 				if (dsign)
  2177 					dval(rv) += adj;
  2178 				else
  2179 					dval(rv) -= adj;
  2180 				word0(rv) -= P*Exp_msk1;
  2181 				goto cont;
  2183 #endif /*Sudden_Underflow*/
  2184 #endif /*Avoid_Underflow*/
  2185 			adj *= ulp(dval(rv));
  2186 			if (dsign)
  2187 				dval(rv) += adj;
  2188 			else
  2189 				dval(rv) -= adj;
  2190 			goto cont;
  2192 #endif /*Honor_FLT_ROUNDS*/
  2194 		if (i < 0) {
  2195 			/* Error is less than half an ulp -- check for
  2196 			 * special case of mantissa a power of two.
  2197 			 */
  2198 			if (dsign || word1(rv) || word0(rv) & Bndry_mask
  2199 #ifdef IEEE_Arith
  2200 #ifdef Avoid_Underflow
  2201 			 || (word0(rv) & Exp_mask) <= (2*P+1)*Exp_msk1
  2202 #else
  2203 			 || (word0(rv) & Exp_mask) <= Exp_msk1
  2204 #endif
  2205 #endif
  2206 				) {
  2207 #ifdef SET_INEXACT
  2208 				if (!delta->x[0] && delta->wds <= 1)
  2209 					inexact = 0;
  2210 #endif
  2211 				break;
  2213 			if (!delta->x[0] && delta->wds <= 1) {
  2214 				/* exact result */
  2215 #ifdef SET_INEXACT
  2216 				inexact = 0;
  2217 #endif
  2218 				break;
  2220 			delta = lshift(delta,Log2P);
  2221 			if (cmp(delta, bs) > 0)
  2222 				goto drop_down;
  2223 			break;
  2225 		if (i == 0) {
  2226 			/* exactly half-way between */
  2227 			if (dsign) {
  2228 				if ((word0(rv) & Bndry_mask1) == Bndry_mask1
  2229 				 &&  word1(rv) == (
  2230 #ifdef Avoid_Underflow
  2231 			(scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
  2232 		? (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) :
  2233 #endif
  2234 						   0xffffffff)) {
  2235 					/*boundary case -- increment exponent*/
  2236 					word0(rv) = (word0(rv) & Exp_mask)
  2237 						+ Exp_msk1
  2238 #ifdef IBM
  2239 						| Exp_msk1 >> 4
  2240 #endif
  2242 					word1(rv) = 0;
  2243 #ifdef Avoid_Underflow
  2244 					dsign = 0;
  2245 #endif
  2246 					break;
  2249 			else if (!(word0(rv) & Bndry_mask) && !word1(rv)) {
  2250  drop_down:
  2251 				/* boundary case -- decrement exponent */
  2252 #ifdef Sudden_Underflow /*{{*/
  2253 				L = word0(rv) & Exp_mask;
  2254 #ifdef IBM
  2255 				if (L <  Exp_msk1)
  2256 #else
  2257 #ifdef Avoid_Underflow
  2258 				if (L <= (scale ? (2*P+1)*Exp_msk1 : Exp_msk1))
  2259 #else
  2260 				if (L <= Exp_msk1)
  2261 #endif /*Avoid_Underflow*/
  2262 #endif /*IBM*/
  2263 					goto undfl;
  2264 				L -= Exp_msk1;
  2265 #else /*Sudden_Underflow}{*/
  2266 #ifdef Avoid_Underflow
  2267 				if (scale) {
  2268 					L = word0(rv) & Exp_mask;
  2269 					if (L <= (2*P+1)*Exp_msk1) {
  2270 						if (L > (P+2)*Exp_msk1)
  2271 							/* round even ==> */
  2272 							/* accept rv */
  2273 							break;
  2274 						/* rv = smallest denormal */
  2275 						goto undfl;
  2278 #endif /*Avoid_Underflow*/
  2279 				L = (word0(rv) & Exp_mask) - Exp_msk1;
  2280 #endif /*Sudden_Underflow}}*/
  2281 				word0(rv) = L | Bndry_mask1;
  2282 				word1(rv) = 0xffffffff;
  2283 #ifdef IBM
  2284 				goto cont;
  2285 #else
  2286 				break;
  2287 #endif
  2289 #ifndef ROUND_BIASED
  2290 			if (!(word1(rv) & LSB))
  2291 				break;
  2292 #endif
  2293 			if (dsign)
  2294 				dval(rv) += ulp(dval(rv));
  2295 #ifndef ROUND_BIASED
  2296 			else {
  2297 				dval(rv) -= ulp(dval(rv));
  2298 #ifndef Sudden_Underflow
  2299 				if (!dval(rv))
  2300 					goto undfl;
  2301 #endif
  2303 #ifdef Avoid_Underflow
  2304 			dsign = 1 - dsign;
  2305 #endif
  2306 #endif
  2307 			break;
  2309 		if ((aadj = ratio(delta, bs)) <= 2.) {
  2310 			if (dsign)
  2311 				aadj = aadj1 = 1.;
  2312 			else if (word1(rv) || word0(rv) & Bndry_mask) {
  2313 #ifndef Sudden_Underflow
  2314 				if (word1(rv) == Tiny1 && !word0(rv))
  2315 					goto undfl;
  2316 #endif
  2317 				aadj = 1.;
  2318 				aadj1 = -1.;
  2320 			else {
  2321 				/* special case -- power of FLT_RADIX to be */
  2322 				/* rounded down... */
  2324 				if (aadj < 2./FLT_RADIX)
  2325 					aadj = 1./FLT_RADIX;
  2326 				else
  2327 					aadj *= 0.5;
  2328 				aadj1 = -aadj;
  2331 		else {
  2332 			aadj *= 0.5;
  2333 			aadj1 = dsign ? aadj : -aadj;
  2334 #ifdef Check_FLT_ROUNDS
  2335 			switch(Rounding) {
  2336 				case 2: /* towards +infinity */
  2337 					aadj1 -= 0.5;
  2338 					break;
  2339 				case 0: /* towards 0 */
