diff options
author | mmitchel <mmitchel@138bc75d-0d04-0410-961f-82ee72b054a4> | 2001-02-05 11:01:36 +0000 |
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committer | mmitchel <mmitchel@138bc75d-0d04-0410-961f-82ee72b054a4> | 2001-02-05 11:01:36 +0000 |
commit | 815d1ce772900c3969ee09db6d4c52c3248664b1 (patch) | |
tree | 7d2c2f4379041aeae8b380308e1294d0a49ff67a /libio/floatconv.c | |
parent | 4f96fb1842153f431aa064c110b3684e579f1faa (diff) | |
download | gcc-815d1ce772900c3969ee09db6d4c52c3248664b1.tar.gz |
Remove libio
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@39453 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libio/floatconv.c')
-rw-r--r-- | libio/floatconv.c | 2375 |
1 files changed, 0 insertions, 2375 deletions
diff --git a/libio/floatconv.c b/libio/floatconv.c deleted file mode 100644 index 9503187b5d5..00000000000 --- a/libio/floatconv.c +++ /dev/null @@ -1,2375 +0,0 @@ -/* -Copyright (C) 1993, 1994 Free Software Foundation - -This file is part of the GNU IO Library. This library is free -software; you can redistribute it and/or modify it under the -terms of the GNU General Public License as published by the -Free Software Foundation; either version 2, or (at your option) -any later version. - -This library is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with this library; see the file COPYING. If not, write to the Free -Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - -As a special exception, if you link this library with files -compiled with a GNU compiler to produce an executable, this does not cause -the resulting executable to be covered by the GNU General Public License. -This exception does not however invalidate any other reasons why -the executable file might be covered by the GNU General Public License. */ - -#include <libioP.h> -#ifdef _IO_USE_DTOA -/**************************************************************** - * - * The author of this software is David M. Gay. - * - * Copyright (c) 1991 by AT&T. - * - * 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 AT&T MAKES ANY - * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY - * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. - * - ***************************************************************/ - -/* Some cleaning up by Per Bothner, bothner@cygnus.com, 1992, 1993. - Re-written to not need static variables - (except result, result_k, HIWORD, LOWORD). */ - -/* Note that the checking of _DOUBLE_IS_32BITS is for use with the - cross targets that employ the newlib ieeefp.h header. -- brendan */ - -/* Please send bug reports to - David M. Gay - AT&T Bell Laboratories, Room 2C-463 - 600 Mountain Avenue - Murray Hill, NJ 07974-2070 - U.S.A. - dmg@research.att.com or research!dmg - */ - -/* strtod for IEEE-, VAX-, and IBM-arithmetic machines. - * - * This strtod returns a nearest machine number to the input decimal - * string (or sets errno to ERANGE). 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, IBM, or VAX 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 Sudden_Underflow for IEEE-format machines without gradual - * underflow (i.e., that flush to zero on underflow). - * #define IBM for IBM mainframe-style floating-point arithmetic. - * #define VAX for VAX-style floating-point arithmetic. - * #define Unsigned_Shifts if >> does treats its left operand as unsigned. - * #define No_leftright to omit left-right logic in fast floating-point - * computation of 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 KR_headers for old-style C function headers. - */ - -#ifdef DEBUG -#include <stdio.h> -#define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);} -#endif - -#ifdef __STDC__ -#include <stdlib.h> -#include <string.h> -#include <float.h> -#define CONST const -#else -#define CONST -#define KR_headers - -/* In this case, we assume IEEE floats. */ -#define FLT_ROUNDS 1 -#define FLT_RADIX 2 -#define DBL_MANT_DIG 53 -#define DBL_DIG 15 -#define DBL_MAX_10_EXP 308 -#define DBL_MAX_EXP 1024 -#endif - -#include <errno.h> -#ifndef __MATH_H__ -#include <math.h> -#endif - -#ifdef Unsigned_Shifts -#define Sign_Extend(a,b) if (b < 0) a |= 0xffff0000; -#else -#define Sign_Extend(a,b) /*no-op*/ -#endif - -#if defined(__i386__) || defined(__i860__) || defined(clipper) -#define IEEE_8087 -#endif -#if defined(MIPSEL) || defined(__alpha__) -#define IEEE_8087 -#endif -#if defined(__sparc__) || defined(sparc) || defined(MIPSEB) -#define IEEE_MC68k -#endif - -#if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1 - -#ifndef _DOUBLE_IS_32BITS -#if FLT_RADIX==16 -#define IBM -#else -#if DBL_MANT_DIG==56 -#define VAX -#else -#if DBL_MANT_DIG==53 && DBL_MAX_10_EXP==308 -#define IEEE_Unknown -#else -Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined. -#endif -#endif -#endif -#endif /* !