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-/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
- *
- * ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Communicator client code, released
- * March 31, 1998.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of the GNU General Public License Version 2 or later (the "GPL"),
- * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
-/*
- * Portable double to alphanumeric string and back converters.
- */
-#include "jsstddef.h"
-#include "jslibmath.h"
-#include "jstypes.h"
-#include "jsdtoa.h"
-#include "jsprf.h"
-#include "jsutil.h" /* Added by JSIFY */
-#include "jspubtd.h"
-#include "jsnum.h"
-
-#ifdef JS_THREADSAFE
-#include "prlock.h"
-#endif
-
-/****************************************************************
- *
- * The author of this software is David M. Gay.
- *
- * Copyright (c) 1991 by Lucent Technologies.
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose without fee is hereby granted, provided that this entire notice
- * is included in all copies of any software which is or includes a copy
- * or modification of this software and in all copies of the supporting
- * documentation for such software.
- *
- * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY
- * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
- * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
- *
- ***************************************************************/
-
-/* Please send bug reports to
- David M. Gay
- Bell Laboratories, Room 2C-463
- 600 Mountain Avenue
- Murray Hill, NJ 07974-0636
- U.S.A.
- dmg@bell-labs.com
- */
-
-/* On a machine with IEEE extended-precision registers, it is
- * necessary to specify double-precision (53-bit) rounding precision
- * before invoking strtod or dtoa. If the machine uses (the equivalent
- * of) Intel 80x87 arithmetic, the call
- * _control87(PC_53, MCW_PC);
- * does this with many compilers. Whether this or another call is
- * appropriate depends on the compiler; for this to work, it may be
- * necessary to #include "float.h" or another system-dependent header
- * file.
- */
-
-/* strtod for IEEE-arithmetic machines.
- *
- * This strtod returns a nearest machine number to the input decimal
- * string (or sets err to JS_DTOA_ERANGE or JS_DTOA_ENOMEM). With IEEE
- * arithmetic, ties are broken by the IEEE round-even rule. Otherwise
- * ties are broken by biased rounding (add half and chop).
- *
- * Inspired loosely by William D. Clinger's paper "How to Read Floating
- * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 92-101].
- *
- * Modifications:
- *
- * 1. We only require IEEE double-precision
- * arithmetic (not IEEE double-extended).
- * 2. We get by with floating-point arithmetic in a case that
- * Clinger missed -- when we're computing d * 10^n
- * for a small integer d and the integer n is not too
- * much larger than 22 (the maximum integer k for which
- * we can represent 10^k exactly), we may be able to
- * compute (d*10^k) * 10^(e-k) with just one roundoff.
- * 3. Rather than a bit-at-a-time adjustment of the binary
- * result in the hard case, we use floating-point
- * arithmetic to determine the adjustment to within
- * one bit; only in really hard cases do we need to
- * compute a second residual.
- * 4. Because of 3., we don't need a large table of powers of 10
- * for ten-to-e (just some small tables, e.g. of 10^k
- * for 0 <= k <= 22).
- */
-
-/*
- * #define IEEE_8087 for IEEE-arithmetic machines where the least
- * significant byte has the lowest address.
- * #define IEEE_MC68k for IEEE-arithmetic machines where the most
- * significant byte has the lowest address.
- * #define Long int on machines with 32-bit ints and 64-bit longs.
- * #define Sudden_Underflow for IEEE-format machines without gradual
- * underflow (i.e., that flush to zero on underflow).
- * #define No_leftright to omit left-right logic in fast floating-point
- * computation of js_dtoa.
- * #define Check_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3.
- * #define RND_PRODQUOT to use rnd_prod and rnd_quot (assembly routines
- * that use extended-precision instructions to compute rounded
- * products and quotients) with IBM.
- * #define ROUND_BIASED for IEEE-format with biased rounding.
- * #define Inaccurate_Divide for IEEE-format with correctly rounded
- * products but inaccurate quotients, e.g., for Intel i860.
- * #define JS_HAVE_LONG_LONG on machines that have a "long long"
- * integer type (of >= 64 bits). If long long is available and the name is
- * something other than "long long", #define Llong to be the name,
- * and if "unsigned Llong" does not work as an unsigned version of
- * Llong, #define #ULLong to be the corresponding unsigned type.
- * #define Bad_float_h if your system lacks a float.h or if it does not
- * define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP,
- * FLT_RADIX, FLT_ROUNDS, and DBL_MAX.
- * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n)
- * if memory is available and otherwise does something you deem
- * appropriate. If MALLOC is undefined, malloc will be invoked
- * directly -- and assumed always to succeed.
- * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
- * memory allocations from a private pool of memory when possible.
- * When used, the private pool is PRIVATE_MEM bytes long: 2000 bytes,
- * unless #defined to be a different length. This default length
- * suffices to get rid of MALLOC calls except for unusual cases,
- * such as decimal-to-binary conversion of a very long string of
- * digits.
- * #define INFNAN_CHECK on IEEE systems to cause strtod to check for
- * Infinity and NaN (case insensitively). On some systems (e.g.,
- * some HP systems), it may be necessary to #define NAN_WORD0
- * appropriately -- to the most significant word of a quiet NaN.
- * (On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.)
- * #define MULTIPLE_THREADS if the system offers preemptively scheduled
- * multiple threads. In this case, you must provide (or suitably
- * #define) two locks, acquired by ACQUIRE_DTOA_LOCK() and released
- * by RELEASE_DTOA_LOCK(). (The second lock, accessed
- * in pow5mult, ensures lazy evaluation of only one copy of high
- * powers of 5; omitting this lock would introduce a small
- * probability of wasting memory, but would otherwise be harmless.)
- * You must also invoke freedtoa(s) to free the value s returned by
- * dtoa. You may do so whether or not MULTIPLE_THREADS is #defined.
- * #define NO_IEEE_Scale to disable new (Feb. 1997) logic in strtod that
- * avoids underflows on inputs whose result does not underflow.
- */
-#ifdef IS_LITTLE_ENDIAN
-#define IEEE_8087
-#else
-#define IEEE_MC68k
-#endif
-
-#ifndef Long
-#define Long int32
-#endif
-
-#ifndef ULong
-#define ULong uint32
-#endif
-
-#define Bug(errorMessageString) JS_ASSERT(!errorMessageString)
-
-#include "stdlib.h"
-#include "string.h"
-
-#ifdef MALLOC
-extern void *MALLOC(size_t);
-#else
-#define MALLOC malloc
-#endif
-
-#define Omit_Private_Memory
-/* Private memory currently doesn't work with JS_THREADSAFE */
-#ifndef Omit_Private_Memory
-#ifndef PRIVATE_MEM
-#define PRIVATE_MEM 2000
-#endif
-#define PRIVATE_mem ((PRIVATE_MEM+sizeof(double)-1)/sizeof(double))
-static double private_mem[PRIVATE_mem], *pmem_next = private_mem;
-#endif
-
-#ifdef Bad_float_h
-#undef __STDC__
-
-#define DBL_DIG 15
-#define DBL_MAX_10_EXP 308
-#define DBL_MAX_EXP 1024
-#define FLT_RADIX 2
-#define FLT_ROUNDS 1
-#define DBL_MAX 1.7976931348623157e+308
-
-
-
-#ifndef LONG_MAX
-#define LONG_MAX 2147483647
-#endif
-
-#else /* ifndef Bad_float_h */
-#include "float.h"
-/*
- * MacOS 10.2 defines the macro FLT_ROUNDS to an internal function
- * which does not exist on 10.1. We can safely #define it to 1 here
- * to allow 10.2 builds to run on 10.1, since we can't use fesetround()
- * (which does not exist on 10.1 either).
- */
-#if defined(MACOS_DEPLOYMENT_TARGET) && (MACOS_DEPLOYMENT_TARGET < 100200)
-#undef FLT_ROUNDS
-#define FLT_ROUNDS 1
-#endif
-#endif /* Bad_float_h */
-
-#ifndef __MATH_H__
-#include "math.h"
-#endif
-
-#ifndef CONST
-#define CONST const
-#endif
-
-#if defined(IEEE_8087) + defined(IEEE_MC68k) != 1
-Exactly one of IEEE_8087 or IEEE_MC68k should be defined.
-#endif
-
-#define word0(x) JSDOUBLE_HI32(x)
-#define set_word0(x, y) JSDOUBLE_SET_HI32(x, y)
-#define word1(x) JSDOUBLE_LO32(x)
-#define set_word1(x, y) JSDOUBLE_SET_LO32(x, y)
-
-#define Storeinc(a,b,c) (*(a)++ = (b) << 16 | (c) & 0xffff)
-
-/* #define P DBL_MANT_DIG */
-/* Ten_pmax = floor(P*log(2)/log(5)) */
-/* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
-/* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
-/* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
-
-#define Exp_shift 20
-#define Exp_shift1 20
-#define Exp_msk1 0x100000
-#define Exp_msk11 0x100000
-#define Exp_mask 0x7ff00000
-#define P 53
-#define Bias 1023
-#define Emin (-1022)
-#define Exp_1 0x3ff00000
-#define Exp_11 0x3ff00000
-#define Ebits 11
-#define Frac_mask 0xfffff
-#define Frac_mask1 0xfffff
-#define Ten_pmax 22
-#define Bletch 0x10
-#define Bndry_mask 0xfffff
-#define Bndry_mask1 0xfffff
-#define LSB 1
-#define Sign_bit 0x80000000
-#define Log2P 1
-#define Tiny0 0
-#define Tiny1 1
-#define Quick_max 14
-#define Int_max 14
-#define Infinite(x) (word0(x) == 0x7ff00000) /* sufficient test for here */
-#ifndef NO_IEEE_Scale
-#define Avoid_Underflow
-#endif
-
-
-
-#ifdef RND_PRODQUOT
-#define rounded_product(a,b) a = rnd_prod(a, b)
-#define rounded_quotient(a,b) a = rnd_quot(a, b)
-extern double rnd_prod(double, double), rnd_quot(double, double);
-#else
-#define rounded_product(a,b) a *= b
-#define rounded_quotient(a,b) a /= b
-#endif
-
-#define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
-#define Big1 0xffffffff
-
-#ifndef JS_HAVE_LONG_LONG
-#undef ULLong
-#else /* long long available */
-#ifndef Llong
-#define Llong JSInt64
-#endif
-#ifndef ULLong
-#define ULLong JSUint64
-#endif
-#endif /* JS_HAVE_LONG_LONG */
-
-#ifdef JS_THREADSAFE
-#define MULTIPLE_THREADS
-static PRLock *freelist_lock;
-#define ACQUIRE_DTOA_LOCK() \
- JS_BEGIN_MACRO \
- if (!initialized) \
- InitDtoa(); \
- PR_Lock(freelist_lock); \
- JS_END_MACRO
-#define RELEASE_DTOA_LOCK() PR_Unlock(freelist_lock)
-#else
-#undef MULTIPLE_THREADS
-#define ACQUIRE_DTOA_LOCK() /*nothing*/
-#define RELEASE_DTOA_LOCK() /*nothing*/
-#endif
-
-#define Kmax 15
-
-struct Bigint {
- struct Bigint *next; /* Free list link */
- int32 k; /* lg2(maxwds) */
- int32 maxwds; /* Number of words allocated for x */
- int32 sign; /* Zero if positive, 1 if negative. Ignored by most Bigint routines! */
- int32 wds; /* Actual number of words. If value is nonzero, the most significant word must be nonzero. */
- ULong x[1]; /* wds words of number in little endian order */
-};
-
-#ifdef ENABLE_OOM_TESTING
-/* Out-of-memory testing. Use a good testcase (over and over) and then use
- * these routines to cause a memory failure on every possible Balloc allocation,
- * to make sure that all out-of-memory paths can be followed. See bug 14044.