  2340 				case 3: /* towards -infinity */
  2341 					aadj1 += 0.5;
  2343 #else
  2344 			if (Flt_Rounds == 0)
  2345 				aadj1 += 0.5;
  2346 #endif /*Check_FLT_ROUNDS*/
  2348 		y = word0(rv) & Exp_mask;
  2350 		/* Check for overflow */
  2352 		if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
  2353 			dval(rv0) = dval(rv);
  2354 			word0(rv) -= P*Exp_msk1;
  2355 			adj = aadj1 * ulp(dval(rv));
  2356 			dval(rv) += adj;
  2357 			if ((word0(rv) & Exp_mask) >=
  2358 					Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
  2359 				if (word0(rv0) == Big0 && word1(rv0) == Big1)
  2360 					goto ovfl;
  2361 				word0(rv) = Big0;
  2362 				word1(rv) = Big1;
  2363 				goto cont;
  2365 			else
  2366 				word0(rv) += P*Exp_msk1;
  2368 		else {
  2369 #ifdef Avoid_Underflow
  2370 			if (scale && y <= 2*P*Exp_msk1) {
  2371 				if (aadj <= 0x7fffffff) {
  2372 					if ((z = aadj) <= 0)
  2373 						z = 1;
  2374 					aadj = z;
  2375 					aadj1 = dsign ? aadj : -aadj;
  2377 				dval(aadj2) = aadj1;
  2378 				word0(aadj2) += (2*P+1)*Exp_msk1 - y;
  2379 				aadj1 = dval(aadj2);
  2381 			adj = aadj1 * ulp(dval(rv));
  2382 			dval(rv) += adj;
  2383 #else
  2384 #ifdef Sudden_Underflow
  2385 			if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
  2386 				dval(rv0) = dval(rv);
  2387 				word0(rv) += P*Exp_msk1;
  2388 				adj = aadj1 * ulp(dval(rv));
  2389 				dval(rv) += adj;
  2390 #ifdef IBM
  2391 				if ((word0(rv) & Exp_mask) <  P*Exp_msk1)
  2392 #else
  2393 				if ((word0(rv) & Exp_mask) <= P*Exp_msk1)
  2394 #endif
  2396 					if (word0(rv0) == Tiny0
  2397 					 && word1(rv0) == Tiny1)
  2398 						goto undfl;
  2399 					word0(rv) = Tiny0;
  2400 					word1(rv) = Tiny1;
  2401 					goto cont;
  2403 				else
  2404 					word0(rv) -= P*Exp_msk1;
  2406 			else {
  2407 				adj = aadj1 * ulp(dval(rv));
  2408 				dval(rv) += adj;
  2410 #else /*Sudden_Underflow*/
  2411 			/* Compute adj so that the IEEE rounding rules will
  2412 			 * correctly round rv + adj in some half-way cases.
  2413 			 * If rv * ulp(rv) is denormalized (i.e.,
  2414 			 * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid
  2415 			 * trouble from bits lost to denormalization;
  2416 			 * example: 1.2e-307 .
  2417 			 */
  2418 			if (y <= (P-1)*Exp_msk1 && aadj > 1.) {
  2419 				aadj1 = (double)(int)(aadj + 0.5);
  2420 				if (!dsign)
  2421 					aadj1 = -aadj1;
  2423 			adj = aadj1 * ulp(dval(rv));
  2424 			dval(rv) += adj;
  2425 #endif /*Sudden_Underflow*/
  2426 #endif /*Avoid_Underflow*/
  2428 		z = word0(rv) & Exp_mask;
  2429 #ifndef SET_INEXACT
  2430 #ifdef Avoid_Underflow
  2431 		if (!scale)
  2432 #endif
  2433 		if (y == z) {
  2434 			/* Can we stop now? */
  2435 			L = (Long)aadj;
  2436 			aadj -= L;
  2437 			/* The tolerances below are conservative. */
  2438 			if (dsign || word1(rv) || word0(rv) & Bndry_mask) {
  2439 				if (aadj < .4999999 || aadj > .5000001)
  2440 					break;
  2442 			else if (aadj < .4999999/FLT_RADIX)
  2443 				break;
  2445 #endif
  2446  cont:
  2447 		Bfree(bb);
  2448 		Bfree(bd);
  2449 		Bfree(bs);
  2450 		Bfree(delta);
  2452 #ifdef SET_INEXACT
  2453 	if (inexact) {
  2454 		if (!oldinexact) {
  2455 			word0(rv0) = Exp_1 + (70 << Exp_shift);
  2456 			word1(rv0) = 0;
  2457 			dval(rv0) += 1.;
  2460 	else if (!oldinexact)
  2461 		clear_inexact();
  2462 #endif
  2463 #ifdef Avoid_Underflow
  2464 	if (scale) {
  2465 		word0(rv0) = Exp_1 - 2*P*Exp_msk1;
  2466 		word1(rv0) = 0;
  2467 		dval(rv) *= dval(rv0);
  2468 #ifndef NO_ERRNO
  2469 		/* try to avoid the bug of testing an 8087 register value */
  2470 		if (word0(rv) == 0 && word1(rv) == 0)
  2471 			PR_SetError(PR_RANGE_ERROR, 0);
  2472 #endif
  2474 #endif /* Avoid_Underflow */
  2475 #ifdef SET_INEXACT
  2476 	if (inexact && !(word0(rv) & Exp_mask)) {
  2477 		/* set underflow bit */
  2478 		dval(rv0) = 1e-300;
  2479 		dval(rv0) *= dval(rv0);
  2481 #endif
  2482  retfree:
  2483 	Bfree(bb);
  2484 	Bfree(bd);
  2485 	Bfree(bs);
  2486 	Bfree(bd0);
  2487 	Bfree(delta);
  2488  ret:
  2489 	if (se)
  2490 		*se = (char *)s;
  2491 	return sign ? -dval(rv) : dval(rv);
  2494  static int
  2495 quorem
  2496 #ifdef KR_headers
  2497 	(b, S) Bigint *b, *S;
  2498 #else
  2499 	(Bigint *b, Bigint *S)
  2500 #endif
  2502 	int n;