_DOUBLE_IS_32BITS */ -#endif - -typedef _G_uint32_t unsigned32; - -union doubleword { - double d; - unsigned32 u[2]; -}; - -#ifdef IEEE_8087 -#define HIWORD 1 -#define LOWORD 0 -#define TEST_ENDIANNESS /* nothing */ -#else -#if defined(IEEE_MC68k) -#define HIWORD 0 -#define LOWORD 1 -#define TEST_ENDIANNESS /* nothing */ -#else -static int HIWORD = -1, LOWORD; -static void test_endianness() -{ - union doubleword dw; - dw.d = 10; - if (dw.u[0] != 0) /* big-endian */ - HIWORD=0, LOWORD=1; - else - HIWORD=1, LOWORD=0; -} -#define TEST_ENDIANNESS if (HIWORD<0) test_endianness(); -#endif -#endif - -#if 0 -union doubleword _temp; -#endif -#if defined(__GNUC__) && !defined(_DOUBLE_IS_32BITS) -#define word0(x) ({ union doubleword _du; _du.d = (x); _du.u[HIWORD]; }) -#define word1(x) ({ union doubleword _du; _du.d = (x); _du.u[LOWORD]; }) -#define setword0(D,W) \ - ({ union doubleword _du; _du.d = (D); _du.u[HIWORD]=(W); (D)=_du.d; }) -#define setword1(D,W) \ - ({ union doubleword _du; _du.d = (D); _du.u[LOWORD]=(W); (D)=_du.d; }) -#define setwords(D,W0,W1) ({ union doubleword _du; \ - _du.u[HIWORD]=(W0); _du.u[LOWORD]=(W1); (D)=_du.d; }) -#define addword0(D,W) \ - ({ union doubleword _du; _du.d = (D); _du.u[HIWORD]+=(W); (D)=_du.d; }) -#else -#define word0(x) ((unsigned32 *)&x)[HIWORD] -#ifndef _DOUBLE_IS_32BITS -#define word1(x) ((unsigned32 *)&x)[LOWORD] -#else -#define word1(x) 0 -#endif -#define setword0(D,W) word0(D) = (W) -#ifndef _DOUBLE_IS_32BITS -#define setword1(D,W) word1(D) = (W) -#define setwords(D,W0,W1) (setword0(D,W0),setword1(D,W1)) -#else -#define setword1(D,W) -#define setwords(D,W0,W1) (setword0(D,W0)) -#endif -#define addword0(D,X) (word0(D) += (X)) -#endif - -/* The following definition of Storeinc is appropriate for MIPS processors. */ -#if defined(IEEE_8087) + defined(VAX) -#define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \ -((unsigned short *)a)[0] = (unsigned short)c, a++) -#else -#if defined(IEEE_MC68k) -#define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \ -((unsigned short *)a)[1] = (unsigned short)c, a++) -#else -#define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff) -#endif -#endif - -/* #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) */ - -#if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(IEEE_Unknown) -#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 IEEE_Arith -#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 */ -#else -#undef Sudden_Underflow -#define Sudden_Underflow -#ifdef IBM -#define Exp_shift 24 -#define Exp_shift1 24 -#define Exp_msk1 0x1000000 -#define Exp_msk11 0x1000000 -#define Exp_mask 0x7f000000 -#define P 14 -#define Bias 65 -#define Exp_1 0x41000000 -#define Exp_11 0x41000000 -#define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */ -#define Frac_mask 0xffffff -#define Frac_mask1 0xffffff -#define Bletch 4 -#define Ten_pmax 22 -#define Bndry_mask 0xefffff -#define Bndry_mask1 0xffffff -#define LSB 1 -#define Sign_bit 0x80000000 -#define Log2P 4 -#define Tiny0 0x100000 -#define Tiny1 0 -#define Quick_max 14 -#define Int_max 15 -#else /* VAX */ -#define Exp_shift 23 -#define Exp_shift1 7 -#define Exp_msk1 0x80 -#define Exp_msk11 0x800000 -#define Exp_mask 0x7f80 -#define P 56 -#define Bias 129 -#define Exp_1 0x40800000 -#define Exp_11 0x4080 -#define Ebits 8 -#define Frac_mask 0x7fffff -#define Frac_mask1 0xffff007f -#define Ten_pmax 24 -#define Bletch 2 -#define Bndry_mask 0xffff007f -#define Bndry_mask1 0xffff007f -#define LSB 0x10000 -#define Sign_bit 0x8000 -#define Log2P 1 -#define Tiny0 0x80 -#define Tiny1 0 -#define Quick_max 15 -#define Int_max 15 -#endif -#endif - -#ifndef IEEE_Arith -#define ROUND_BIASED -#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 - -#define Kmax 15 - -/* (1<<BIGINT_MINIMUM_K) is the minimum number of words to allocate - in a Bigint. dtoa usually manages with 1<<2, and has not been - known to need more than 1<<3. */ - -#define BIGINT_MINIMUM_K 3 - -struct Bigint { - struct Bigint *next; - int