- */
-
-static int allocationNum; /* which allocation is next? */
-static int desiredFailure; /* which allocation should fail? */
-
-/**
- * js_BigintTestingReset
- *
- * Call at the beginning of a test run to set the allocation failure position.
- * (Set to 0 to just have the engine count allocations without failing.)
- */
-JS_PUBLIC_API(void)
-js_BigintTestingReset(int newFailure)
-{
- allocationNum = 0;
- desiredFailure = newFailure;
-}
-
-/**
- * js_BigintTestingWhere
- *
- * Report the current allocation position. This is really only useful when you
- * want to learn how many allocations a test run has.
- */
-JS_PUBLIC_API(int)
-js_BigintTestingWhere()
-{
- return allocationNum;
-}
-
-
-/*
- * So here's what you do: Set up a fantastic test case that exercises the
- * elements of the code you wish. Set the failure point at 0 and run the test,
- * then get the allocation position. This number is the number of allocations
- * your test makes. Now loop from 1 to that number, setting the failure point
- * at each loop count, and run the test over and over, causing failures at each
- * step. Any memory failure *should* cause a Out-Of-Memory exception; if it
- * doesn't, then there's still an error here.
- */
-#endif
-
-typedef struct Bigint Bigint;
-
-static Bigint *freelist[Kmax+1];
-
-/*
- * Allocate a Bigint with 2^k words.
- * This is not threadsafe. The caller must use thread locks
- */
-static Bigint *Balloc(int32 k)
-{
- int32 x;
- Bigint *rv;
-#ifndef Omit_Private_Memory
- uint32 len;
-#endif
-
-#ifdef ENABLE_OOM_TESTING
- if (++allocationNum == desiredFailure) {
- printf("Forced Failing Allocation number %d\n", allocationNum);
- return NULL;
- }
-#endif
-
- if ((rv = freelist[k]) != NULL)
- freelist[k] = rv->next;
- if (rv == NULL) {
- x = 1 << k;
-#ifdef Omit_Private_Memory
- rv = (Bigint *)MALLOC(sizeof(Bigint) + (x-1)*sizeof(ULong));
-#else
- len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1)
- /sizeof(double);
- if (pmem_next - private_mem + len <= PRIVATE_mem) {
- rv = (Bigint*)pmem_next;
- pmem_next += len;
- }
- else
- rv = (Bigint*)MALLOC(len*sizeof(double));
-#endif
- if (!rv)
- return NULL;
- rv->k = k;
- rv->maxwds = x;
- }
- rv->sign = rv->wds = 0;
- return rv;
-}
-
-static void Bfree(Bigint *v)
-{
- if (v) {
- v->next = freelist[v->k];
- freelist[v->k] = v;
- }
-}
-
-#define Bcopy(x,y) memcpy((char *)&x->sign, (char *)&y->sign, \
- y->wds*sizeof(Long) + 2*sizeof(int32))
-
-/* Return b*m + a. Deallocate the old b. Both a and m must be between 0 and
- * 65535 inclusive. NOTE: old b is deallocated on memory failure.
- */
-static Bigint *multadd(Bigint *b, int32 m, int32 a)
-{
- int32 i, wds;
-#ifdef ULLong
- ULong *x;
- ULLong carry, y;
-#else
- ULong carry, *x, y;
- ULong xi, z;
-#endif
- Bigint *b1;
-
-#ifdef ENABLE_OOM_TESTING
- if (++allocationNum == desiredFailure) {
- /* Faux allocation, because I'm not getting all of the failure paths
- * without it.
- */
- printf("Forced Failing Allocation number %d\n", allocationNum);
- Bfree(b);
- return NULL;
- }
-#endif
-
- wds = b->wds;
- x = b->x;
- i = 0;
- carry = a;
- do {
-#ifdef ULLong
- y = *x * (ULLong)m + carry;
- carry = y >> 32;
- *x++ = (ULong)(y & 0xffffffffUL);
-#else
- xi = *x;
- y = (xi & 0xffff) * m + carry;
- z = (xi >> 16) * m + (y >> 16);
- carry = z >> 16;
- *x++ = (z << 16) + (y & 0xffff);
-#endif
- }
- while(++i < wds);
- if (carry) {
- if (wds >= b->maxwds) {
- b1 = Balloc(b->k+1);
- if (!b1) {
- Bfree(b);
- return NULL;
- }
- Bcopy(b1, b);
- Bfree(b);
- b = b1;
- }
- b->x[wds++] = (ULong)carry;
- b->wds = wds;
- }
- return b;
-}
-
-static Bigint *s2b(CONST char *s, int32 nd0, int32 nd, ULong y9)
-{
- Bigint *b;
- int32 i, k;
- Long x, y;
-
- x = (nd + 8) / 9;
- for(k = 0, y = 1; x > y; y <<= 1, k++) ;
- b = Balloc(k);
- if (!b)
- return NULL;
- b->x[0] = y9;
- b->wds = 1;
-
- i = 9;
- if (9 < nd0) {
- s += 9;
- do {
- b = multadd(b, 10, *s++ - '0');
- if (!b)
- return NULL;
- } while(++i < nd0);
- s++;
- }
- else
- s += 10;
- for(; i < nd; i++) {
- b = multadd(b, 10, *s++ - '0');
- if (!b)
- return NULL;
- }
- return b;
-}
-
-
-/* Return the number (0 through 32) of most significant zero bits in x. */
-static int32 hi0bits(register ULong x)
-{
- register int32 k = 0;
-
- if (!(x & 0xffff0000)) {
- k = 16;
- x <<= 16;
- }
- if (!(x & 0xff000000)) {
- k += 8;
- x <<= 8;
- }
- if (!(x & 0xf0000000)) {
- k += 4;
- x <<= 4;
- }
- if (!(x & 0xc0000000)) {
- k += 2;
- x <<= 2;
- }
- if (!(x & 0x80000000)) {
- k++;
- if (!(x & 0x40000000))
- return 32;
- }
- return k;
-}
-
-
-/* Return the number (0 through 32) of least significant zero bits in y.
- * Also shift y to the right past these 0 through 32 zeros so that y's
- * least significant bit will be set unless y was originally zero. */
-static int32 lo0bits(ULong *y)
-{
- register int32 k;
- register ULong x = *y;
-
- if (x & 7) {
- if (x & 1)
- return 0;
- if (x & 2) {
- *y = x >> 1;
- return 1;
- }
- *y = x >> 2;
- return 2;
- }
- k = 0;
- if (!(x & 0xffff)) {
- k = 16;
- x >>= 16;
- }
- if (!(x & 0xff)) {
- k += 8;
- x >>= 8;
- }
- if (!(x & 0xf)) {
- k += 4;
- x >>= 4;
- }
- if (!(x & 0x3)) {
- k += 2;
- x >>= 2;
- }
- if (!(x & 1)) {
- k++;
- x >>= 1;
- if (!x & 1)
- return 32;
- }
- *y = x;
- return k;
-}
-
-/* Return a new Bigint with the given integer value, which must be nonnegative. */
-static Bigint *i2b(int32 i)
-{
- Bigint *b;
-
- b = Balloc(1);
- if (!b)
- return NULL;
- b->x[0] = i;
- b->wds = 1;
- return b;
-}
-
-/* Return a newly allocated product of a and b. */
-static Bigint *mult(CONST Bigint *a, CONST Bigint *b)
-{
- CONST Bigint *t;
- Bigint *c;
- int32 k, wa, wb, wc;
- ULong y;
- ULong *xc, *xc0, *xce;
- CONST ULong *x, *xa, *xae, *xb, *xbe;
-#ifdef ULLong
- ULLong carry, z;
-#else
- ULong carry, z;
- ULong z2;
-#endif
-
- if (a->wds < b->wds) {
- t = a;
- a = b;
- b = t;
- }
- k = a->k;
- wa = a->wds;
- wb = b->wds;
- wc = wa + wb;
- if (wc > a->maxwds)
- k++;
- c = Balloc(k);
- if (!c)
- return NULL;
- for(xc = c->x, xce = xc + wc; xc < xce; xc++)
- *xc = 0;
- xa = a->x;
- xae = xa + wa;
- xb = b->x;
- xbe = xb + wb;
- xc0 = c->x;
-#ifdef ULLong
- for(; xb < xbe; xc0++) {
- if ((y = *xb++) != 0) {
- x = xa;
- xc = xc0;
- carry = 0;
- do {
- z = *x++ * (ULLong)y + *xc + carry;
- carry = z >> 32;
- *xc++ = (ULong)(z & 0xffffffffUL);
- }
- while(x < xae);
- *xc = (ULong)carry;
- }
- }
-#else
- for(; xb < xbe; xb++, xc0++) {
- if ((y = *xb & 0xffff) != 0) {
- x = xa;
- xc = xc0;
- carry = 0;
- do {
- z = (*x & 0xffff) * y + (*xc & 0xffff) + carry;
- carry = z >> 16;
- z2 = (*x++ >> 16) * y + (*xc >> 16) + carry;
- carry = z2 >> 16;
- Storeinc(xc, z2, z);
- }
- while(x < xae);
- *xc = carry;
- }
- if ((y = *xb >> 16) != 0) {
- x = xa;
- xc = xc0;
- carry = 0;
- z2 = *xc;
- do {
- z = (*x & 0xffff) * y + (*xc >> 16) + carry;
- carry = z >> 16;
- Storeinc(xc, z, z2);
- z2 = (*x++ >> 16) * y + (*xc & 0xffff) + carry;
- carry = z2 >> 16;
- }
- while(x < xae);
- *xc = z2;
- }
- }
-#endif
- for(xc0 = c->x, xc = xc0 + wc; wc > 0 && !*--xc; --wc) ;
- c->wds = wc;
- return c;
-}
-
-/*
- * 'p5s' points to a linked list of Bigints that are powers of 5.
- * This list grows on demand, and it can only grow: it won't change
- * in any other way. So if we read 'p5s' or the 'next' field of
- * some Bigint on the list, and it is not NULL, we know it won't
- * change to NULL or some other value. Only when the value of
- * 'p5s' or 'next' is NULL do we need to acquire the lock and add
- * a new Bigint to the list.
- */
-
-static Bigint *p5s;
-
-#ifdef JS_THREADSAFE
-static PRLock *p5s_lock;
-#endif
-
-/* Return b * 5^k. Deallocate the old b. k must be nonnegative. */
-/* NOTE: old b is deallocated on memory failure. */
-static Bigint *pow5mult(Bigint *b, int32 k)
-{
- Bigint *b1, *p5, *p51;
- int32 i;
- static CONST int32 p05[3] = { 5, 25, 125 };
-
- if ((i = k & 3) != 0) {
- b = multadd(b, p05[i-1], 0);
- if (!b)
- return NULL;
- }
-
- if (!(k >>= 2))
- return b;
- if (!(p5 = p5s)) {
-#ifdef JS_THREADSAFE
- /*
- * We take great care to not call i2b() and Bfree()
- * while holding the lock.