  2503 	ULong *bx, *bxe, q, *sx, *sxe;
  2504 #ifdef ULLong
  2505 	ULLong borrow, carry, y, ys;
  2506 #else
  2507 	ULong borrow, carry, y, ys;
  2508 #ifdef Pack_32
  2509 	ULong si, z, zs;
  2510 #endif
  2511 #endif
  2513 	n = S->wds;
  2514 #ifdef DEBUG
  2515 	/*debug*/ if (b->wds > n)
  2516 	/*debug*/	Bug("oversize b in quorem");
  2517 #endif
  2518 	if (b->wds < n)
  2519 		return 0;
  2520 	sx = S->x;
  2521 	sxe = sx + --n;
  2522 	bx = b->x;
  2523 	bxe = bx + n;
  2524 	q = *bxe / (*sxe + 1);	/* ensure q <= true quotient */
  2525 #ifdef DEBUG
  2526 	/*debug*/ if (q > 9)
  2527 	/*debug*/	Bug("oversized quotient in quorem");
  2528 #endif
  2529 	if (q) {
  2530 		borrow = 0;
  2531 		carry = 0;
  2532 		do {
  2533 #ifdef ULLong
  2534 			ys = *sx++ * (ULLong)q + carry;
  2535 			carry = ys >> 32;
  2536 			y = *bx - (ys & FFFFFFFF) - borrow;
  2537 			borrow = y >> 32 & (ULong)1;
  2538 			*bx++ = y & FFFFFFFF;
  2539 #else
  2540 #ifdef Pack_32
  2541 			si = *sx++;
  2542 			ys = (si & 0xffff) * q + carry;
  2543 			zs = (si >> 16) * q + (ys >> 16);
  2544 			carry = zs >> 16;
  2545 			y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
  2546 			borrow = (y & 0x10000) >> 16;
  2547 			z = (*bx >> 16) - (zs & 0xffff) - borrow;
  2548 			borrow = (z & 0x10000) >> 16;
  2549 			Storeinc(bx, z, y);
  2550 #else
  2551 			ys = *sx++ * q + carry;
  2552 			carry = ys >> 16;
  2553 			y = *bx - (ys & 0xffff) - borrow;
  2554 			borrow = (y & 0x10000) >> 16;
  2555 			*bx++ = y & 0xffff;
  2556 #endif
  2557 #endif
  2559 			while(sx <= sxe);
  2560 		if (!*bxe) {
  2561 			bx = b->x;
  2562 			while(--bxe > bx && !*bxe)
  2563 				--n;
  2564 			b->wds = n;
  2567 	if (cmp(b, S) >= 0) {
  2568 		q++;
  2569 		borrow = 0;
  2570 		carry = 0;
  2571 		bx = b->x;
  2572 		sx = S->x;
  2573 		do {
  2574 #ifdef ULLong
  2575 			ys = *sx++ + carry;
  2576 			carry = ys >> 32;
  2577 			y = *bx - (ys & FFFFFFFF) - borrow;
  2578 			borrow = y >> 32 & (ULong)1;
  2579 			*bx++ = y & FFFFFFFF;
  2580 #else
  2581 #ifdef Pack_32
  2582 			si = *sx++;
  2583 			ys = (si & 0xffff) + carry;
  2584 			zs = (si >> 16) + (ys >> 16);
  2585 			carry = zs >> 16;
  2586 			y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
  2587 			borrow = (y & 0x10000) >> 16;
  2588 			z = (*bx >> 16) - (zs & 0xffff) - borrow;
  2589 			borrow = (z & 0x10000) >> 16;
  2590 			Storeinc(bx, z, y);
  2591 #else
  2592 			ys = *sx++ + carry;
  2593 			carry = ys >> 16;
  2594 			y = *bx - (ys & 0xffff) - borrow;
  2595 			borrow = (y & 0x10000) >> 16;
  2596 			*bx++ = y & 0xffff;
  2597 #endif
  2598 #endif
  2600 			while(sx <= sxe);
  2601 		bx = b->x;
  2602 		bxe = bx + n;
  2603 		if (!*bxe) {
  2604 			while(--bxe > bx && !*bxe)
  2605 				--n;
  2606 			b->wds = n;
  2609 	return q;
  2612 #ifndef MULTIPLE_THREADS
  2613  static char *dtoa_result;
  2614 #endif
  2616  static char *
  2617 #ifdef KR_headers
  2618 rv_alloc(i) int i;
  2619 #else
  2620 rv_alloc(int i)
  2621 #endif
  2623 	int j, k, *r;
  2625 	j = sizeof(ULong);
  2626 	for(k = 0;
  2627 		sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i;
  2628 		j <<= 1)
  2629 			k++;
  2630 	r = (int*)Balloc(k);
  2631 	*r = k;
  2632 	return
  2633 #ifndef MULTIPLE_THREADS
  2634 	dtoa_result =
  2635 #endif
  2636 		(char *)(r+1);
  2639  static char *
  2640 #ifdef KR_headers
  2641 nrv_alloc(s, rve, n) char *s, **rve; int n;
  2642 #else
  2643 nrv_alloc(char *s, char **rve, int n)
  2644 #endif
  2646 	char *rv, *t;
  2648 	t = rv = rv_alloc(n);
  2649 	while(*t = *s++) t++;
  2650 	if (rve)
  2651 		*rve = t;
  2652 	return rv;
  2655 /* freedtoa(s) must be used to free values s returned by dtoa
  2656  * when MULTIPLE_THREADS is #defined.  It should be used in all cases,
  2657  * but for consistency with earlier versions of dtoa, it is optional
  2658  * when MULTIPLE_THREADS is not defined.
  2659  */
  2661  static void
  2662 #ifdef KR_headers
  2663 freedtoa(s) char *s;
  2664 #else
  2665 freedtoa(char *s)
  2666 #endif
  2668 	Bigint *b = (Bigint *)((int *)s - 1);
  2669 	b->maxwds = 1 << (b->k = *(int*)b);
  2670 	Bfree(b);
  2671 #ifndef MULTIPLE_THREADS
  2672 	if (s == dtoa_result)
  2673 		dtoa_result = 0;
  2674 #endif
  2677 /* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.