k; /* Parameter given to Balloc(k) */ - int maxwds; /* Allocated space: equals 1<<k. */ - short on_stack; /* 1 if stack-allocated. */ - short sign; /* 0 if value is positive or zero; 1 if negative. */ - int wds; /* Current length. */ - unsigned32 x[1<<BIGINT_MINIMUM_K]; /* Actually: x[maxwds] */ -}; - -#define BIGINT_HEADER_SIZE \ - (sizeof(Bigint) - (1<<BIGINT_MINIMUM_K) * sizeof(unsigned32)) - -typedef struct Bigint Bigint; - -/* Initialize a stack-allocated Bigint. */ - -static Bigint * -Binit -#ifdef KR_headers - (v) Bigint *v; -#else - (Bigint *v) -#endif -{ - v->on_stack = 1; - v->k = BIGINT_MINIMUM_K; - v->maxwds = 1 << BIGINT_MINIMUM_K; - v->sign = v->wds = 0; - return v; -} - -/* Allocate a Bigint with '1<<k' big digits. */ - -static Bigint * -Balloc -#ifdef KR_headers - (k) int k; -#else - (int k) -#endif -{ - int x; - Bigint *rv; - - if (k < BIGINT_MINIMUM_K) - k = BIGINT_MINIMUM_K; - - x = 1 << k; - rv = (Bigint *) - malloc(BIGINT_HEADER_SIZE + x * sizeof(unsigned32)); - rv->k = k; - rv->maxwds = x; - rv->sign = rv->wds = 0; - rv->on_stack = 0; - return rv; -} - -static void -Bfree -#ifdef KR_headers - (v) Bigint *v; -#else - (Bigint *v) -#endif -{ - if (v && !v->on_stack) - free (v); -} - -static void -Bcopy -#ifdef KR_headers - (x, y) Bigint *x, *y; -#else - (Bigint *x, Bigint *y) -#endif -{ - register unsigned32 *xp, *yp; - register int i = y->wds; - x->sign = y->sign; - x->wds = i; - for (xp = x->x, yp = y->x; --i >= 0; ) - *xp++ = *yp++; -} - -/* Make sure b has room for at least 1<<k big digits. */ - -static Bigint * -Brealloc -#ifdef KR_headers - (b, k) Bigint *b; int k; -#else - (Bigint * b, int k) -#endif -{ - if (b == NULL) - return Balloc(k); - if (b->k >= k) - return b; - else - { - Bigint *rv = Balloc (k); - Bcopy(rv, b); - Bfree(b); - return rv; - } -} - -/* Return b*m+a. b is modified. - Assumption: 0xFFFF*m+a fits in 32 bits. */ - -static Bigint * -multadd -#ifdef KR_headers - (b, m, a) Bigint *b; int m, a; -#else - (Bigint *b, int m, int a) -#endif -{ - int i, wds; - unsigned32 *x, y; - unsigned32 xi, z; - - wds = b->wds; - x = b->x; - i = 0; - do { - xi = *x; - y = (xi & 0xffff) * m + a; - z = (xi >> 16) * m + (y >> 16); - a = (int)(z >> 16); - *x++ = (z << 16) + (y & 0xffff); - } - while(++i < wds); - if (a) { - if (wds >= b->maxwds) - b = Brealloc(b, b->k+1); - b->x[wds++] = a; - b->wds = wds; - } - return b; - } - -static Bigint * -s2b -#ifdef KR_headers - (result, s, nd0, nd, y9) - Bigint *result; CONST char *s; int nd0, nd; unsigned32 y9; -#else - (Bigint *result, CONST char *s, int nd0, int nd, unsigned32 y9) -#endif -{ - int i, k; - _G_int32_t x, y; - - x = (nd + 8) / 9; - for(k = 0, y = 1; x > y; y <<= 1, k++) ; - result = Brealloc(result, k); - result->x[0] = y9; - result->wds = 1; - - i = 9; - if (9 < nd0) - { - s += 9; - do - result = multadd(result, 10, *s++ - '0'); - while (++i < nd0); - s++; - } - else - s += 10; - for(; i < nd; i++) - result = multadd(result, 10, *s++ - '0'); - return result; -} - -static int -hi0bits -#ifdef KR_headers - (x) register unsigned32 x; -#else - (register unsigned32 x) -#endif -{ - register int 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; - } - -static int -lo0bits -#ifdef KR_headers - (y) unsigned32 *y; -#else - (unsigned32 *y) -#endif -{ - register int k; - register unsigned32 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; - } - -static Bigint * -i2b -#ifdef KR_headers - (result, i) Bigint *result; int i; -#else - (Bigint* result, int i) -#endif -{ - result = Brealloc(result, 1); - result->x[0] = i; - result->wds = 1; - return result; -} - -/* Do: c = a * b. */ - -static Bigint * -mult -#ifdef KR_headers - (c, a, b) Bigint *a, *b, *c; -#else - (Bigint *c, Bigint *a, Bigint *b) -#endif -{ - int k, wa, wb, wc; - unsigned32 carry, y, z; - unsigned32 *x, *xa, *xae, *xb, *xbe, *xc, *xc0; - unsigned32 z2; - if (a->wds < b->wds) { - Bigint *tmp = a; - a = b; - b = tmp; - } - k = a->k; - wa = a->wds; - wb = b->wds; - wc = wa + wb; - if (wc > a->maxwds) - k++; - c = Brealloc(c, k); - for(x = c->x, xa = x + wc; x < xa; x++) - *x = 0; - xa = a->x; - xae = xa + wa; - xb = b->x; - xbe = xb + wb; - xc0 = c->x; - for(; xb < xbe; xb++, xc0++) { - if ((y = *xb & 0xffff)) { - 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)) { - 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; - } - } - for(xc0 = c->x, xc = xc0 + wc; wc > 0 && !