- */
- Bigint *wasted_effort = NULL;
- p5 = i2b(625);
- if (!p5) {
- Bfree(b);
- return NULL;
- }
- /* lock and check again */
- PR_Lock(p5s_lock);
- if (!p5s) {
- /* first time */
- p5s = p5;
- p5->next = 0;
- } else {
- /* some other thread just beat us */
- wasted_effort = p5;
- p5 = p5s;
- }
- PR_Unlock(p5s_lock);
- if (wasted_effort) {
- Bfree(wasted_effort);
- }
-#else
- /* first time */
- p5 = p5s = i2b(625);
- if (!p5) {
- Bfree(b);
- return NULL;
- }
- p5->next = 0;
-#endif
- }
- for(;;) {
- if (k & 1) {
- b1 = mult(b, p5);
- Bfree(b);
- if (!b1)
- return NULL;
- b = b1;
- }
- if (!(k >>= 1))
- break;
- if (!(p51 = p5->next)) {
-#ifdef JS_THREADSAFE
- Bigint *wasted_effort = NULL;
- p51 = mult(p5, p5);
- if (!p51) {
- Bfree(b);
- return NULL;
- }
- PR_Lock(p5s_lock);
- if (!p5->next) {
- p5->next = p51;
- p51->next = 0;
- } else {
- wasted_effort = p51;
- p51 = p5->next;
- }
- PR_Unlock(p5s_lock);
- if (wasted_effort) {
- Bfree(wasted_effort);
- }
-#else
- p51 = mult(p5,p5);
- if (!p51) {
- Bfree(b);
- return NULL;
- }
- p51->next = 0;
- p5->next = p51;
-#endif
- }
- p5 = p51;
- }
- return b;
-}
-
-/* Return b * 2^k. Deallocate the old b. k must be nonnegative.
- * NOTE: on memory failure, old b is deallocated. */
-static Bigint *lshift(Bigint *b, int32 k)
-{
- int32 i, k1, n, n1;
- Bigint *b1;
- ULong *x, *x1, *xe, z;
-
- n = k >> 5;
- k1 = b->k;
- n1 = n + b->wds + 1;
- for(i = b->maxwds; n1 > i; i <<= 1)
- k1++;
- b1 = Balloc(k1);
- if (!b1)
- goto done;
- x1 = b1->x;
- for(i = 0; i < n; i++)
- *x1++ = 0;
- x = b->x;
- xe = x + b->wds;
- if (k &= 0x1f) {
- k1 = 32 - k;
- z = 0;
- do {
- *x1++ = *x << k | z;
- z = *x++ >> k1;
- }
- while(x < xe);
- if ((*x1 = z) != 0)
- ++n1;
- }
- else do
- *x1++ = *x++;
- while(x < xe);
- b1->wds = n1 - 1;
-done:
- Bfree(b);
- return b1;
-}
-
-/* Return -1, 0, or 1 depending on whether a<b, a==b, or a>b, respectively. */
-static int32 cmp(Bigint *a, Bigint *b)
-{
- ULong *xa, *xa0, *xb, *xb0;
- int32 i, j;
-
- i = a->wds;
- j = b->wds;
-#ifdef DEBUG
- if (i > 1 && !a->x[i-1])
- Bug("cmp called with a->x[a->wds-1] == 0");
- if (j > 1 && !b->x[j-1])
- Bug("cmp called with b->x[b->wds-1] == 0");
-#endif
- if (i -= j)
- return i;
- xa0 = a->x;
- xa = xa0 + j;
- xb0 = b->x;
- xb = xb0 + j;
- for(;;) {
- if (*--xa != *--xb)
- return *xa < *xb ? -1 : 1;
- if (xa <= xa0)
- break;
- }
- return 0;
-}
-
-static Bigint *diff(Bigint *a, Bigint *b)
-{
- Bigint *c;
- int32 i, wa, wb;
- ULong *xa, *xae, *xb, *xbe, *xc;
-#ifdef ULLong
- ULLong borrow, y;
-#else
- ULong borrow, y;
- ULong z;
-#endif
-
- i = cmp(a,b);
- if (!i) {
- c = Balloc(0);
- if (!c)
- return NULL;
- c->wds = 1;
- c->x[0] = 0;
- return c;
- }
- if (i < 0) {
- c = a;
- a = b;
- b = c;
- i = 1;
- }
- else
- i = 0;
- c = Balloc(a->k);
- if (!c)
- return NULL;
- c->sign = i;
- wa = a->wds;
- xa = a->x;
- xae = xa + wa;
- wb = b->wds;
- xb = b->x;
- xbe = xb + wb;
- xc = c->x;
- borrow = 0;
-#ifdef ULLong
- do {
- y = (ULLong)*xa++ - *xb++ - borrow;
- borrow = y >> 32 & 1UL;
- *xc++ = (ULong)(y & 0xffffffffUL);
- }
- while(xb < xbe);
- while(xa < xae) {
- y = *xa++ - borrow;
- borrow = y >> 32 & 1UL;
- *xc++ = (ULong)(y & 0xffffffffUL);
- }
-#else
- do {
- y = (*xa & 0xffff) - (*xb & 0xffff) - borrow;
- borrow = (y & 0x10000) >> 16;
- z = (*xa++ >> 16) - (*xb++ >> 16) - borrow;
- borrow = (z & 0x10000) >> 16;
- Storeinc(xc, z, y);
- }
- while(xb < xbe);
- while(xa < xae) {
- y = (*xa & 0xffff) - borrow;
- borrow = (y & 0x10000) >> 16;
- z = (*xa++ >> 16) - borrow;
- borrow = (z & 0x10000) >> 16;
- Storeinc(xc, z, y);
- }
-#endif
- while(!*--xc)
- wa--;
- c->wds = wa;
- return c;
-}
-
-/* Return the absolute difference between x and the adjacent greater-magnitude double number (ignoring exponent overflows). */
-static double ulp(double x)
-{
- register Long L;
- double a;
-
- L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1;
-#ifndef Sudden_Underflow
- if (L > 0) {
-#endif
- set_word0(a, L);
- set_word1(a, 0);
-#ifndef Sudden_Underflow
- }
- else {
- L = -L >> Exp_shift;
- if (L < Exp_shift) {
- set_word0(a, 0x80000 >> L);
- set_word1(a, 0);
- }
- else {
- set_word0(a, 0);
- L -= Exp_shift;
- set_word1(a, L >= 31 ? 1 : 1 << (31 - L));
- }
- }
-#endif
- return a;
-}
-
-
-static double b2d(Bigint *a, int32 *e)
-{
- ULong *xa, *xa0, w, y, z;
- int32 k;
- double d;
-#define d0 word0(d)
-#define d1 word1(d)
-#define set_d0(x) set_word0(d, x)
-#define set_d1(x) set_word1(d, x)
-
- xa0 = a->x;
- xa = xa0 + a->wds;
- y = *--xa;
-#ifdef DEBUG
- if (!y) Bug("zero y in b2d");
-#endif
- k = hi0bits(y);
- *e = 32 - k;
- if (k < Ebits) {
- set_d0(Exp_1 | y >> (Ebits - k));
- w = xa > xa0 ? *--xa : 0;
- set_d1(y << (32-Ebits + k) | w >> (Ebits - k));
- goto ret_d;
- }
- z = xa > xa0 ? *--xa : 0;
- if (k -= Ebits) {
- set_d0(Exp_1 | y << k | z >> (32 - k));
- y = xa > xa0 ? *--xa : 0;
- set_d1(z << k | y >> (32 - k));
- }
- else {
- set_d0(Exp_1 | y);
- set_d1(z);
- }
- ret_d:
-#undef d0
-#undef d1
-#undef set_d0
-#undef set_d1
- return d;
-}
-
-
-/* Convert d into the form b*2^e, where b is an odd integer. b is the returned
- * Bigint and e is the returned binary exponent. Return the number of significant
- * bits in b in bits. d must be finite and nonzero. */
-static Bigint *d2b(double d, int32 *e, int32 *bits)
-{
- Bigint *b;
- int32 de, i, k;
- ULong *x, y, z;
-#define d0 word0(d)
-#define d1 word1(d)
-#define set_d0(x) set_word0(d, x)
-#define set_d1(x) set_word1(d, x)
-
- b = Balloc(1);
- if (!b)
- return NULL;
- x = b->x;
-
- z = d0 & Frac_mask;
- set_d0(d0 & 0x7fffffff); /* clear sign bit, which we ignore */
-#ifdef Sudden_Underflow
- de = (int32)(d0 >> Exp_shift);
- z |= Exp_msk11;
-#else
- if ((de = (int32)(d0 >> Exp_shift)) != 0)
- z |= Exp_msk1;
-#endif
- if ((y = d1) != 0) {
- if ((k = lo0bits(&y)) != 0) {
- x[0] = y | z << (32 - k);
- z >>= k;
- }
- else
- x[0] = y;
- i = b->wds = (x[1] = z) ? 2 : 1;
- }
- else {
- JS_ASSERT(z);
- k = lo0bits(&z);
- x[0] = z;
- i = b->wds = 1;
- k += 32;
- }
-#ifndef Sudden_Underflow
- if (de) {
-#endif
- *e = de - Bias - (P-1) + k;
- *bits = P - k;
-#ifndef Sudden_Underflow
- }
- else {
- *e = de - Bias - (P-1) + 1 + k;
- *bits = 32*i - hi0bits(x[i-1]);
- }
-#endif
- return b;
-}
-#undef d0
-#undef d1
-#undef set_d0
-#undef set_d1
-
-
-static double ratio(Bigint *a, Bigint *b)
-{
- double da, db;
- int32 k, ka, kb;
-
- da = b2d(a, &ka);
- db = b2d(b, &kb);
- k = ka - kb + 32*(a->wds - b->wds);
- if (k > 0)
- set_word0(da, word0(da) + k*Exp_msk1);
- else {
- k = -k;
- set_word0(db, word0(db) + k*Exp_msk1);
- }
- return da / db;
-}
-
-static CONST double
-tens[] = {
- 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
- 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
- 1e20, 1e21, 1e22
-};
-
-static CONST double bigtens[] = { 1e16, 1e32, 1e64, 1e128, 1e256 };
-static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128,
-#ifdef Avoid_Underflow
- 9007199254740992.e-256
-#else
- 1e-256
-#endif
- };
-/* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */
-/* flag unnecessarily. It leads to a song and dance at the end of strtod. */
-#define Scale_Bit 0x10
-#define n_bigtens 5
-
-
-#ifdef INFNAN_CHECK
-
-#ifndef NAN_WORD0
-#define NAN_WORD0 0x7ff80000
-#endif
-
-#ifndef NAN_WORD1
-#define NAN_WORD1 0
-#endif
-
-static int match(CONST char **sp, char *t)
-{
- int c, d;
- CONST char *s = *sp;
-
- while(d = *t++) {
- if ((c = *++s) >= 'A' && c <= 'Z')
- c += 'a' - 'A';
- if (c != d)
- return 0;
- }
- *sp = s + 1;
- return 1;
- }
-#endif /* INFNAN_CHECK */
-
-
-#ifdef JS_THREADSAFE
-static JSBool initialized = JS_FALSE;
-
-/* hacked replica of nspr _PR_InitDtoa */
-static void InitDtoa(void)
-{
- freelist_lock = PR_NewLock();
- p5s_lock = PR_NewLock();
- initialized = JS_TRUE;
-}
-#endif
-
-void js_FinishDtoa(void)
-{
- int count;
- Bigint *temp;
-
-#ifdef JS_THREADSAFE
- if (initialized == JS_TRUE) {
- PR_DestroyLock(freelist_lock);
- PR_DestroyLock(p5s_lock);
- initialized = JS_FALSE;
- }
-#endif
-
- /* clear down the freelist array and p5s */
-
- /* static Bigint *freelist[Kmax+1]; */
- for (count = 0; count <= Kmax; count++) {
- Bigint **listp = &freelist[count];
- while ((temp = *listp) != NULL) {
- *listp = temp->next;
- free(temp);
- }
- freelist[count] = NULL;
- }
-
- /* static Bigint *p5s; */
- while (p5s) {
- temp = p5s;
- p5s = p5s->next;
- free(temp);
- }
-}
-
-/* nspr2 watcom bug ifdef omitted */
-
-JS_FRIEND_API(double)
-JS_strtod(CONST char *s00, char **se, int *err)
-{
- int32 scale;
- int32 bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, dsign,
- e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign;
- CONST char *s, *s0, *s1;
- double aadj, aadj1, adj, rv, rv0;
- Long L;
- ULong y, z;
- Bigint *bb, *bb1, *bd, *bd0, *bs, *delta;
-
- SET_FPU();
-
- *err = 0;
-
- bb = bd = bs = delta = NULL;
- sign = nz0 = nz = 0;
- rv = 0.;
-
- /* Locking for Balloc's shared buffers that will be used in this block */
- ACQUIRE_DTOA_LOCK();
-
- for(s = s00;;s++) switch(*s) {
- case '-':
- sign = 1;
- /* no break */
- case '+':
- if (*++s)
- goto break2;
- /* no break */
- case 0:
- s = s00;
- goto ret;
- case '\t':
- case '\n':
- case '\v':
- case '\f':
- case '\r':
- case ' ':
- continue;
- default:
- goto break2;
- }
-break2:
-
- if (*s == '0') {
- nz0 = 1;
- while(*++s == '0') ;
- if (!*s)
- goto ret;
- }
- s0 = s;
- y = z = 0;
- for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)
- if (nd < 9)
- y = 10*y + c - '0';
- else if (nd < 16)
- z = 10*z + c - '0';
- nd0 = nd;
- if (c == '.') {
- c = *++s;
- if (!nd) {
- for(; c == '0'; c = *++s)
- nz++;
- if (c > '0' && c <= '9') {
- s0 = s;
- nf += nz;
- nz = 0;
- goto have_dig;
- }
- goto dig_done;
- }
- for(; c >= '0' && c <= '9'; c = *++s) {
- have_dig:
- nz++;
- if (c -= '0') {
- nf += nz;
- for(i = 1; i < nz; i++)
- if (nd++ < 9)
- y *= 10;
- else if (nd <= DBL_DIG + 1)
- z *= 10;
- if (nd++ < 9)
- y = 10*y + c;
- else if (nd <= DBL_DIG + 1)
- z = 10*z + c;
- nz = 0;
- }
- }
- }
-dig_done:
- e = 0;
- if (c == 'e' || c == 'E') {
- if (!nd && !nz && !nz0) {
- s = s00;
- goto ret;
- }
- s00 = s;
- esign = 0;
- switch(c = *++s) {
- case '-':
- esign = 1;
- case '+':
- c = *++s;
- }
- if (c >= '0' && c <= '9') {
- while(c == '0')
- c = *++s;
- if (c > '0' && c <= '9') {
- L = c - '0';
- s1 = s;
- while((c = *++s) >= '0' && c <= '9')
- L = 10*L + c - '0';
- if (s - s1 > 8 || L > 19999)
- /* Avoid confusion from exponents
- * so large that e might overflow.