  2679  * Inspired by "How to Print Floating-Point Numbers Accurately" by
  2680  * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 112-126].
  2682  * Modifications:
  2683  *	1. Rather than iterating, we use a simple numeric overestimate
  2684  *	   to determine k = floor(log10(d)).  We scale relevant
  2685  *	   quantities using O(log2(k)) rather than O(k) multiplications.
  2686  *	2. For some modes > 2 (corresponding to ecvt and fcvt), we don't
  2687  *	   try to generate digits strictly left to right.  Instead, we
  2688  *	   compute with fewer bits and propagate the carry if necessary
  2689  *	   when rounding the final digit up.  This is often faster.
  2690  *	3. Under the assumption that input will be rounded nearest,
  2691  *	   mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22.
  2692  *	   That is, we allow equality in stopping tests when the
  2693  *	   round-nearest rule will give the same floating-point value
  2694  *	   as would satisfaction of the stopping test with strict
  2695  *	   inequality.
  2696  *	4. We remove common factors of powers of 2 from relevant
  2697  *	   quantities.
  2698  *	5. When converting floating-point integers less than 1e16,
  2699  *	   we use floating-point arithmetic rather than resorting
  2700  *	   to multiple-precision integers.
  2701  *	6. When asked to produce fewer than 15 digits, we first try
  2702  *	   to get by with floating-point arithmetic; we resort to
  2703  *	   multiple-precision integer arithmetic only if we cannot
  2704  *	   guarantee that the floating-point calculation has given
  2705  *	   the correctly rounded result.  For k requested digits and
  2706  *	   "uniformly" distributed input, the probability is
  2707  *	   something like 10^(k-15) that we must resort to the Long
  2708  *	   calculation.
  2709  */
  2711  static char *
  2712 dtoa
  2713 #ifdef KR_headers
  2714 	(dd, mode, ndigits, decpt, sign, rve)
  2715 	double dd; int mode, ndigits, *decpt, *sign; char **rve;
  2716 #else
  2717 	(double dd, int mode, int ndigits, int *decpt, int *sign, char **rve)
  2718 #endif
  2720  /*	Arguments ndigits, decpt, sign are similar to those
  2721 	of ecvt and fcvt; trailing zeros are suppressed from
  2722 	the returned string.  If not null, *rve is set to point
  2723 	to the end of the return value.  If d is +-Infinity or NaN,
  2724 	then *decpt is set to 9999.
  2726 	mode:
  2727 		0 ==> shortest string that yields d when read in
  2728 			and rounded to nearest.
  2729 		1 ==> like 0, but with Steele & White stopping rule;
  2730 			e.g. with IEEE P754 arithmetic , mode 0 gives
  2731 			1e23 whereas mode 1 gives 9.999999999999999e22.
  2732 		2 ==> max(1,ndigits) significant digits.  This gives a
  2733 			return value similar to that of ecvt, except
  2734 			that trailing zeros are suppressed.
  2735 		3 ==> through ndigits past the decimal point.  This
  2736 			gives a return value similar to that from fcvt,
  2737 			except that trailing zeros are suppressed, and
  2738 			ndigits can be negative.
  2739 		4,5 ==> similar to 2 and 3, respectively, but (in
  2740 			round-nearest mode) with the tests of mode 0 to
  2741 			possibly return a shorter string that rounds to d.
  2742 			With IEEE arithmetic and compilation with
  2743 			-DHonor_FLT_ROUNDS, modes 4 and 5 behave the same
  2744 			as modes 2 and 3 when FLT_ROUNDS != 1.
  2745 		6-9 ==> Debugging modes similar to mode - 4:  don't try
  2746 			fast floating-point estimate (if applicable).
  2748 		Values of mode other than 0-9 are treated as mode 0.
  2750 		Sufficient space is allocated to the return value
  2751 		to hold the suppressed trailing zeros.
  2752 	*/
  2754 	int bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1,
  2755 		j, j1, k, k0, k_check, leftright, m2, m5, s2, s5,
  2756 		spec_case, try_quick;
  2757 	Long L;
  2758 #ifndef Sudden_Underflow
  2759 	int denorm;
  2760 	ULong x;
  2761 #endif
  2762 	Bigint *b, *b1, *delta, *mlo, *mhi, *S;
  2763 	U d, d2, eps;
  2764 	double ds;
  2765 	char *s, *s0;
  2766 #ifdef Honor_FLT_ROUNDS
  2767 	int rounding;
  2768 #endif
  2769 #ifdef SET_INEXACT
  2770 	int inexact, oldinexact;
  2771 #endif
  2773 #ifndef MULTIPLE_THREADS
  2774 	if (dtoa_result) {
  2775 		freedtoa(dtoa_result);
  2776 		dtoa_result = 0;
  2778 #endif
  2780 	dval(d) = dd;
  2781 	if (word0(d) & Sign_bit) {
  2782 		/* set sign for everything, including 0's and NaNs */
  2783 		*sign = 1;
  2784 		word0(d) &= ~Sign_bit;	/* clear sign bit */
  2786 	else
  2787 		*sign = 0;
  2789 #if defined(IEEE_Arith) + defined(VAX)
  2790 #ifdef IEEE_Arith
  2791 	if ((word0(d) & Exp_mask) == Exp_mask)
  2792 #else
  2793 	if (word0(d)  == 0x8000)
  2794 #endif
  2796 		/* Infinity or NaN */
  2797 		*decpt = 9999;
  2798 #ifdef IEEE_Arith
  2799 		if (!word1(d) && !(word0(d) & 0xfffff))
  2800 			return nrv_alloc("Infinity", rve, 8);
  2801 #endif
  2802 		return nrv_alloc("NaN", rve, 3);
  2804 #endif
  2805 #ifdef IBM
  2806 	dval(d) += 0; /* normalize */
  2807 #endif
  2808 	if (!dval(d)) {
  2809 		*decpt = 1;
  2810 		return nrv_alloc("0", rve, 1);
  2813 #ifdef SET_INEXACT
  2814 	try_quick = oldinexact = get_inexact();
  2815 	inexact = 1;
  2816 #endif
  2817 #ifdef Honor_FLT_ROUNDS
  2818 	if ((rounding = Flt_Rounds) >= 2) {
  2819 		if (*sign)
  2820 			rounding = rounding == 2 ? 0 : 2;
  2821 		else
  2822 			if (rounding != 2)
  2823 				rounding = 0;
  2825 #endif
  2827 	b = d2b(dval(d), &be, &bbits);
  2828 #ifdef Sudden_Underflow
  2829 	i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1));
  2830 #else
  2831 	if (i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1))) {
  2832 #endif
  2833 		dval(d2) = dval(d);
  2834 		word0(d2) &= Frac_mask1;
  2835 		word0(d2) |= Exp_11;
  2836 #ifdef IBM
  2837 		if (j = 11 - hi0bits(word0(d2) & Frac_mask))
  2838 			dval(d2) /= 1 << j;
  2839 #endif
  2841 		/* log(x)	~=~ log(1.5) + (x-1.5)/1.5
  2842 		 * log10(x)	 =  log(x) / log(10)
  2843 		 *		~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
  2844 		 * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
  2846 		 * This suggests computing an approximation k to log10(d) by
  2848 		 * k = (i - Bias)*0.301029995663981
  2849 		 *	+ ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );
  2851 		 * We want k to be too large rather than too small.