*--xc; --wc) ; - c->wds = wc; - return c; - } - -/* Returns b*(5**k). b is modified. */ -/* Re-written by Per Bothner to not need a static list. */ - -static Bigint * -pow5mult -#ifdef KR_headers - (b, k) Bigint *b; int k; -#else - (Bigint *b, int k) -#endif -{ - static int p05[6] = { 5, 25, 125, 625, 3125, 15625 }; - - for (; k > 6; k -= 6) - b = multadd(b, 15625, 0); /* b *= 5**6 */ - if (k == 0) - return b; - else - return multadd(b, p05[k-1], 0); -} - -/* Re-written by Per Bothner so shift can be in place. */ - -static Bigint * -lshift -#ifdef KR_headers - (b, k) Bigint *b; int k; -#else - (Bigint *b, int k) -#endif -{ - int i; - unsigned32 *x, *x1, *xe; - int old_wds = b->wds; - int n = k >> 5; - int k1 = b->k; - int n1 = n + old_wds + 1; - - if (k == 0) - return b; - - for(i = b->maxwds; n1 > i; i <<= 1) - k1++; - b = Brealloc(b, k1); - - xe = b->x; /* Source limit */ - x = xe + old_wds; /* Source pointer */ - x1 = x + n; /* Destination pointer */ - if (k &= 0x1f) { - int k1 = 32 - k; - unsigned32 z = *--x; - if ((*x1 = (z >> k1)) != 0) { - ++n1; - } - while (x > xe) { - unsigned32 w = *--x; - *--x1 = (z << k) | (w >> k1); - z = w; - } - *--x1 = z << k; - } - else - do { - *--x1 = *--x; - } while(x > xe); - while (x1 > xe) - *--x1 = 0; - b->wds = n1 - 1; - return b; -} - -static int -cmp -#ifdef KR_headers - (a, b) Bigint *a, *b; -#else - (Bigint *a, Bigint *b) -#endif -{ - unsigned32 *xa, *xa0, *xb, *xb0; - int 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; - } - -/* Do: c = a-b. */ - -static Bigint * -diff -#ifdef KR_headers - (c, a, b) Bigint *c, *a, *b; -#else - (Bigint *c, Bigint *a, Bigint *b) -#endif -{ - int i, wa, wb; - _G_int32_t borrow, y; /* We need signed shifts here. */ - unsigned32 *xa, *xae, *xb, *xbe, *xc; - _G_int32_t z; - - i = cmp(a,b); - if (!i) { - c = Brealloc(c, 0); - c->wds = 1; - c->x[0] = 0; - return c; - } - if (i < 0) { - Bigint *tmp = a; - a = b; - b = tmp; - i = 1; - } - else - i = 0; - c = Brealloc(c, a->k); - 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; - do { - y = (*xa & 0xffff) - (*xb & 0xffff) + borrow; - borrow = y >> 16; - Sign_Extend(borrow, y); - z = (*xa++ >> 16) - (*xb++ >> 16) + borrow; - borrow = z >> 16; - Sign_Extend(borrow, z); - Storeinc(xc, z, y); - } - while(xb < xbe); - while(xa < xae) { - y = (*xa & 0xffff) + borrow; - borrow = y >> 16; - Sign_Extend(borrow, y); - z = (*xa++ >> 16) + borrow; - borrow = z >> 16; - Sign_Extend(borrow, z); - Storeinc(xc, z, y); - } - while(!*--xc) - wa--; - c->wds = wa; - return c; - } - -static double -ulp -#ifdef KR_headers - (x) double x; -#else - (double x) -#endif -{ - register _G_int32_t L; - double a; - - L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1; -#ifndef Sudden_Underflow - if (L > 0) { -#endif -#ifdef IBM - L |= Exp_msk1 >> 4; -#endif - setwords(a, L, 0); -#ifndef Sudden_Underflow - } - else { - L = -L >> Exp_shift; - if (L < Exp_shift) - setwords(a, 0x80000 >> L, 0); - else { - L -= Exp_shift; - setwords(a, 0, L >= 31 ? 1 : 1 << (31 - L)); - } - } -#endif - return a; - } - -static double -b2d -#ifdef KR_headers - (a, e) Bigint *a; int *e; -#else - (Bigint *a, int *e) -#endif -{ - unsigned32 *xa, *xa0, w, y, z; - int k; - double d; - unsigned32 d0, d1; - - 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) { - d0 = Exp_1 | y >> (Ebits - k); - w = xa > xa0 ? *--xa : 0; -#ifndef _DOUBLE_IS_32BITS - d1 = y << ((32-Ebits) + k) | w >> (Ebits - k); -#endif - goto ret_d; - } - z = xa > xa0 ? *--xa : 0; - if (k -= Ebits) { - d0 = Exp_1 | y << k | z >> (32 - k); - y = xa > xa0 ? *--xa : 0; -#ifndef _DOUBLE_IS_32BITS - d1 = z << k | y >> (32 - k); -#endif - } - else { - d0 = Exp_1 | y; -#ifndef _DOUBLE_IS_32BITS - d1 = z; -#endif - } - ret_d: -#ifdef VAX - setwords(d, d0 >> 16 | d0 << 16, d1 >> 16 | d1 << 16); -#else - setwords (d, d0, d1); -#endif - return d; - } - -static Bigint * -d2b -#ifdef KR_headers - (result, d, e, bits) Bigint *result; double d; _G_int32_t *e, *bits; -#else - (Bigint *result, double d, _G_int32_t *e, _G_int32_t *bits) -#endif -{ - int de, i, k; - unsigned32 *x, y, z; - unsigned32 d0, d1; -#ifdef VAX - d0 = word0(d) >> 16 | word0(d) << 16; - d1 = word1(d) >> 16 | word1(d) << 16; -#else - d0 = word0(d); - d1 = word1(d); -#endif - - result = Brealloc(result, 1); - x = result->x; - - z = d0 & Frac_mask; - d0 &= 0x7fffffff; /* clear sign bit, which we ignore */ - - de = (int)(d0 >> Exp_shift); /* The exponent part of d. */ - - /* Put back the suppressed high-order bit, if normalized. */ -#ifndef IBM -#ifndef Sudden_Underflow - if (de) -#endif - z |= Exp_msk11; -#endif - -#ifndef _DOUBLE_IS_32BITS - if ((y = d1)) { - if ((k = lo0bits(&y))) { - x[0] = y | z << (32 - k); - z >>= k; - } - else - x[0] = y; - i = result->wds = (x[1] = z) ? 