- */
- e = 19999; /* safe for 16 bit ints */
- else
- e = (int32)L;
- if (esign)
- e = -e;
- }
- else
- e = 0;
- }
- else
- s = s00;
- }
- if (!nd) {
- if (!nz && !nz0) {
-#ifdef INFNAN_CHECK
- /* Check for Nan and Infinity */
- switch(c) {
- case 'i':
- case 'I':
- if (match(&s,"nfinity")) {
- word0(rv) = 0x7ff00000;
- word1(rv) = 0;
- goto ret;
- }
- break;
- case 'n':
- case 'N':
- if (match(&s, "an")) {
- word0(rv) = NAN_WORD0;
- word1(rv) = NAN_WORD1;
- goto ret;
- }
- }
-#endif /* INFNAN_CHECK */
- s = s00;
- }
- goto ret;
- }
- e1 = e -= nf;
-
- /* Now we have nd0 digits, starting at s0, followed by a
- * decimal point, followed by nd-nd0 digits. The number we're
- * after is the integer represented by those digits times
- * 10**e */
-
- if (!nd0)
- nd0 = nd;
- k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;
- rv = y;
- if (k > 9)
- rv = tens[k - 9] * rv + z;
- bd0 = 0;
- if (nd <= DBL_DIG
-#ifndef RND_PRODQUOT
- && FLT_ROUNDS == 1
-#endif
- ) {
- if (!e)
- goto ret;
- if (e > 0) {
- if (e <= Ten_pmax) {
- /* rv = */ rounded_product(rv, tens[e]);
- goto ret;
- }
- i = DBL_DIG - nd;
- if (e <= Ten_pmax + i) {
- /* A fancier test would sometimes let us do
- * this for larger i values.
- */
- e -= i;
- rv *= tens[i];
- /* rv = */ rounded_product(rv, tens[e]);
- goto ret;
- }
- }
-#ifndef Inaccurate_Divide
- else if (e >= -Ten_pmax) {
- /* rv = */ rounded_quotient(rv, tens[-e]);
- goto ret;
- }
-#endif
- }
- e1 += nd - k;
-
- scale = 0;
-
- /* Get starting approximation = rv * 10**e1 */
-
- if (e1 > 0) {
- if ((i = e1 & 15) != 0)
- rv *= tens[i];
- if (e1 &= ~15) {
- if (e1 > DBL_MAX_10_EXP) {
- ovfl:
- *err = JS_DTOA_ERANGE;
-#ifdef __STDC__
- rv = HUGE_VAL;
-#else
- /* Can't trust HUGE_VAL */
- word0(rv) = Exp_mask;
- word1(rv) = 0;
-#endif
- if (bd0)
- goto retfree;
- goto ret;
- }
- e1 >>= 4;
- for(j = 0; e1 > 1; j++, e1 >>= 1)
- if (e1 & 1)
- rv *= bigtens[j];
- /* The last multiplication could overflow. */
- set_word0(rv, word0(rv) - P*Exp_msk1);
- rv *= bigtens[j];
- if ((z = word0(rv) & Exp_mask) > Exp_msk1*(DBL_MAX_EXP+Bias-P))
- goto ovfl;
- if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) {
- /* set to largest number */
- /* (Can't trust DBL_MAX) */
- set_word0(rv, Big0);
- set_word1(rv, Big1);
- }
- else
- set_word0(rv, word0(rv) + P*Exp_msk1);
- }
- }
- else if (e1 < 0) {
- e1 = -e1;
- if ((i = e1 & 15) != 0)
- rv /= tens[i];
- if (e1 &= ~15) {
- e1 >>= 4;
- if (e1 >= 1 << n_bigtens)
- goto undfl;
-#ifdef Avoid_Underflow
- if (e1 & Scale_Bit)
- scale = P;
- for(j = 0; e1 > 0; j++, e1 >>= 1)
- if (e1 & 1)
- rv *= tinytens[j];
- if (scale && (j = P + 1 - ((word0(rv) & Exp_mask)
- >> Exp_shift)) > 0) {
- /* scaled rv is denormal; zap j low bits */
- if (j >= 32) {
- set_word1(rv, 0);
- set_word0(rv, word0(rv) & (0xffffffff << (j-32)));
- if (!word0(rv))
- set_word0(rv, 1);
- }
- else
- set_word1(rv, word1(rv) & (0xffffffff << j));
- }
-#else
- for(j = 0; e1 > 1; j++, e1 >>= 1)
- if (e1 & 1)
- rv *= tinytens[j];
- /* The last multiplication could underflow. */
- rv0 = rv;
- rv *= tinytens[j];
- if (!rv) {
- rv = 2.*rv0;
- rv *= tinytens[j];
-#endif
- if (!rv) {
- undfl:
- rv = 0.;
- *err = JS_DTOA_ERANGE;
- if (bd0)
- goto retfree;
- goto ret;
- }
-#ifndef Avoid_Underflow
- set_word0(rv, Tiny0);
- set_word1(rv, Tiny1);
- /* The refinement below will clean
- * this approximation up.
- */
- }
-#endif
- }
- }
-
- /* Now the hard part -- adjusting rv to the correct value.*/
-
- /* Put digits into bd: true value = bd * 10^e */
-
- bd0 = s2b(s0, nd0, nd, y);
- if (!bd0)
- goto nomem;
-
- for(;;) {
- bd = Balloc(bd0->k);
- if (!bd)
- goto nomem;
- Bcopy(bd, bd0);
- bb = d2b(rv, &bbe, &bbbits); /* rv = bb * 2^bbe */
- if (!bb)
- goto nomem;
- bs = i2b(1);
- if (!bs)
- goto nomem;
-
- if (e >= 0) {
- bb2 = bb5 = 0;
- bd2 = bd5 = e;
- }
- else {
- bb2 = bb5 = -e;
- bd2 = bd5 = 0;
- }
- if (bbe >= 0)
- bb2 += bbe;
- else
- bd2 -= bbe;
- bs2 = bb2;
-#ifdef Sudden_Underflow
- j = P + 1 - bbbits;
-#else
-#ifdef Avoid_Underflow
- j = bbe - scale;
-#else
- j = bbe;
-#endif
- i = j + bbbits - 1; /* logb(rv) */
- if (i < Emin) /* denormal */
- j += P - Emin;
- else
- j = P + 1 - bbbits;
-#endif
- bb2 += j;
- bd2 += j;
-#ifdef Avoid_Underflow
- bd2 += scale;
-#endif
- i = bb2 < bd2 ? bb2 : bd2;
- if (i > bs2)
- i = bs2;
- if (i > 0) {
- bb2 -= i;
- bd2 -= i;
- bs2 -= i;
- }
- if (bb5 > 0) {
- bs = pow5mult(bs, bb5);
- if (!bs)
- goto nomem;
- bb1 = mult(bs, bb);
- if (!bb1)
- goto nomem;
- Bfree(bb);
- bb = bb1;
- }
- if (bb2 > 0) {
- bb = lshift(bb, bb2);
- if (!bb)
- goto nomem;
- }
- if (bd5 > 0) {
- bd = pow5mult(bd, bd5);
- if (!bd)
- goto nomem;
- }
- if (bd2 > 0) {
- bd = lshift(bd, bd2);
- if (!bd)
- goto nomem;
- }
- if (bs2 > 0) {
- bs = lshift(bs, bs2);
- if (!bs)
- goto nomem;
- }
- delta = diff(bb, bd);
- if (!delta)
- goto nomem;
- dsign = delta->sign;
- delta->sign = 0;
- i = cmp(delta, bs);
- if (i < 0) {
- /* Error is less than half an ulp -- check for
- * special case of mantissa a power of two.