  2852 		 * The error in the first-order Taylor series approximation
  2853 		 * is in our favor, so we just round up the constant enough
  2854 		 * to compensate for any error in the multiplication of
  2855 		 * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077,
  2856 		 * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14,
  2857 		 * adding 1e-13 to the constant term more than suffices.
  2858 		 * Hence we adjust the constant term to 0.1760912590558.
  2859 		 * (We could get a more accurate k by invoking log10,
  2860 		 *  but this is probably not worthwhile.)
  2861 		 */
  2863 		i -= Bias;
  2864 #ifdef IBM
  2865 		i <<= 2;
  2866 		i += j;
  2867 #endif
  2868 #ifndef Sudden_Underflow
  2869 		denorm = 0;
  2871 	else {
  2872 		/* d is denormalized */
  2874 		i = bbits + be + (Bias + (P-1) - 1);
  2875 		x = i > 32  ? word0(d) << 64 - i | word1(d) >> i - 32
  2876 			    : word1(d) << 32 - i;
  2877 		dval(d2) = x;
  2878 		word0(d2) -= 31*Exp_msk1; /* adjust exponent */
  2879 		i -= (Bias + (P-1) - 1) + 1;
  2880 		denorm = 1;
  2882 #endif
  2883 	ds = (dval(d2)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
  2884 	k = (int)ds;
  2885 	if (ds < 0. && ds != k)
  2886 		k--;	/* want k = floor(ds) */
  2887 	k_check = 1;
  2888 	if (k >= 0 && k <= Ten_pmax) {
  2889 		if (dval(d) < tens[k])
  2890 			k--;
  2891 		k_check = 0;
  2893 	j = bbits - i - 1;
  2894 	if (j >= 0) {
  2895 		b2 = 0;
  2896 		s2 = j;
  2898 	else {
  2899 		b2 = -j;
  2900 		s2 = 0;
  2902 	if (k >= 0) {
  2903 		b5 = 0;
  2904 		s5 = k;
  2905 		s2 += k;
  2907 	else {
  2908 		b2 -= k;
  2909 		b5 = -k;
  2910 		s5 = 0;
  2912 	if (mode < 0 || mode > 9)
  2913 		mode = 0;
  2915 #ifndef SET_INEXACT
  2916 #ifdef Check_FLT_ROUNDS
  2917 	try_quick = Rounding == 1;
  2918 #else
  2919 	try_quick = 1;
  2920 #endif
  2921 #endif /*SET_INEXACT*/
  2923 	if (mode > 5) {
  2924 		mode -= 4;
  2925 		try_quick = 0;
  2927 	leftright = 1;
  2928 	switch(mode) {
  2929 		case 0:
  2930 		case 1:
  2931 			ilim = ilim1 = -1;
  2932 			i = 18;
  2933 			ndigits = 0;
  2934 			break;
  2935 		case 2:
  2936 			leftright = 0;
  2937 			/* no break */
  2938 		case 4:
  2939 			if (ndigits <= 0)
  2940 				ndigits = 1;
  2941 			ilim = ilim1 = i = ndigits;
  2942 			break;
  2943 		case 3:
  2944 			leftright = 0;
  2945 			/* no break */
  2946 		case 5:
  2947 			i = ndigits + k + 1;
  2948 			ilim = i;
  2949 			ilim1 = i - 1;
  2950 			if (i <= 0)
  2951 				i = 1;
  2953 	s = s0 = rv_alloc(i);
  2955 #ifdef Honor_FLT_ROUNDS
  2956 	if (mode > 1 && rounding != 1)
  2957 		leftright = 0;
  2958 #endif
  2960 	if (ilim >= 0 && ilim <= Quick_max && try_quick) {
  2962 		/* Try to get by with floating-point arithmetic. */
  2964 		i = 0;
  2965 		dval(d2) = dval(d);
  2966 		k0 = k;
  2967 		ilim0 = ilim;
  2968 		ieps = 2; /* conservative */
  2969 		if (k > 0) {
  2970 			ds = tens[k&0xf];
  2971 			j = k >> 4;
  2972 			if (j & Bletch) {
  2973 				/* prevent overflows */
  2974 				j &= Bletch - 1;
  2975 				dval(d) /= bigtens[n_bigtens-1];
  2976 				ieps++;
  2978 			for(; j; j >>= 1, i++)
  2979 				if (j & 1) {
  2980 					ieps++;
  2981 					ds *= bigtens[i];
  2983 			dval(d) /= ds;
  2985 		else if (j1 = -k) {
  2986 			dval(d) *= tens[j1 & 0xf];
  2987 			for(j = j1 >> 4; j; j >>= 1, i++)
  2988 				if (j & 1) {
  2989 					ieps++;
  2990 					dval(d) *= bigtens[i];
  2993 		if (k_check && dval(d) < 1. && ilim > 0) {
  2994 			if (ilim1 <= 0)
  2995 				goto fast_failed;
  2996 			ilim = ilim1;
  2997 			k--;
  2998 			dval(d) *= 10.;
  2999 			ieps++;
  3001 		dval(eps) = ieps*dval(d) + 7.;
  3002 		word0(eps) -= (P-1)*Exp_msk1;
  3003 		if (ilim == 0) {
  3004 			S = mhi = 0;
  3005 			dval(d) -= 5.;
  3006 			if (dval(d) > dval(eps))
  3007 				goto one_digit;
  3008 			if (dval(d) < -dval(eps))
  3009 				goto no_digits;
  3010 			goto fast_failed;
  3012 #ifndef No_leftright
  3013 		if (leftright) {
  3014 			/* Use Steele & White method of only
  3015 			 * generating digits needed.