2 : 1; - } - else { -#endif /* !_DOUBLE_IS_32BITS */ -#ifdef DEBUG - if (!z) - Bug("Zero passed to d2b"); -#endif - k = lo0bits(&z); - x[0] = z; - i = result->wds = 1; -#ifndef _DOUBLE_IS_32BITS - k += 32; - } -#endif -#ifndef Sudden_Underflow - if (de) { -#endif -#ifdef IBM - *e = (de - Bias - (P-1) << 2) + k; - *bits = 4*P + 8 - k - hi0bits(word0(d) & Frac_mask); -#else - *e = de - Bias - (P-1) + k; - *bits = P - k; -#endif -#ifndef Sudden_Underflow - } - else { - *e = de - Bias - (P-1) + 1 + k; - *bits = 32*i - hi0bits(x[i-1]); - } -#endif - return result; - } - -static double -ratio -#ifdef KR_headers - (a, b) Bigint *a, *b; -#else - (Bigint *a, Bigint *b) -#endif -{ - double da, db; - int k, ka, kb; - - da = b2d(a, &ka); - db = b2d(b, &kb); - k = ka - kb + 32*(a->wds - b->wds); -#ifdef IBM - if (k > 0) { - addword0(da, (k >> 2)*Exp_msk1); - if (k &= 3) - da *= 1 << k; - } - else { - k = -k; - addword0(db,(k >> 2)*Exp_msk1); - if (k &= 3) - db *= 1 << k; - } -#else - if (k > 0) - addword0(da, k*Exp_msk1); - else { - k = -k; - addword0(db, k*Exp_msk1); - } -#endif - 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 -#ifdef VAX - , 1e23, 1e24 -#endif - }; - -#ifdef IEEE_Arith -static CONST double bigtens[] = { 1e16, 1e32, 1e64, 1e128, 1e256 }; -static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128, 1e-256 }; -#define n_bigtens 5 -#else -#ifdef IBM -static CONST double bigtens[] = { 1e16, 1e32, 1e64 }; -static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64 }; -#define n_bigtens 3 -#else -/* Also used for the case when !_DOUBLE_IS_32BITS. */ -static CONST double bigtens[] = { 1e16, 1e32 }; -static CONST double tinytens[] = { 1e-16, 1e-32 }; -#define n_bigtens 2 -#endif -#endif - - double -_IO_strtod -#ifdef KR_headers - (s00, se) CONST char *s00; char **se; -#else - (CONST char *s00, char **se) -#endif -{ - _G_int32_t 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; - _G_int32_t L; - unsigned32 y, z; - Bigint _bb, _b_avail, _bd, _bd0, _bs, _delta; - Bigint *bb = Binit(&_bb); - Bigint *bd = Binit(&_bd); - Bigint *bd0 = Binit(&_bd0); - Bigint *bs = Binit(&_bs); - Bigint *b_avail = Binit(&_b_avail); - Bigint *delta = Binit(&_delta); - - TEST_ENDIANNESS; - sign = nz0 = nz = 0; - rv = 0.; - (void)&rv; /* Force rv into the stack */ - for(s = s00;;s++) switch(*s) { - case '-': - sign = 1; - /* no break */ - case '+': - if (*++s) - goto break2; - /* no break */ - case 0: - /* "+" and "-" should be reported as an error? */ - sign = 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') { - e = c - '0'; - s1 = s; - while((c = *++s) >= '0' && c <= '9') - e = 10*e + c - '0'; - if (s - s1 > 8) - /* Avoid confusion from exponents - * so large that e might overflow. - */ - e = 9999999; - if (esign) - e = -e; - } - else - e = 0; - } - else - s = s00; - } - if (!nd) { - if (!nz && !nz0) - 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; - if (nd <= DBL_DIG -#ifndef RND_PRODQUOT - && FLT_ROUNDS == 1 -#endif - ) { - if (!e) - goto ret; - if (e > 0) { - if (e <= Ten_pmax) { -#ifdef VAX - goto vax_ovfl_check; -#else - /* rv = */ rounded_product(rv, tens[e]); - goto ret; -#endif - } - 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]; -#ifdef VAX - /* VAX exponent range is so narrow we must - * worry about overflow here... - */ - vax_ovfl_check: - addword0(rv, - P*Exp_msk1); - /* rv = */ rounded_product(rv, tens[e]); - if ((word0(rv) & Exp_mask) - > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) - goto ovfl; - addword0(rv, P*Exp_msk1); -#else - /* rv = */ rounded_product(rv, tens[e]); -#endif - goto ret; - } - } -#ifndef Inaccurate_Divide - else if (e >= -Ten_pmax) { - /* rv = */ rounded_quotient(rv, tens[-e]); - goto ret; - } -#endif - } - e1 += nd - k; - - /* Get starting approximation = rv * 10**e1 */ - - if (e1 > 0) { - if ((i = e1 & 15)) - rv *= tens[i]; - if (e1 &= ~15) { - if (e1 > DBL_MAX_10_EXP) { - ovfl: - errno = ERANGE; -#if defined(sun) && !defined(__svr4__) -/* SunOS defines HUGE_VAL as __infinity(), which is in