- */
- if (dsign || word1(rv) || word0(rv) & Bndry_mask
-#ifdef Avoid_Underflow
- || (word0(rv) & Exp_mask) <= Exp_msk1 + P*Exp_msk1
-#else
- || (word0(rv) & Exp_mask) <= Exp_msk1
-#endif
- ) {
-#ifdef Avoid_Underflow
- if (!delta->x[0] && delta->wds == 1)
- dsign = 2;
-#endif
- break;
- }
- delta = lshift(delta,Log2P);
- if (!delta)
- goto nomem;
- if (cmp(delta, bs) > 0)
- goto drop_down;
- break;
- }
- if (i == 0) {
- /* exactly half-way between */
- if (dsign) {
- if ((word0(rv) & Bndry_mask1) == Bndry_mask1
- && word1(rv) == 0xffffffff) {
- /*boundary case -- increment exponent*/
- set_word0(rv, (word0(rv) & Exp_mask) + Exp_msk1);
- set_word1(rv, 0);
-#ifdef Avoid_Underflow
- dsign = 0;
-#endif
- break;
- }
- }
- else if (!(word0(rv) & Bndry_mask) && !word1(rv)) {
-#ifdef Avoid_Underflow
- dsign = 2;
-#endif
- drop_down:
- /* boundary case -- decrement exponent */
-#ifdef Sudden_Underflow
- L = word0(rv) & Exp_mask;
- if (L <= Exp_msk1)
- goto undfl;
- L -= Exp_msk1;
-#else
- L = (word0(rv) & Exp_mask) - Exp_msk1;
-#endif
- set_word0(rv, L | Bndry_mask1);
- set_word1(rv, 0xffffffff);
- break;
- }
-#ifndef ROUND_BIASED
- if (!(word1(rv) & LSB))
- break;
-#endif
- if (dsign)
- rv += ulp(rv);
-#ifndef ROUND_BIASED
- else {
- rv -= ulp(rv);
-#ifndef Sudden_Underflow
- if (!rv)
- goto undfl;
-#endif
- }
-#ifdef Avoid_Underflow
- dsign = 1 - dsign;
-#endif
-#endif
- break;
- }
- if ((aadj = ratio(delta, bs)) <= 2.) {
- if (dsign)
- aadj = aadj1 = 1.;
- else if (word1(rv) || word0(rv) & Bndry_mask) {
-#ifndef Sudden_Underflow
- if (word1(rv) == Tiny1 && !word0(rv))
- goto undfl;
-#endif
- aadj = 1.;
- aadj1 = -1.;
- }
- else {
- /* special case -- power of FLT_RADIX to be */
- /* rounded down... */
-
- if (aadj < 2./FLT_RADIX)
- aadj = 1./FLT_RADIX;
- else
- aadj *= 0.5;
- aadj1 = -aadj;
- }
- }
- else {
- aadj *= 0.5;
- aadj1 = dsign ? aadj : -aadj;
-#ifdef Check_FLT_ROUNDS
- switch(FLT_ROUNDS) {
- case 2: /* towards +infinity */
- aadj1 -= 0.5;
- break;
- case 0: /* towards 0 */
- case 3: /* towards -infinity */
- aadj1 += 0.5;
- }
-#else
- if (FLT_ROUNDS == 0)
- aadj1 += 0.5;
-#endif
- }
- y = word0(rv) & Exp_mask;
-
- /* Check for overflow */
-
- if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
- rv0 = rv;
- set_word0(rv, word0(rv) - P*Exp_msk1);
- adj = aadj1 * ulp(rv);
- rv += adj;
- if ((word0(rv) & Exp_mask) >=
- Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
- if (word0(rv0) == Big0 && word1(rv0) == Big1)
- goto ovfl;
- set_word0(rv, Big0);
- set_word1(rv, Big1);
- goto cont;
- }
- else
- set_word0(rv, word0(rv) + P*Exp_msk1);
- }
- else {
-#ifdef Sudden_Underflow
- if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
- rv0 = rv;
- set_word0(rv, word0(rv) + P*Exp_msk1);
- adj = aadj1 * ulp(rv);
- rv += adj;
- if ((word0(rv) & Exp_mask) <= P*Exp_msk1)
- {
- if (word0(rv0) == Tiny0
- && word1(rv0) == Tiny1)
- goto undfl;
- set_word0(rv, Tiny0);
- set_word1(rv, Tiny1);
- goto cont;
- }
- else
- set_word0(rv, word0(rv) - P*Exp_msk1);
- }
- else {
- adj = aadj1 * ulp(rv);
- rv += adj;
- }
-#else
- /* Compute adj so that the IEEE rounding rules will
- * correctly round rv + adj in some half-way cases.
- * If rv * ulp(rv) is denormalized (i.e.,
- * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid
- * trouble from bits lost to denormalization;
- * example: 1.2e-307 .
- */
-#ifdef Avoid_Underflow
- if (y <= P*Exp_msk1 && aadj > 1.)
-#else
- if (y <= (P-1)*Exp_msk1 && aadj > 1.)
-#endif
- {
- aadj1 = (double)(int32)(aadj + 0.5);
- if (!dsign)
- aadj1 = -aadj1;
- }
-#ifdef Avoid_Underflow
- if (scale && y <= P*Exp_msk1)
- set_word0(aadj1, word0(aadj1) + (P+1)*Exp_msk1 - y);
-#endif
- adj = aadj1 * ulp(rv);
- rv += adj;
-#endif
- }
- z = word0(rv) & Exp_mask;
-#ifdef Avoid_Underflow
- if (!scale)
-#endif
- if (y == z) {
- /* Can we stop now? */
- L = (Long)aadj;
- aadj -= L;
- /* The tolerances below are conservative. */
- if (dsign || word1(rv) || word0(rv) & Bndry_mask) {
- if (aadj < .4999999 || aadj > .5000001)
- break;
- }
- else if (aadj < .4999999/FLT_RADIX)
- break;
- }
- cont:
- Bfree(bb);
- Bfree(bd);
- Bfree(bs);
- Bfree(delta);
- bb = bd = bs = delta = NULL;
- }
-#ifdef Avoid_Underflow
- if (scale) {
- set_word0(rv0, Exp_1 - P*Exp_msk1);
- set_word1(rv0, 0);
- if ((word0(rv) & Exp_mask) <= P*Exp_msk1
- && word1(rv) & 1
- && dsign != 2) {
- if (dsign) {
-#ifdef Sudden_Underflow
- /* rv will be 0, but this would give the */
- /* right result if only rv *= rv0 worked. */
- set_word0(rv, word0(rv) + P*Exp_msk1);
- set_word0(rv0, Exp_1 - 2*P*Exp_msk1);
-#endif
- rv += ulp(rv);
- }
- else
- set_word1(rv, word1(rv) & ~1);
- }
- rv *= rv0;
- }
-#endif /* Avoid_Underflow */
-retfree:
- Bfree(bb);
- Bfree(bd);
- Bfree(bs);
- Bfree(bd0);
- Bfree(delta);
-ret:
- RELEASE_DTOA_LOCK();
- if (se)
- *se = (char *)s;
- rv0 = sign ? -rv : rv;
- goto ret1;
-
-nomem:
- Bfree(bb);
- Bfree(bd);
- Bfree(bs);
- Bfree(bd0);
- Bfree(delta);
- *err = JS_DTOA_ENOMEM;
- rv0 = 0;
-
-ret1:
- RESTORE_FPU();
- return rv0;
-}
-
-
-/* Return floor(b/2^k) and set b to be the remainder. The returned quotient must be less than 2^32. */
-static uint32 quorem2(Bigint *b, int32 k)
-{
- ULong mask;
- ULong result;
- ULong *bx, *bxe;
- int32 w;
- int32 n = k >> 5;
- k &= 0x1F;
- mask = (1<<k) - 1;
-
- w = b->wds - n;
- if (w <= 0)
- return 0;
- JS_ASSERT(w <= 2);
- bx = b->x;
- bxe = bx + n;
- result = *bxe >> k;
- *bxe &= mask;
- if (w == 2) {
- JS_ASSERT(!(bxe[1] & ~mask));
- if (k)
- result |= bxe[1] << (32 - k);
- }
- n++;
- while (!*bxe && bxe != bx) {
- n--;
- bxe--;
- }
- b->wds = n;
- return result;
-}
-
-/* Return floor(b/S) and set b to be the remainder. As added restrictions, b must not have
- * more words than S, the most significant word of S must not start with a 1 bit, and the
- * returned quotient must be less than 36. */
-static int32 quorem(Bigint *b, Bigint *S)
-{
- int32 n;
- ULong *bx, *bxe, q, *sx, *sxe;
-#ifdef ULLong
- ULLong borrow, carry, y, ys;
-#else
- ULong borrow, carry, y, ys;
- ULong si, z, zs;
-#endif
-
- n = S->wds;
- JS_ASSERT(b->wds <= n);
- if (b->wds < n)
- return 0;
- sx = S->x;
- sxe = sx + --n;
- bx = b->x;
- bxe = bx + n;
- JS_ASSERT(*sxe <= 0x7FFFFFFF);
- q = *bxe / (*sxe + 1); /* ensure q <= true quotient */
- JS_ASSERT(q < 36);
- if (q) {
- borrow = 0;
- carry = 0;
- do {
-#ifdef ULLong
- ys = *sx++ * (ULLong)q + carry;
- carry = ys >> 32;
- y = *bx - (ys & 0xffffffffUL) - borrow;
- borrow = y >> 32 & 1UL;
- *bx++ = (ULong)(y & 0xffffffffUL);
-#else
- si = *sx++;
- ys = (si & 0xffff) * q + carry;
- zs = (si >> 16) * q + (ys >> 16);
- carry = zs >> 16;
- y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
- borrow = (y & 0x10000) >> 16;
- z = (*bx >> 16) - (zs & 0xffff) - borrow;
- borrow = (z & 0x10000) >> 16;
- Storeinc(bx, z, y);
-#endif
- }
- while(sx <= sxe);
- if (!*bxe) {
- bx = b->x;
- while(--bxe > bx && !*bxe)
- --n;
- b->wds = n;
- }
- }
- if (cmp(b, S) >= 0) {
- q++;
- borrow = 0;
- carry = 0;
- bx = b->x;
- sx = S->x;
- do {
-#ifdef ULLong
- ys = *sx++ + carry;
- carry = ys >> 32;
- y = *bx - (ys & 0xffffffffUL) - borrow;
- borrow = y >> 32 & 1UL;
- *bx++ = (ULong)(y & 0xffffffffUL);
-#else
- si = *sx++;
- ys = (si & 0xffff) + carry;
- zs = (si >> 16) + (ys >> 16);
- carry = zs >> 16;
- y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
- borrow = (y & 0x10000) >> 16;
- z = (*bx >> 16) - (zs & 0xffff) - borrow;
- borrow = (z & 0x10000) >> 16;
- Storeinc(bx, z, y);
-#endif
- } while(sx <= sxe);
- bx = b->x;
- bxe = bx + n;
- if (!*bxe) {
- while(--bxe > bx && !*bxe)
- --n;
- b->wds = n;
- }
- }
- return (int32)q;
-}
-
-/* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.
- *
- * Inspired by "How to Print Floating-Point Numbers Accurately" by
- * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 92-101].
- *
- * Modifications:
- * 1. Rather than iterating, we use a simple numeric overestimate
- * to determine k = floor(log10(d)). We scale relevant
- * quantities using O(log2(k)) rather than O(k) multiplications.
- * 2. For some modes > 2 (corresponding to ecvt and fcvt), we don't
- * try to generate digits strictly left to right. Instead, we
- * compute with fewer bits and propagate the carry if necessary
- * when rounding the final digit up. This is often faster.
- * 3. Under the assumption that input will be rounded nearest,
- * mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22.
- * That is, we allow equality in stopping tests when the
- * round-nearest rule will give the same floating-point value
- * as would satisfaction of the stopping test with strict
- * inequality.
- * 4. We remove common factors of powers of 2 from relevant
- * quantities.
- * 5. When converting floating-point integers less than 1e16,
- * we use floating-point arithmetic rather than resorting
- * to multiple-precision integers.
- * 6. When asked to produce fewer than 15 digits, we first try
- * to get by with floating-point arithmetic; we resort to
- * multiple-precision integer arithmetic only if we cannot
- * guarantee that the floating-point calculation has given
- * the correctly rounded result. For k requested digits and
- * "uniformly" distributed input, the probability is
- * something like 10^(k-15) that we must resort to the Long
- * calculation.