  3016 			 */
  3017 			dval(eps) = 0.5/tens[ilim-1] - dval(eps);
  3018 			for(i = 0;;) {
  3019 				L = dval(d);
  3020 				dval(d) -= L;
  3021 				*s++ = '0' + (int)L;
  3022 				if (dval(d) < dval(eps))
  3023 					goto ret1;
  3024 				if (1. - dval(d) < dval(eps))
  3025 					goto bump_up;
  3026 				if (++i >= ilim)
  3027 					break;
  3028 				dval(eps) *= 10.;
  3029 				dval(d) *= 10.;
  3032 		else {
  3033 #endif
  3034 			/* Generate ilim digits, then fix them up. */
  3035 			dval(eps) *= tens[ilim-1];
  3036 			for(i = 1;; i++, dval(d) *= 10.) {
  3037 				L = (Long)(dval(d));
  3038 				if (!(dval(d) -= L))
  3039 					ilim = i;
  3040 				*s++ = '0' + (int)L;
  3041 				if (i == ilim) {
  3042 					if (dval(d) > 0.5 + dval(eps))
  3043 						goto bump_up;
  3044 					else if (dval(d) < 0.5 - dval(eps)) {
  3045 						while(*--s == '0');
  3046 						s++;
  3047 						goto ret1;
  3049 					break;
  3052 #ifndef No_leftright
  3054 #endif
  3055  fast_failed:
  3056 		s = s0;
  3057 		dval(d) = dval(d2);
  3058 		k = k0;
  3059 		ilim = ilim0;
  3062 	/* Do we have a "small" integer? */
  3064 	if (be >= 0 && k <= Int_max) {
  3065 		/* Yes. */
  3066 		ds = tens[k];
  3067 		if (ndigits < 0 && ilim <= 0) {
  3068 			S = mhi = 0;
  3069 			if (ilim < 0 || dval(d) <= 5*ds)
  3070 				goto no_digits;
  3071 			goto one_digit;
  3073 		for(i = 1; i <= k+1; i++, dval(d) *= 10.) {
  3074 			L = (Long)(dval(d) / ds);
  3075 			dval(d) -= L*ds;
  3076 #ifdef Check_FLT_ROUNDS
  3077 			/* If FLT_ROUNDS == 2, L will usually be high by 1 */
  3078 			if (dval(d) < 0) {
  3079 				L--;
  3080 				dval(d) += ds;
  3082 #endif
  3083 			*s++ = '0' + (int)L;
  3084 			if (!dval(d)) {
  3085 #ifdef SET_INEXACT
  3086 				inexact = 0;
  3087 #endif
  3088 				break;
  3090 			if (i == ilim) {
  3091 #ifdef Honor_FLT_ROUNDS
  3092 				if (mode > 1)
  3093 				switch(rounding) {
  3094 				  case 0: goto ret1;
  3095 				  case 2: goto bump_up;
  3097 #endif
  3098 				dval(d) += dval(d);
  3099 				if (dval(d) > ds || dval(d) == ds && L & 1) {
  3100  bump_up:
  3101 					while(*--s == '9')
  3102 						if (s == s0) {
  3103 							k++;
  3104 							*s = '0';
  3105 							break;
  3107 					++*s++;
  3109 				break;
  3112 		goto ret1;
  3115 	m2 = b2;
  3116 	m5 = b5;
  3117 	mhi = mlo = 0;
  3118 	if (leftright) {
  3119 		i =
  3120 #ifndef Sudden_Underflow
  3121 			denorm ? be + (Bias + (P-1) - 1 + 1) :
  3122 #endif
  3123 #ifdef IBM
  3124 			1 + 4*P - 3 - bbits + ((bbits + be - 1) & 3);
  3125 #else
  3126 			1 + P - bbits;
  3127 #endif
  3128 		b2 += i;
  3129 		s2 += i;
  3130 		mhi = i2b(1);
  3132 	if (m2 > 0 && s2 > 0) {
  3133 		i = m2 < s2 ? m2 : s2;
  3134 		b2 -= i;
  3135 		m2 -= i;
  3136 		s2 -= i;
  3138 	if (b5 > 0) {
  3139 		if (leftright) {
  3140 			if (m5 > 0) {
  3141 				mhi = pow5mult(mhi, m5);
  3142 				b1 = mult(mhi, b);
  3143 				Bfree(b);
  3144 				b = b1;
  3146 			if (j = b5 - m5)
  3147 				b = pow5mult(b, j);
  3149 		else
  3150 			b = pow5mult(b, b5);
  3152 	S = i2b(1);
  3153 	if (s5 > 0)
  3154 		S = pow5mult(S, s5);
  3156 	/* Check for special case that d is a normalized power of 2. */
  3158 	spec_case = 0;
  3159 	if ((mode < 2 || leftright)
  3160 #ifdef Honor_FLT_ROUNDS
  3161 			&& rounding == 1
  3162 #endif
  3163 				) {
  3164 		if (!word1(d) && !(word0(d) & Bndry_mask)
  3165 #ifndef Sudden_Underflow
  3166 		 && word0(d) & (Exp_mask & ~Exp_msk1)
  3167 #endif
  3168 				) {
  3169 			/* The special case */
  3170 			b2 += Log2P;
  3171 			s2 += Log2P;
  3172 			spec_case = 1;
  3176 	/* Arrange for convenient computation of quotients:
  3177 	 * shift left if necessary so divisor has 4 leading 0 bits.