libm. */ -#undef HUGE_VAL -#endif -#ifndef HUGE_VAL -#define HUGE_VAL 1.7976931348623157E+308 -#endif - rv = HUGE_VAL; - goto ret; - } - if (e1 >>= 4) { - for(j = 0; e1 > 1; j++, e1 >>= 1) - if (e1 & 1) - rv *= bigtens[j]; - /* The last multiplication could overflow. */ - addword0(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) */ - setwords(rv, Big0, Big1); - } - else - addword0(rv, P*Exp_msk1); - } - - } - } - else if (e1 < 0) { - e1 = -e1; - if ((i = e1 & 15)) - rv /= tens[i]; - if (e1 &= ~15) { - e1 >>= 4; - 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]; - if (!rv) { - undfl: - rv = 0.; - errno = ERANGE; - goto ret; - } - setwords(rv, Tiny0, Tiny1); - /* The refinement below will clean - * this approximation up. - */ - } - } - } - - /* Now the hard part -- adjusting rv to the correct value.*/ - - /* Put digits into bd: true value = bd * 10^e */ - - bd0 = s2b(bd0, s0, nd0, nd, y); - bd = Brealloc(bd, bd0->k); - - for(;;) { - Bcopy(bd, bd0); - bb = d2b(bb, rv, &bbe, &bbbits); /* rv = bb * 2^bbe */ - bs = i2b(bs, 1); - - 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 -#ifdef IBM - j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3); -#else - j = P + 1 - bbbits; -#endif -#else - i = bbe + bbbits - 1; /* logb(rv) */ - if (i < Emin) /* denormal */ - j = bbe + (P-Emin); - else - j = P + 1 - bbbits; -#endif - bb2 += j; - bd2 += j; - i = bb2 < bd2 ? bb2 : bd2; - if (i > bs2) - i = bs2; - if (i > 0) { - bb2 -= i; - bd2 -= i; - bs2 -= i; - } - if (bb5 > 0) { - Bigint *b_tmp; - bs = pow5mult(bs, bb5); - b_tmp = mult(b_avail, bs, bb); - b_avail = bb; - bb = b_tmp; - } - if (bb2 > 0) - bb = lshift(bb, bb2); - if (bd5 > 0) - bd = pow5mult(bd, bd5); - if (bd2 > 0) - bd = lshift(bd, bd2); - if (bs2 > 0) - bs = lshift(bs, bs2); - delta = diff(delta, bb, bd); - 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) - break; - delta = lshift(delta,Log2P); - 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*/ - setword0(rv, (word0(rv) & Exp_mask) - + Exp_msk1); -#ifdef IBM - setword0 (rv, - word0(rv) | (Exp_msk1 >> 4)); -#endif - setword1(rv, 0); - break; - } - } - else if (!(word0(rv) & Bndry_mask) && !word1(rv)) { - drop_down: - /* boundary case -- decrement exponent */ -#ifdef Sudden_Underflow - L = word0(rv) & Exp_mask; -#ifdef IBM - if (L < Exp_msk1) -#else - if (L <= Exp_msk1) -#endif - goto undfl; - L -= Exp_msk1; -#else - L = (word0(rv) & Exp_mask) - Exp_msk1; -#endif - setwords(rv, L | Bndry_mask1, 0xffffffff); -#ifdef IBM - continue; -#else - break; -#endif - } -#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 - } -#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; - addword0(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; - setwords(rv, Big0, Big1); - continue; - } - else - addword0(rv, P*Exp_msk1); - } - else { -#ifdef Sudden_Underflow - if ((word0(rv) & Exp_mask) <= P*Exp_msk1) { - rv0 = rv; - addword0(rv, P*Exp_msk1); - adj = aadj1 * ulp(rv); - rv += adj; -#ifdef IBM - if ((word0(rv) & Exp_mask) < P*Exp_msk1) -#else - if ((word0(rv) & Exp_mask) <= P*Exp_msk1) -#endif - { - if (word0(rv0) == Tiny0 - && word1(rv0) == Tiny1) - goto undfl; - setwords(rv, Tiny0, Tiny1); - continue; - } - else - addword0(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 . - */ - if (y <= (P-1)*Exp_msk1 && aadj >= 1.) { - aadj1 = (double)(int)(aadj + 0.5); - if (!dsign) - aadj1 = -aadj1; - } - adj = aadj1 * ulp(rv); - rv += adj; -#endif - } - z = word0(rv) & Exp_mask; - if (y == z) { - /* Can we stop now? */ - L = (_G_int32_t)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; - } - } - Bfree(bb); - Bfree(bd); - Bfree(bs); - Bfree(bd0); - Bfree(delta); - Bfree(b_avail); - ret: - if (se) - *se = (char *)s; - return sign ? -rv : rv; - } - -static int -quorem -#ifdef KR_headers - (b, S) Bigint *b, *S; -#else - (Bigint *b, Bigint *S) -#endif -{ - int n; - _G_int32_t borrow, y; - unsigned32 carry, q, ys; - unsigned32 *bx, *bxe, *sx, *sxe; - _G_int32_t z; - unsigned32 si, zs; - - n = S->wds; -#ifdef DEBUG - /*debug*/ if (b->wds > n) - /*debug*/ Bug("oversize b in quorem"); -#endif - if (b->wds < n) - return 0; - sx = S->x; - sxe = sx + --n; - bx = b->x; - bxe = bx + n; - q = *bxe / (*sxe + 1); /* ensure q <= true quotient */ -#ifdef DEBUG - /*debug*/ if (q > 9) - /*debug*/ Bug("oversized quotient in quorem"); -#endif - if (q) { - borrow = 0; - carry = 0; - do { - si = *sx++; - ys = (si & 