- */
-
-/* Always emits at least one digit. */
-/* If biasUp is set, then rounding in modes 2 and 3 will round away from zero
- * when the number is exactly halfway between two representable values. For example,
- * rounding 2.5 to zero digits after the decimal point will return 3 and not 2.
- * 2.49 will still round to 2, and 2.51 will still round to 3. */
-/* bufsize should be at least 20 for modes 0 and 1. For the other modes,
- * bufsize should be two greater than the maximum number of output characters expected. */
-static JSBool
-js_dtoa(double d, int mode, JSBool biasUp, int ndigits,
- int *decpt, int *sign, char **rve, char *buf, size_t bufsize)
-{
- /* Arguments ndigits, decpt, sign are similar to those
- of ecvt and fcvt; trailing zeros are suppressed from
- the returned string. If not null, *rve is set to point
- to the end of the return value. If d is +-Infinity or NaN,
- then *decpt is set to 9999.
-
- mode:
- 0 ==> shortest string that yields d when read in
- and rounded to nearest.
- 1 ==> like 0, but with Steele & White stopping rule;
- e.g. with IEEE P754 arithmetic , mode 0 gives
- 1e23 whereas mode 1 gives 9.999999999999999e22.
- 2 ==> max(1,ndigits) significant digits. This gives a
- return value similar to that of ecvt, except
- that trailing zeros are suppressed.
- 3 ==> through ndigits past the decimal point. This
- gives a return value similar to that from fcvt,
- except that trailing zeros are suppressed, and
- ndigits can be negative.
- 4-9 should give the same return values as 2-3, i.e.,
- 4 <= mode <= 9 ==> same return as mode
- 2 + (mode & 1). These modes are mainly for
- debugging; often they run slower but sometimes
- faster than modes 2-3.
- 4,5,8,9 ==> left-to-right digit generation.
- 6-9 ==> don't try fast floating-point estimate
- (if applicable).
-
- Values of mode other than 0-9 are treated as mode 0.
-
- Sufficient space is allocated to the return value
- to hold the suppressed trailing zeros.
- */
-
- int32 bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1,
- j, j1, k, k0, k_check, leftright, m2, m5, s2, s5,
- spec_case, try_quick;
- Long L;
-#ifndef Sudden_Underflow
- int32 denorm;
- ULong x;
-#endif
- Bigint *b, *b1, *delta, *mlo, *mhi, *S;
- double d2, ds, eps;
- char *s;
- JSBool ok;
-
- SET_FPU();
-
- if (word0(d) & Sign_bit) {
- /* set sign for everything, including 0's and NaNs */
- *sign = 1;
- set_word0(d, word0(d) & ~Sign_bit); /* clear sign bit */
- }
- else
- *sign = 0;
-
- if ((word0(d) & Exp_mask) == Exp_mask) {
- /* Infinity or NaN */
- *decpt = 9999;
- s = !word1(d) && !(word0(d) & Frac_mask) ? "Infinity" : "NaN";
- if ((s[0] == 'I' && bufsize < 9) || (s[0] == 'N' && bufsize < 4)) {
- JS_ASSERT(JS_FALSE);
-/* JS_SetError(JS_BUFFER_OVERFLOW_ERROR, 0); */
- ok = JS_FALSE;
- goto ret2;
- }
- strcpy(buf, s);
- if (rve) {
- *rve = buf[3] ? buf + 8 : buf + 3;
- JS_ASSERT(**rve == '\0');
- }
- ok = JS_TRUE;
- goto ret2;
- }
-
- b = NULL; /* initialize for abort protection */
- S = NULL;
- mlo = mhi = NULL;
-
- if (!d) {
- no_digits:
- *decpt = 1;
- if (bufsize < 2) {
- JS_ASSERT(JS_FALSE);
-/* JS_SetError(JS_BUFFER_OVERFLOW_ERROR, 0); */
- ok = JS_FALSE;
- goto ret2;
- }
- buf[0] = '0'; buf[1] = '\0'; /* copy "0" to buffer */
- if (rve)
- *rve = buf + 1;
- /* We might have jumped to "no_digits" from below, so we need
- * to be sure to free the potentially allocated Bigints to avoid
- * memory leaks. */
- Bfree(b);
- Bfree(S);
- if (mlo != mhi)
- Bfree(mlo);
- Bfree(mhi);
- ok = JS_TRUE;
- goto ret2;
- }
-
- b = d2b(d, &be, &bbits);
- if (!b)
- goto nomem;
-#ifdef Sudden_Underflow
- i = (int32)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1));
-#else
- if ((i = (int32)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1))) != 0) {
-#endif
- d2 = d;
- set_word0(d2, word0(d2) & Frac_mask1);
- set_word0(d2, word0(d2) | Exp_11);
-
- /* log(x) ~=~ log(1.5) + (x-1.5)/1.5
- * log10(x) = log(x) / log(10)
- * ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
- * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
- *
- * This suggests computing an approximation k to log10(d) by
- *
- * k = (i - Bias)*0.301029995663981
- * + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );
- *
- * We want k to be too large rather than too small.
- * The error in the first-order Taylor series approximation
- * is in our favor, so we just round up the constant enough
- * to compensate for any error in the multiplication of
- * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077,
- * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14,
- * adding 1e-13 to the constant term more than suffices.
- * Hence we adjust the constant term to 0.1760912590558.
- * (We could get a more accurate k by invoking log10,
- * but this is probably not worthwhile.)
- */
-
- i -= Bias;
-#ifndef Sudden_Underflow
- denorm = 0;
- }
- else {
- /* d is denormalized */
-
- i = bbits + be + (Bias + (P-1) - 1);
- x = i > 32 ? word0(d) << (64 - i) | word1(d) >> (i - 32) : word1(d) << (32 - i);
- d2 = x;
- set_word0(d2, word0(d2) - 31*Exp_msk1); /* adjust exponent */
- i -= (Bias + (P-1) - 1) + 1;
- denorm = 1;
- }
-#endif
- /* At this point d = f*2^i, where 1 <= f < 2. d2 is an approximation of f. */
- ds = (d2-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
- k = (int32)ds;
- if (ds < 0. && ds != k)
- k--; /* want k = floor(ds) */
- k_check = 1;
- if (k >= 0 && k <= Ten_pmax) {
- if (d < tens[k])
- k--;
- k_check = 0;
- }
- /* At this point floor(log10(d)) <= k <= floor(log10(d))+1.
- If k_check is zero, we're guaranteed that k = floor(log10(d)). */
- j = bbits - i - 1;
- /* At this point d = b/2^j, where b is an odd integer. */
- if (j >= 0) {
- b2 = 0;
- s2 = j;
- }
- else {
- b2 = -j;
- s2 = 0;
- }
- if (k >= 0) {
- b5 = 0;
- s5 = k;
- s2 += k;
- }
- else {
- b2 -= k;
- b5 = -k;
- s5 = 0;
- }
- /* At this point d/10^k = (b * 2^b2 * 5^b5) / (2^s2 * 5^s5), where b is an odd integer,
- b2 >= 0, b5 >= 0, s2 >= 0, and s5 >= 0. */
- if (mode < 0 || mode > 9)
- mode = 0;
- try_quick = 1;
- if (mode > 5) {
- mode -= 4;
- try_quick = 0;
- }
- leftright = 1;
- ilim = ilim1 = 0;
- switch(mode) {
- case 0:
- case 1:
- ilim = ilim1 = -1;
- i = 18;
- ndigits = 0;
- break;
- case 2:
- leftright = 0;
- /* no break */
- case 4:
- if (ndigits <= 0)
- ndigits = 1;
- ilim = ilim1 = i = ndigits;
- break;
- case 3:
- leftright = 0;
- /* no break */
- case 5:
- i = ndigits + k + 1;
- ilim = i;
- ilim1 = i - 1;
- if (i <= 0)
- i = 1;
- }
- /* ilim is the maximum number of significant digits we want, based on k and ndigits. */
- /* ilim1 is the maximum number of significant digits we want, based on k and ndigits,
- when it turns out that k was computed too high by one. */
-
- /* Ensure space for at least i+1 characters, including trailing null. */
- if (bufsize <= (size_t)i) {
- Bfree(b);
- JS_ASSERT(JS_FALSE);
- ok = JS_FALSE;
- goto ret2;
- }
- s = buf;
-
- if (ilim >= 0 && ilim <= Quick_max && try_quick) {
-
- /* Try to get by with floating-point arithmetic. */
-
- i = 0;
- d2 = d;
- k0 = k;
- ilim0 = ilim;
- ieps = 2; /* conservative */
- /* Divide d by 10^k, keeping track of the roundoff error and avoiding overflows. */
- if (k > 0) {
- ds = tens[k&0xf];
- j = k >> 4;
- if (j & Bletch) {
- /* prevent overflows */
- j &= Bletch - 1;
- d /= bigtens[n_bigtens-1];
- ieps++;
- }
- for(; j; j >>= 1, i++)
- if (j & 1) {
- ieps++;
- ds *= bigtens[i];
- }
- d /= ds;
- }
- else if ((j1 = -k) != 0) {
- d *= tens[j1 & 0xf];
- for(j = j1 >> 4; j; j >>= 1, i++)
- if (j & 1) {
- ieps++;
- d *= bigtens[i];
- }
- }
- /* Check that k was computed correctly. */
- if (k_check && d < 1. && ilim > 0) {
- if (ilim1 <= 0)
- goto fast_failed;
- ilim = ilim1;
- k--;
- d *= 10.;
- ieps++;
- }
- /* eps bounds the cumulative error. */
- eps = ieps*d + 7.;
- set_word0(eps, word0(eps) - (P-1)*Exp_msk1);
- if (ilim == 0) {
- S = mhi = 0;
- d -= 5.;
- if (d > eps)
- goto one_digit;
- if (d < -eps)
- goto no_digits;
- goto fast_failed;
- }
-#ifndef No_leftright
- if (leftright) {
- /* Use Steele & White method of only
- * generating digits needed.
- */
- eps = 0.5/tens[ilim-1] - eps;
- for(i = 0;;) {
- L = (Long)d;
- d -= L;
- *s++ = '0' + (char)L;
- if (d < eps)
- goto ret1;
- if (1. - d < eps)
- goto bump_up;
- if (++i >= ilim)
- break;
- eps *= 10.;
- d *= 10.;
- }
- }
- else {
-#endif
- /* Generate ilim digits, then fix them up. */
- eps *= tens[ilim-1];
- for(i = 1;; i++, d *= 10.) {
- L = (Long)d;
- d -= L;
- *s++ = '0' + (char)L;
- if (i == ilim) {
- if (d > 0.5 + eps)
- goto bump_up;
- else if (d < 0.5 - eps) {
- while(*--s == '0') ;
- s++;
- goto ret1;
- }
- break;
- }
- }
-#ifndef No_leftright
- }
-#endif
- fast_failed:
- s = buf;
- d = d2;
- k = k0;
- ilim = ilim0;
- }
-
- /* Do we have a "small" integer? */
-
- if (be >= 0 && k <= Int_max) {
- /* Yes. */
- ds = tens[k];
- if (ndigits < 0 && ilim <= 0) {
- S = mhi = 0;
- if (ilim < 0 || d < 5*ds || (!biasUp && d == 5*ds))
- goto no_digits;
- goto one_digit;
- }
- for(i = 1;; i++) {
- L = (Long) (d / ds);
- d -= L*ds;
-#ifdef Check_FLT_ROUNDS
- /* If FLT_ROUNDS == 2, L will usually be high by 1 */
- if (d < 0) {
- L--;
- d += ds;
- }
-#endif
- *s++ = '0' + (char)L;
- if (i == ilim) {
- d += d;
- if ((d > ds) || (d == ds && (L & 1 || biasUp))) {
- bump_up:
- while(*--s == '9')
- if (s == buf) {
- k++;
- *s = '0';
- break;
- }
- ++*s++;
- }
- break;
- }
- if (!(d *= 10.))