  3179 	 * Perhaps we should just compute leading 28 bits of S once
  3180 	 * and for all and pass them and a shift to quorem, so it
  3181 	 * can do shifts and ors to compute the numerator for q.
  3182 	 */
  3183 #ifdef Pack_32
  3184 	if (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f)
  3185 		i = 32 - i;
  3186 #else
  3187 	if (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0xf)
  3188 		i = 16 - i;
  3189 #endif
  3190 	if (i > 4) {
  3191 		i -= 4;
  3192 		b2 += i;
  3193 		m2 += i;
  3194 		s2 += i;
  3196 	else if (i < 4) {
  3197 		i += 28;
  3198 		b2 += i;
  3199 		m2 += i;
  3200 		s2 += i;
  3202 	if (b2 > 0)
  3203 		b = lshift(b, b2);
  3204 	if (s2 > 0)
  3205 		S = lshift(S, s2);
  3206 	if (k_check) {
  3207 		if (cmp(b,S) < 0) {
  3208 			k--;
  3209 			b = multadd(b, 10, 0);	/* we botched the k estimate */
  3210 			if (leftright)
  3211 				mhi = multadd(mhi, 10, 0);
  3212 			ilim = ilim1;
  3215 	if (ilim <= 0 && (mode == 3 || mode == 5)) {
  3216 		if (ilim < 0 || cmp(b,S = multadd(S,5,0)) <= 0) {
  3217 			/* no digits, fcvt style */
  3218  no_digits:
  3219 			k = -1 - ndigits;
  3220 			goto ret;
  3222  one_digit:
  3223 		*s++ = '1';
  3224 		k++;
  3225 		goto ret;
  3227 	if (leftright) {
  3228 		if (m2 > 0)
  3229 			mhi = lshift(mhi, m2);
  3231 		/* Compute mlo -- check for special case
  3232 		 * that d is a normalized power of 2.
  3233 		 */
  3235 		mlo = mhi;
  3236 		if (spec_case) {
  3237 			mhi = Balloc(mhi->k);
  3238 			Bcopy(mhi, mlo);
  3239 			mhi = lshift(mhi, Log2P);
  3242 		for(i = 1;;i++) {
  3243 			dig = quorem(b,S) + '0';
  3244 			/* Do we yet have the shortest decimal string
  3245 			 * that will round to d?
  3246 			 */
  3247 			j = cmp(b, mlo);
  3248 			delta = diff(S, mhi);
  3249 			j1 = delta->sign ? 1 : cmp(b, delta);
  3250 			Bfree(delta);
  3251 #ifndef ROUND_BIASED
  3252 			if (j1 == 0 && mode != 1 && !(word1(d) & 1)
  3253 #ifdef Honor_FLT_ROUNDS
  3254 				&& rounding >= 1
  3255 #endif
  3256 								   ) {
  3257 				if (dig == '9')
  3258 					goto round_9_up;
  3259 				if (j > 0)
  3260 					dig++;
  3261 #ifdef SET_INEXACT
  3262 				else if (!b->x[0] && b->wds <= 1)
  3263 					inexact = 0;
  3264 #endif
  3265 				*s++ = dig;
  3266 				goto ret;
  3268 #endif
  3269 			if (j < 0 || j == 0 && mode != 1
  3270 #ifndef ROUND_BIASED
  3271 							&& !(word1(d) & 1)
  3272 #endif
  3273 					) {
  3274 				if (!b->x[0] && b->wds <= 1) {
  3275 #ifdef SET_INEXACT
  3276 					inexact = 0;
  3277 #endif
  3278 					goto accept_dig;
  3280 #ifdef Honor_FLT_ROUNDS
  3281 				if (mode > 1)
  3282 				 switch(rounding) {
  3283 				  case 0: goto accept_dig;
  3284 				  case 2: goto keep_dig;
  3286 #endif /*Honor_FLT_ROUNDS*/
  3287 				if (j1 > 0) {
  3288 					b = lshift(b, 1);
  3289 					j1 = cmp(b, S);
  3290 					if ((j1 > 0 || j1 == 0 && dig & 1)
  3291 					&& dig++ == '9')
  3292 						goto round_9_up;
  3294  accept_dig:
  3295 				*s++ = dig;
  3296 				goto ret;
  3298 			if (j1 > 0) {
  3299 #ifdef Honor_FLT_ROUNDS
  3300 				if (!rounding)
  3301 					goto accept_dig;
  3302 #endif
  3303 				if (dig == '9') { /* possible if i == 1 */
  3304  round_9_up:
  3305 					*s++ = '9';
  3306 					goto roundoff;
  3308 				*s++ = dig + 1;
  3309 				goto ret;
  3311 #ifdef Honor_FLT_ROUNDS
  3312  keep_dig:
  3313 #endif
  3314 			*s++ = dig;
  3315 			if (i == ilim)
  3316 				break;
  3317 			b = multadd(b, 10, 0);
  3318 			if (mlo == mhi)
  3319 				mlo = mhi = multadd(mhi, 10, 0);
  3320 			else {
  3321 				mlo = multadd(mlo, 10, 0);
  3322 				mhi = multadd(mhi, 10, 0);
  3326 	else
  3327 		for(i = 1;; i++) {
  3328 			*s++ = dig = quorem(b,S) + '0';
  3329 			if (!b->x[0] && b->wds <= 1) {
  3330 #ifdef SET_INEXACT
  3331 				inexact = 0;
  3332 #endif
  3333 				goto ret;
  3335 			if (i >= ilim)
  3336 				break;
  3337 			b = multadd(b, 10, 0);
  3340 	/* Round off last digit */
  3342 #ifdef Honor_FLT_ROUNDS
  3343 	switch(rounding) {
  3344 	  case 0: goto trimzeros;
  3345 	  case 2: goto roundoff;
  3347 #endif
  3348 	b = lshift(b, 1);
  3349 	j = cmp(b, S);
  3350 	if (j > 0 || j == 0 && dig & 1) {
  3351  roundoff:
  3352 		while(*--s == '9')
  3353 			if (s == s0) {
  3354 				k++;
  3355 				*s++ = '1';
  3356 				goto ret;
  3358 		++*s++;
  3360 	else {
  3361 #ifdef Honor_FLT_ROUNDS
  3362  trimzeros:
  3363 #endif