0xffff) * q + carry; - zs = (si >> 16) * q + (ys >> 16); - carry = zs >> 16; - y = (*bx & 0xffff) - (ys & 0xffff) + borrow; - borrow = y >> 16; - Sign_Extend(borrow, y); - z = (*bx >> 16) - (zs & 0xffff) + borrow; - borrow = z >> 16; - Sign_Extend(borrow, z); - Storeinc(bx, z, y); - } - 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 { - si = *sx++; - ys = (si & 0xffff) + carry; - zs = (si >> 16) + (ys >> 16); - carry = zs >> 16; - y = (*bx & 0xffff) - (ys & 0xffff) + borrow; - borrow = y >> 16; - Sign_Extend(borrow, y); - z = (*bx >> 16) - (zs & 0xffff) + borrow; - borrow = z >> 16; - Sign_Extend(borrow, z); - Storeinc(bx, z, y); - } - while(sx <= sxe); - bx = b->x; - bxe = bx + n; - if (!*bxe) { - while(--bxe > bx && !*bxe) - --n; - b->wds = n; - } - } - return 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. - */ - - char * -_IO_dtoa -#ifdef KR_headers - (d, mode, ndigits, decpt, sign, rve) - double d; int mode, ndigits, *decpt, *sign; char **rve; -#else - (double d, int mode, int ndigits, int *decpt, int *sign, char **rve) -#endif -{ - /* 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. - */ - - _G_int32_t 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; - _G_int32_t L; -#ifndef Sudden_Underflow - int denorm; -#endif - Bigint _b_avail, _b, _mhi, _mlo, _S; - Bigint *b_avail = Binit(&_b_avail); - Bigint *b = Binit(&_b); - Bigint *S = Binit(&_S); - /* mhi and mlo are only set and used if leftright. */ - Bigint *mhi = NULL, *mlo = NULL; - double d2, ds, eps; - char *s, *s0; - static Bigint *result = NULL; - static int result_k; - - TEST_ENDIANNESS; - if (result) { - /* result is contains a string, so its fields (interpreted - as a Bigint have been trashed. Restore them. - This is a really ugly interface - result should - not be static, since that is not thread-safe. FIXME. */ - result->k = result_k; - result->maxwds = 1 << result_k; - result->on_stack = 0; - } - - if (word0(d) & Sign_bit) { - /* set sign for everything, including 0's and NaNs */ - *sign = 1; - setword0(d, word0(d) & ~Sign_bit); /* clear sign bit */ - } - else - *sign = 0; - -#if defined(IEEE_Arith) + defined(VAX) -#ifdef IEEE_Arith - if ((word0(d) & Exp_mask) == Exp_mask) -#else - if (word0(d) == 0x8000) -#endif - { - /* Infinity or NaN */ - *decpt = 9999; -#ifdef IEEE_Arith - if (!word1(d) && !(word0(d) & 0xfffff)) - { - s = "Infinity"; - if (rve) - *rve = s + 8; - } - else -#endif - { - s = "NaN"; - if (rve) - *rve = s +3; - } - return s; - } -#endif -#ifdef IBM - d += 0; /* normalize */ -#endif - if (!d) { - *decpt = 1; - s = "0"; - if (rve) - *rve = s + 1; - return s; - } - - b = d2b(b, d, &be, &bbits); - i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1)); -#ifndef Sudden_Underflow - if (i) { -#endif - d2 = d; - setword0(d2, (word0(d2) & Frac_mask1) | Exp_11); -#ifdef IBM - if (j = 11 - hi0bits(word0(d2) & Frac_mask)) - d2 /= 1 << j; -#endif - - i -= Bias; -#ifdef IBM - i <<= 2; - i += j; -#endif -#ifndef Sudden_Underflow - denorm = 0; - } - else { - /* d is denormalized */ - unsigned32 x; - - i = bbits + be + (Bias + (P-1) - 1); - x = i > 32 ? word0(d) << (64 - i) | word1(d) >> (i - 32) - : word1(d) << (32 - i); - d2 = x; - addword0(d2, - 31*Exp_msk1); /* adjust exponent */ - i -= (Bias + (P-1) - 1) + 1; - denorm = 1; - } -#endif - - /* Now i is the unbiased base-2 exponent. */ - - /* 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*log(2)/log(10) + log10(d2) - * - * This suggests computing an approximation k to log10(d) by - * - * k = i*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) by 0.301029995663981; since |i| <= 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.) - */ - - ds = (d2-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981; - k = (int)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; - } - j = bbits - i - 1; - 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; - } - if (mode < 0 || mode > 9) - mode = 0; - try_quick = 1; - if (mode > 5) { - mode -= 4; - try_quick = 0; - } - leftright = 1; - 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; - } - /* i is now an upper bound of the number of digits to generate. */ - j = sizeof(unsigned32) * (1<<BIGINT_MINIMUM_K); - /* The test is <= so as to allow room for the final '\0'. */ - for(result_k = BIGINT_MINIMUM_K; BIGINT_HEADER_SIZE + j <= i; - j <<= 1) result_k++; - if (!result || result_k > result->k) - { - Bfree (result); - result = Balloc(result_k); - } - s = s0 = (char *)result; - - 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 */ - 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)) { - d *= tens[j1 & 0xf]; - for(j = j1 >> 4; j; j >>= 1, i++) - if (j & 1) { - ieps++; - d *= bigtens[i]; - } - } - if (k_check && d < 1. && ilim > 0) { - if (ilim1 <= 0) - goto fast_failed; - ilim = ilim1; - k--; - d *= 10.; - ieps++; - } - eps = ieps*d + 7.; - addword0(eps, - (P-1)*Exp_msk1); - if (ilim == 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 = (_G_int32_t)d; - d -= L; - *s++ = '0' + (int)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 = (_G_int32_t)d; - d -= L; - *s++ = '0' + (int)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 = s0; - 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) { - if (ilim < 0 || d <= 5*ds) - goto no_digits; - goto one_digit; - } - for(i = 1;; i++) { - L = (_G_int32_t)(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' + (int)L; - if (i == ilim) { - d += d; - if (d > ds || (d == ds && L & 1)) { - bump_up: - while(*--s == '9') - if (s == s0) { - 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 -#ifdef IBM - 1 + 4*P - 3 - bbits + ((bbits + be - 1) & 3); -#else - 1 + P - bbits; -#endif - } - 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; - } - } - b2 += i; - s2 += i; - mhi = i2b(Binit(&_mhi), 1); - } - if (m2 > 0 && s2 > 0) { - i = m2 < s2 ? m2 : s2; - b2 -= i; - m2 -= i; - s2 -= i; - } - if (b5 > 0) { - if (leftright) { - if (m5 > 0) { - Bigint *b_tmp; - mhi = pow5mult(mhi, m5); - b_tmp = mult(b_avail, mhi, b); - b_avail = b; - b = b_tmp; - } - if ((j = b5 - m5)) - b = pow5mult(b, j); - } - else - b = pow5mult(b, b5); - } - S = i2b(S, 1); - if (s5 > 0) - S = pow5mult(S, s5); - - /* Check for special case that d is a normalized power of 2. */ - - if (mode < 2) { - if (!word1(d) && !(word0(d) & Bndry_mask) -#ifndef Sudden_Underflow - && word0(d) & Exp_mask -#endif - ) { - /* The special case */ - b2 += Log2P; - s2 += Log2P; - spec_case = 1; - } - else - spec_case = 0; - } - - /* 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)) - i = 32 - i; - if (i > 4) { - i -= 4; - b2 += i; - m2 += i; - s2 += i; - } - else if (i < 4) { - i += 28; - b2 += i; - m2 += i; - s2 += i; - } - if (b2 > 0) - b = lshift(b, b2); - if (s2 > 0) - S = lshift(S, s2); - if (k_check) { - if (cmp(b,S) < 0) { - k--; - b = multadd(b, 10, 0); /* we botched the k estimate */ - if (leftright) - mhi = multadd(mhi, 10, 0); - ilim = ilim1; - } - } - if (ilim <= 0 && mode > 2) { - if (ilim < 0 || cmp(b,S = multadd(S,5,0)) <= 0) { - /* no digits, fcvt style */ - no_digits: - k = -1 - ndigits; - goto ret; - } - one_digit: - *s++ = '1'; - k++; - goto ret; - } - if (leftright) { - if (m2 > 0) - mhi = lshift(mhi, m2); - - /* Compute mlo -- check for special case - * that d is a normalized power of 2. - */ - - if (spec_case) { - mlo = Brealloc(Binit(&_mlo), mhi->k); - Bcopy(mlo, mhi); - mhi = lshift(mhi, Log2P); - } - else - mlo = mhi; - - 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); - b_avail = diff(b_avail, S, mhi); /* b_avail = S - mi */ - j1 = b_avail->sign ? 1 : cmp(b, b_avail); -#ifndef ROUND_BIASED - if (j1 == 0 && !mode && !(word1(d) & 1)) { - if (dig == '9') - goto round_9_up; - if (j > 0) - dig++; - *s++ = dig; - goto ret; - } -#endif - if (j < 0 || (j == 0 && !mode -#ifndef ROUND_BIASED - && !(word1(d) & 1) -#endif - )) { - if (j1 > 0) { - b = lshift(b, 1); - j1 = cmp(b, S); - if ((j1 > 0 || (j1 == 0 && dig & 1)) - && dig++ == '9') - goto round_9_up; - } - *s++ = 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++ = dig; - if (i == ilim) - break; - b = multadd(b, 10, 0); - if (mlo == mhi) - mlo = mhi = multadd(mhi, 10, 0); - else { - mlo = multadd(mlo, 10, 0); - mhi = multadd(mhi, 10, 0); - } - } - } - else - for(i = 1;; i++) { - *s++ = dig = quorem(b,S) + '0'; - if (i >= ilim) - break; - b = multadd(b, 10, 0); - } - - /* Round off last digit */ - - b = lshift(b, 1); - j = cmp(b, S); - if (j > 0 || (j == 0 && dig & 1)) { - roundoff: - while(*--s == '9') - if (s == s0) { - k++; - *s++ = '1'; - goto ret; - } - ++*s++; - } - else { - while(*--s == '0'); - s++; - } - ret: - Bfree(b_avail); - Bfree(S); - if (mhi) { - if (mlo && mlo != mhi) - Bfree(mlo); - Bfree(mhi); - } - ret1: - Bfree(b); - *s = 0; - *decpt = k + 1; - if (rve) - *rve = s; - return s0; - } -#endif /* _IO_USE_DTOA */ |