- break;
- }
- goto ret1;
- }
-
- m2 = b2;
- m5 = b5;
- if (leftright) {
- if (mode < 2) {
- i =
-#ifndef Sudden_Underflow
- denorm ? be + (Bias + (P-1) - 1 + 1) :
-#endif
- 1 + P - bbits;
- /* i is 1 plus the number of trailing zero bits in d's significand. Thus,
- (2^m2 * 5^m5) / (2^(s2+i) * 5^s5) = (1/2 lsb of d)/10^k. */
- }
- else {
- j = ilim - 1;
- if (m5 >= j)
- m5 -= j;
- else {
- s5 += j -= m5;
- b5 += j;
- m5 = 0;
- }
- if ((i = ilim) < 0) {
- m2 -= i;
- i = 0;
- }
- /* (2^m2 * 5^m5) / (2^(s2+i) * 5^s5) = (1/2 * 10^(1-ilim))/10^k. */
- }
- b2 += i;
- s2 += i;
- mhi = i2b(1);
- if (!mhi)
- goto nomem;
- /* (mhi * 2^m2 * 5^m5) / (2^s2 * 5^s5) = one-half of last printed (when mode >= 2) or
- input (when mode < 2) significant digit, divided by 10^k. */
- }
- /* We still have d/10^k = (b * 2^b2 * 5^b5) / (2^s2 * 5^s5). Reduce common factors in
- b2, m2, and s2 without changing the equalities. */
- if (m2 > 0 && s2 > 0) {
- i = m2 < s2 ? m2 : s2;
- b2 -= i;
- m2 -= i;
- s2 -= i;
- }
-
- /* Fold b5 into b and m5 into mhi. */
- if (b5 > 0) {
- if (leftright) {
- if (m5 > 0) {
- mhi = pow5mult(mhi, m5);
- if (!mhi)
- goto nomem;
- b1 = mult(mhi, b);
- if (!b1)
- goto nomem;
- Bfree(b);
- b = b1;
- }
- if ((j = b5 - m5) != 0) {
- b = pow5mult(b, j);
- if (!b)
- goto nomem;
- }
- }
- else {
- b = pow5mult(b, b5);
- if (!b)
- goto nomem;
- }
- }
- /* Now we have d/10^k = (b * 2^b2) / (2^s2 * 5^s5) and
- (mhi * 2^m2) / (2^s2 * 5^s5) = one-half of last printed or input significant digit, divided by 10^k. */
-
- S = i2b(1);
- if (!S)
- goto nomem;
- if (s5 > 0) {
- S = pow5mult(S, s5);
- if (!S)
- goto nomem;
- }
- /* Now we have d/10^k = (b * 2^b2) / (S * 2^s2) and
- (mhi * 2^m2) / (S * 2^s2) = one-half of last printed or input significant digit, divided by 10^k. */
-
- /* Check for special case that d is a normalized power of 2. */
- spec_case = 0;
- if (mode < 2) {
- if (!word1(d) && !(word0(d) & Bndry_mask)
-#ifndef Sudden_Underflow
- && word0(d) & (Exp_mask & Exp_mask << 1)
-#endif
- ) {
- /* The special case. Here we want to be within a quarter of the last input
- significant digit instead of one half of it when the decimal output string's value is less than d. */
- b2 += Log2P;
- s2 += Log2P;
- spec_case = 1;
- }
- }
-
- /* Arrange for convenient computation of quotients:
- * shift left if necessary so divisor has 4 leading 0 bits.
- *
- * Perhaps we should just compute leading 28 bits of S once
- * and for all and pass them and a shift to quorem, so it
- * can do shifts and ors to compute the numerator for q.
- */
- if ((i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f) != 0)
- i = 32 - i;
- /* i is the number of leading zero bits in the most significant word of S*2^s2. */
- if (i > 4) {
- i -= 4;
- b2 += i;
- m2 += i;
- s2 += i;
- }
- else if (i < 4) {
- i += 28;
- b2 += i;
- m2 += i;
- s2 += i;
- }
- /* Now S*2^s2 has exactly four leading zero bits in its most significant word. */
- if (b2 > 0) {
- b = lshift(b, b2);
- if (!b)
- goto nomem;
- }
- if (s2 > 0) {
- S = lshift(S, s2);
- if (!S)
- goto nomem;
- }
- /* Now we have d/10^k = b/S and
- (mhi * 2^m2) / S = maximum acceptable error, divided by 10^k. */
- if (k_check) {
- if (cmp(b,S) < 0) {
- k--;
- b = multadd(b, 10, 0); /* we botched the k estimate */
- if (!b)
- goto nomem;
- if (leftright) {
- mhi = multadd(mhi, 10, 0);
- if (!mhi)
- goto nomem;
- }
- ilim = ilim1;
- }
- }
- /* At this point 1 <= d/10^k = b/S < 10. */
-
- if (ilim <= 0 && mode > 2) {
- /* We're doing fixed-mode output and d is less than the minimum nonzero output in this mode.
- Output either zero or the minimum nonzero output depending on which is closer to d. */
- if (ilim < 0)
- goto no_digits;
- S = multadd(S,5,0);
- if (!S)
- goto nomem;
- i = cmp(b,S);
- if (i < 0 || (i == 0 && !biasUp)) {
- /* Always emit at least one digit. If the number appears to be zero
- using the current mode, then emit one '0' digit and set decpt to 1. */
- /*no_digits:
- k = -1 - ndigits;
- goto ret; */
- goto no_digits;
- }
- one_digit:
- *s++ = '1';
- k++;
- goto ret;
- }
- if (leftright) {
- if (m2 > 0) {
- mhi = lshift(mhi, m2);
- if (!mhi)
- goto nomem;
- }
-
- /* Compute mlo -- check for special case
- * that d is a normalized power of 2.
- */
-
- mlo = mhi;
- if (spec_case) {
- mhi = Balloc(mhi->k);
- if (!mhi)
- goto nomem;
- Bcopy(mhi, mlo);
- mhi = lshift(mhi, Log2P);
- if (!mhi)
- goto nomem;
- }
- /* mlo/S = maximum acceptable error, divided by 10^k, if the output is less than d. */
- /* mhi/S = maximum acceptable error, divided by 10^k, if the output is greater than d. */
-
- for(i = 1;;i++) {
- dig = quorem(b,S) + '0';
- /* Do we yet have the shortest decimal string
- * that will round to d?
- */
- j = cmp(b, mlo);
- /* j is b/S compared with mlo/S. */
- delta = diff(S, mhi);
- if (!delta)
- goto nomem;
- j1 = delta->sign ? 1 : cmp(b, delta);
- Bfree(delta);
- /* j1 is b/S compared with 1 - mhi/S. */
-#ifndef ROUND_BIASED
- if (j1 == 0 && !mode && !(word1(d) & 1)) {
- if (dig == '9')
- goto round_9_up;
- if (j > 0)
- dig++;
- *s++ = (char)dig;
- goto ret;
- }
-#endif
- if ((j < 0) || (j == 0 && !mode
-#ifndef ROUND_BIASED
- && !(word1(d) & 1)
-#endif
- )) {
- if (j1 > 0) {
- /* Either dig or dig+1 would work here as the least significant decimal digit.
- Use whichever would produce a decimal value closer to d. */
- b = lshift(b, 1);
- if (!b)
- goto nomem;
- j1 = cmp(b, S);
- if (((j1 > 0) || (j1 == 0 && (dig & 1 || biasUp)))
- && (dig++ == '9'))
- goto round_9_up;
- }
- *s++ = (char)dig;
- goto ret;
- }
- if (j1 > 0) {
- if (dig == '9') { /* possible if i == 1 */
- round_9_up:
- *s++ = '9';
- goto roundoff;
- }
- *s++ = dig + 1;
- goto ret;
- }
- *s++ = (char)dig;
- if (i == ilim)
- break;
- b = multadd(b, 10, 0);
- if (!b)
- goto nomem;
- if (mlo == mhi) {
- mlo = mhi = multadd(mhi, 10, 0);
- if (!mhi)
- goto nomem;
- }
- else {
- mlo = multadd(mlo, 10, 0);
- if (!mlo)
- goto nomem;
- mhi = multadd(mhi, 10, 0);
- if (!mhi)
- goto nomem;
- }
- }
- }
- else
- for(i = 1;; i++) {
- *s++ = (char)(dig = quorem(b,S) + '0');
- if (i >= ilim)
- break;
- b = multadd(b, 10, 0);
- if (!b)
- goto nomem;
- }
-
- /* Round off last digit */
-
- b = lshift(b, 1);
- if (!b)
- goto nomem;
- j = cmp(b, S);
- if ((j > 0) || (j == 0 && (dig & 1 || biasUp))) {
- roundoff:
- while(*--s == '9')
- if (s == buf) {
- k++;
- *s++ = '1';
- goto ret;
- }
- ++*s++;
- }
- else {
- /* Strip trailing zeros */
- while(*--s == '0') ;
- s++;
- }
- ret:
- Bfree(S);
- if (mhi) {
- if (mlo && mlo != mhi)
- Bfree(mlo);
- Bfree(mhi);
- }
- ret1:
- Bfree(b);
- JS_ASSERT(s < buf + bufsize);
- *s = '\0';
- if (rve)
- *rve = s;
- *decpt = k + 1;
- ok = JS_TRUE;
- goto ret2;
-
-nomem:
- Bfree(S);
- if (mhi) {
- if (mlo && mlo != mhi)
- Bfree(mlo);
- Bfree(mhi);
- }
- Bfree(b);
- ok = JS_FALSE;
-
-ret2:
- RESTORE_FPU();
- return ok;
-}
-
-
-/* Mapping of JSDToStrMode -> js_dtoa mode */
-static const int dtoaModes[] = {
- 0, /* DTOSTR_STANDARD */
- 0, /* DTOSTR_STANDARD_EXPONENTIAL, */
- 3, /* DTOSTR_FIXED, */
- 2, /* DTOSTR_EXPONENTIAL, */
- 2}; /* DTOSTR_PRECISION */
-
-JS_FRIEND_API(char *)
-JS_dtostr(char *buffer, size_t bufferSize, JSDToStrMode mode, int precision, double d)
-{
- int decPt; /* Position of decimal point relative to first digit returned by js_dtoa */
- int sign; /* Nonzero if the sign bit was set in d */
- int nDigits; /* Number of significand digits returned by js_dtoa */
- char *numBegin = buffer+2; /* Pointer to the digits returned by js_dtoa; the +2 leaves space for */
- /* the sign and/or decimal point */
- char *numEnd; /* Pointer past the digits returned by js_dtoa */
- JSBool dtoaRet;
-
- JS_ASSERT(bufferSize >= (size_t)(mode <= DTOSTR_STANDARD_EXPONENTIAL ? DTOSTR_STANDARD_BUFFER_SIZE :
- DTOSTR_VARIABLE_BUFFER_SIZE(precision)));
-
- if (mode == DTOSTR_FIXED && (d >= 1e21 || d <= -1e21))
- mode = DTOSTR_STANDARD; /* Change mode here rather than below because the buffer may not be large enough to hold a large integer. */
-
- /* Locking for Balloc's shared buffers */
- ACQUIRE_DTOA_LOCK();
- dtoaRet = js_dtoa(d, dtoaModes[mode], mode >= DTOSTR_FIXED, precision, &decPt, &sign, &numEnd, numBegin, bufferSize-2);
- RELEASE_DTOA_LOCK();
- if (!dtoaRet)
- return 0;
-
- nDigits = numEnd - numBegin;
-
- /* If Infinity, -Infinity, or NaN, return the string regardless of the mode. */
- if (decPt != 9999) {
- JSBool exponentialNotation = JS_FALSE;
- int minNDigits = 0; /* Minimum number of significand digits required by mode and precision */
- char *p;
- char *q;
-
- switch (mode) {
- case DTOSTR_STANDARD:
- if (decPt < -5 || decPt > 21)
- exponentialNotation = JS_TRUE;
- else
- minNDigits = decPt;
- break;
-
- case DTOSTR_FIXED:
- if (precision >= 0)
- minNDigits = decPt + precision;
- else
- minNDigits = decPt;
- break;
-
- case DTOSTR_EXPONENTIAL:
- JS_ASSERT(precision > 0);
- minNDigits = precision;
- /* Fall through */
- case DTOSTR_STANDARD_EXPONENTIAL:
- exponentialNotation = JS_TRUE;
- break;
-
- case DTOSTR_PRECISION:
- JS_ASSERT(precision > 0);
- minNDigits = precision;
- if (decPt < -5 || decPt > precision)
- exponentialNotation = JS_TRUE;
- break;
- }
-
- /* If the number has fewer than minNDigits, pad it with zeros at the end */
- if (nDigits < minNDigits) {
- p = numBegin + minNDigits;
- nDigits = minNDigits;
- do {
- *numEnd++ = '0';
- } while (numEnd != p);
- *numEnd = '\0';
- }
-
- if (exponentialNotation) {
- /* Insert a decimal point if more than one significand digit */
- if (nDigits != 1) {
- numBegin--;
- numBegin[0] = numBegin[1];
- numBegin[1] = '.';
- }
- JS_snprintf(numEnd, bufferSize - (numEnd - buffer), "e%+d", decPt-1);
- } else if (decPt != nDigits) {
- /* Some kind of a fraction in fixed notation */
- JS_ASSERT(decPt <= nDigits);
- if (decPt > 0) {
- /* dd...dd . dd...dd */
- p = --numBegin;
- do {
- *p = p[1];
- p++;
- } while (--decPt);
- *p = '.';
- } else {
- /* 0 . 00...00dd...dd */
- p = numEnd;
- numEnd += 1 - decPt;
- q = numEnd;
- JS_ASSERT(numEnd < buffer + bufferSize);
- *numEnd = '\0';
- while (p != numBegin)
- *--q = *--p;
- for (p = numBegin + 1; p != q; p++)
- *p = '0';
- *numBegin = '.';
- *--numBegin = '0';
- }
- }
- }
-
- /* If negative and neither -0.0 nor NaN, output a leading '-'. */
- if (sign &&
- !(word0(d) == Sign_bit && word1(d) == 0) &&
- !((word0(d) & Exp_mask) == Exp_mask &&
- (word1(d) || (word0(d) & Frac_mask)))) {
- *--numBegin = '-';
- }
- return numBegin;
-}
-
-
-/* Let b = floor(b / divisor), and return the remainder. b must be nonnegative.