  3364 		while(*--s == '0');
  3365 		s++;
  3367  ret:
  3368 	Bfree(S);
  3369 	if (mhi) {
  3370 		if (mlo && mlo != mhi)
  3371 			Bfree(mlo);
  3372 		Bfree(mhi);
  3374  ret1:
  3375 #ifdef SET_INEXACT
  3376 	if (inexact) {
  3377 		if (!oldinexact) {
  3378 			word0(d) = Exp_1 + (70 << Exp_shift);
  3379 			word1(d) = 0;
  3380 			dval(d) += 1.;
  3383 	else if (!oldinexact)
  3384 		clear_inexact();
  3385 #endif
  3386 	Bfree(b);
  3387 	*s = 0;
  3388 	*decpt = k + 1;
  3389 	if (rve)
  3390 		*rve = s;
  3391 	return s0;
  3393 #ifdef __cplusplus
  3395 #endif
  3397 PR_IMPLEMENT(PRStatus)
  3398 PR_dtoa(PRFloat64 d, PRIntn mode, PRIntn ndigits,
  3399 	PRIntn *decpt, PRIntn *sign, char **rve, char *buf, PRSize bufsize)
  3401     char *result;
  3402     PRSize resultlen;
  3403     PRStatus rv = PR_FAILURE;
  3405     if (!_pr_initialized) _PR_ImplicitInitialization();
  3407     if (mode < 0 || mode > 3) {
  3408         PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
  3409         return rv;
  3411     result = dtoa(d, mode, ndigits, decpt, sign, rve);
  3412     if (!result) {
  3413         PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
  3414         return rv;
  3416     resultlen = strlen(result)+1;
  3417     if (bufsize < resultlen) {
  3418         PR_SetError(PR_BUFFER_OVERFLOW_ERROR, 0);
  3419     } else {
  3420         memcpy(buf, result, resultlen);
  3421         if (rve) {
  3422             *rve = buf + (*rve - result);
  3424         rv = PR_SUCCESS;
  3426     freedtoa(result);
  3427     return rv;  
  3430 /*
  3431 ** conversion routines for floating point
  3432 ** prcsn - number of digits of precision to generate floating
  3433 ** point value.
  3434 ** This should be reparameterized so that you can send in a
  3435 **   prcn for the positive and negative ranges.  For now, 
  3436 **   conform to the ECMA JavaScript spec which says numbers
  3437 **   less than 1e-6 are in scientific notation.
  3438 ** Also, the ECMA spec says that there should always be a
  3439 **   '+' or '-' after the 'e' in scientific notation
  3440 */
  3441 PR_IMPLEMENT(void)
  3442 PR_cnvtf(char *buf, int bufsz, int prcsn, double dfval)
  3444     PRIntn decpt, sign, numdigits;
  3445     char *num, *nump;
  3446     char *bufp = buf;
  3447     char *endnum;
  3448     U fval;
  3450     dval(fval) = dfval;
  3451     /* If anything fails, we store an empty string in 'buf' */
  3452     num = (char*)PR_MALLOC(bufsz);
  3453     if (num == NULL) {
  3454         buf[0] = '\0';
  3455         return;
  3457     /* XXX Why use mode 1? */
  3458     if (PR_dtoa(dval(fval),1,prcsn,&decpt,&sign,&endnum,num,bufsz)
  3459             == PR_FAILURE) {
  3460         buf[0] = '\0';
  3461         goto done;
  3463     numdigits = endnum - num;
  3464     nump = num;
  3466     if (sign &&
  3467         !(word0(fval) == Sign_bit && word1(fval) == 0) &&
  3468         !((word0(fval) & Exp_mask) == Exp_mask &&
  3469           (word1(fval) || (word0(fval) & 0xfffff)))) {
  3470         *bufp++ = '-';
  3473     if (decpt == 9999) {
  3474         while ((*bufp++ = *nump++) != 0) {} /* nothing to execute */
  3475         goto done;
  3478     if (decpt > (prcsn+1) || decpt < -(prcsn-1) || decpt < -5) {
  3479         *bufp++ = *nump++;
  3480         if (numdigits != 1) {
  3481             *bufp++ = '.';
  3484         while (*nump != '\0') {
  3485             *bufp++ = *nump++;
  3487         *bufp++ = 'e';
  3488         PR_snprintf(bufp, bufsz - (bufp - buf), "%+d", decpt-1);
  3489     } else if (decpt >= 0) {
  3490         if (decpt == 0) {
  3491             *bufp++ = '0';
  3492         } else {
  3493             while (decpt--) {
  3494                 if (*nump != '\0') {
  3495                     *bufp++ = *nump++;
  3496                 } else {
  3497                     *bufp++ = '0';
  3501         if (*nump != '\0') {
  3502             *bufp++ = '.';
  3503             while (*nump != '\0') {
  3504                 *bufp++ = *nump++;
  3507         *bufp++ = '\0';
  3508     } else if (decpt < 0) {
  3509         *bufp++ = '0';
  3510         *bufp++ = '.';
  3511         while (decpt++) {
  3512             *bufp++ = '0';
  3515         while (*nump != '\0') {
  3516             *bufp++ = *nump++;
  3518         *bufp++ = '\0';
  3520 done:
  3521     PR_DELETE(num);

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