- * divisor must be between 1 and 65536.
- * This function cannot run out of memory. */
-static uint32
-divrem(Bigint *b, uint32 divisor)
-{
- int32 n = b->wds;
- uint32 remainder = 0;
- ULong *bx;
- ULong *bp;
-
- JS_ASSERT(divisor > 0 && divisor <= 65536);
-
- if (!n)
- return 0; /* b is zero */
- bx = b->x;
- bp = bx + n;
- do {
- ULong a = *--bp;
- ULong dividend = remainder << 16 | a >> 16;
- ULong quotientHi = dividend / divisor;
- ULong quotientLo;
-
- remainder = dividend - quotientHi*divisor;
- JS_ASSERT(quotientHi <= 0xFFFF && remainder < divisor);
- dividend = remainder << 16 | (a & 0xFFFF);
- quotientLo = dividend / divisor;
- remainder = dividend - quotientLo*divisor;
- JS_ASSERT(quotientLo <= 0xFFFF && remainder < divisor);
- *bp = quotientHi << 16 | quotientLo;
- } while (bp != bx);
- /* Decrease the size of the number if its most significant word is now zero. */
- if (bx[n-1] == 0)
- b->wds--;
- return remainder;
-}
-
-
-/* "-0.0000...(1073 zeros after decimal point)...0001\0" is the longest string that we could produce,
- * which occurs when printing -5e-324 in binary. We could compute a better estimate of the size of
- * the output string and malloc fewer bytes depending on d and base, but why bother? */
-#define DTOBASESTR_BUFFER_SIZE 1078
-#define BASEDIGIT(digit) ((char)(((digit) >= 10) ? 'a' - 10 + (digit) : '0' + (digit)))
-
-JS_FRIEND_API(char *)
-JS_dtobasestr(int base, double d)
-{
- char *buffer; /* The output string */
- char *p; /* Pointer to current position in the buffer */
- char *pInt; /* Pointer to the beginning of the integer part of the string */
- char *q;
- uint32 digit;
- double di; /* d truncated to an integer */
- double df; /* The fractional part of d */
-
- JS_ASSERT(base >= 2 && base <= 36);
-
- buffer = (char*) malloc(DTOBASESTR_BUFFER_SIZE);
- if (buffer) {
- p = buffer;
- if (d < 0.0
-#if defined(XP_WIN) || defined(XP_OS2)
- && !((word0(d) & Exp_mask) == Exp_mask && ((word0(d) & Frac_mask) || word1(d))) /* Visual C++ doesn't know how to compare against NaN */
-#endif
- ) {
- *p++ = '-';
- d = -d;
- }
-
- /* Check for Infinity and NaN */
- if ((word0(d) & Exp_mask) == Exp_mask) {
- strcpy(p, !word1(d) && !(word0(d) & Frac_mask) ? "Infinity" : "NaN");
- return buffer;
- }
-
- /* Locking for Balloc's shared buffers */
- ACQUIRE_DTOA_LOCK();
-
- /* Output the integer part of d with the digits in reverse order. */
- pInt = p;
- di = fd_floor(d);
- if (di <= 4294967295.0) {
- uint32 n = (uint32)di;
- if (n)
- do {
- uint32 m = n / base;
- digit = n - m*base;
- n = m;
- JS_ASSERT(digit < (uint32)base);
- *p++ = BASEDIGIT(digit);
- } while (n);
- else *p++ = '0';
- } else {
- int32 e;
- int32 bits; /* Number of significant bits in di; not used. */
- Bigint *b = d2b(di, &e, &bits);
- if (!b)
- goto nomem1;
- b = lshift(b, e);
- if (!b) {
- nomem1:
- Bfree(b);
- return NULL;
- }
- do {
- digit = divrem(b, base);
- JS_ASSERT(digit < (uint32)base);
- *p++ = BASEDIGIT(digit);
- } while (b->wds);
- Bfree(b);
- }
- /* Reverse the digits of the integer part of d. */
- q = p-1;
- while (q > pInt) {
- char ch = *pInt;
- *pInt++ = *q;
- *q-- = ch;
- }
-
- df = d - di;
- if (df != 0.0) {
- /* We have a fraction. */
- int32 e, bbits, s2, done;
- Bigint *b, *s, *mlo, *mhi;
-
- b = s = mlo = mhi = NULL;
-
- *p++ = '.';
- b = d2b(df, &e, &bbits);
- if (!b) {
- nomem2:
- Bfree(b);
- Bfree(s);
- if (mlo != mhi)
- Bfree(mlo);
- Bfree(mhi);
- return NULL;
- }
- JS_ASSERT(e < 0);
- /* At this point df = b * 2^e. e must be less than zero because 0 < df < 1. */
-
- s2 = -(int32)(word0(d) >> Exp_shift1 & Exp_mask>>Exp_shift1);
-#ifndef Sudden_Underflow
- if (!s2)
- s2 = -1;
-#endif
- s2 += Bias + P;
- /* 1/2^s2 = (nextDouble(d) - d)/2 */
- JS_ASSERT(-s2 < e);
- mlo = i2b(1);
- if (!mlo)
- goto nomem2;
- mhi = mlo;
- if (!word1(d) && !(word0(d) & Bndry_mask)
-#ifndef Sudden_Underflow
- && word0(d) & (Exp_mask & Exp_mask << 1)
-#endif
- ) {
- /* The special case. Here we want to be within a quarter of the last input
- significant digit instead of one half of it when the output string's value is less than d. */
- s2 += Log2P;
- mhi = i2b(1<<Log2P);
- if (!mhi)
- goto nomem2;
- }
- b = lshift(b, e + s2);
- if (!b)
- goto nomem2;
- s = i2b(1);
- if (!s)
- goto nomem2;
- s = lshift(s, s2);
- if (!s)
- goto nomem2;
- /* At this point we have the following:
- * s = 2^s2;
- * 1 > df = b/2^s2 > 0;
- * (d - prevDouble(d))/2 = mlo/2^s2;
- * (nextDouble(d) - d)/2 = mhi/2^s2. */
-
- done = JS_FALSE;
- do {
- int32 j, j1;
- Bigint *delta;
-
- b = multadd(b, base, 0);
- if (!b)
- goto nomem2;
- digit = quorem2(b, s2);
- if (mlo == mhi) {
- mlo = mhi = multadd(mlo, base, 0);
- if (!mhi)
- goto nomem2;
- }
- else {
- mlo = multadd(mlo, base, 0);
- if (!mlo)
- goto nomem2;
- mhi = multadd(mhi, base, 0);
- if (!mhi)
- goto nomem2;
- }
-
- /* Do we yet have the shortest string that will round to d? */
- j = cmp(b, mlo);
- /* j is b/2^s2 compared with mlo/2^s2. */
- delta = diff(s, mhi);
- if (!delta)
- goto nomem2;
- j1 = delta->sign ? 1 : cmp(b, delta);
- Bfree(delta);
- /* j1 is b/2^s2 compared with 1 - mhi/2^s2. */
-
-#ifndef ROUND_BIASED
- if (j1 == 0 && !(word1(d) & 1)) {
- if (j > 0)
- digit++;
- done = JS_TRUE;
- } else
-#endif
- if (j < 0 || (j == 0
-#ifndef ROUND_BIASED
- && !(word1(d) & 1)
-#endif
- )) {
- if (j1 > 0) {
- /* Either dig or dig+1 would work here as the least significant digit.
- Use whichever would produce an output value closer to d. */
- b = lshift(b, 1);
- if (!b)
- goto nomem2;
- j1 = cmp(b, s);
- if (j1 > 0) /* The even test (|| (j1 == 0 && (digit & 1))) is not here because it messes up odd base output
- * such as 3.5 in base 3. */
- digit++;
- }
- done = JS_TRUE;
- } else if (j1 > 0) {
- digit++;
- done = JS_TRUE;
- }
- JS_ASSERT(digit < (uint32)base);
- *p++ = BASEDIGIT(digit);
- } while (!done);
- Bfree(b);
- Bfree(s);
- if (mlo != mhi)
- Bfree(mlo);
- Bfree(mhi);
- }
- JS_ASSERT(p < buffer + DTOBASESTR_BUFFER_SIZE);
- *p = '\0';
- RELEASE_DTOA_LOCK();
- }
- return buffer;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2026-07-24 07:15:42 +0000