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Diffstat (limited to 'nuttx/libc/stdio/lib_dtoa.c')
-rw-r--r--nuttx/libc/stdio/lib_dtoa.c1641
1 files changed, 0 insertions, 1641 deletions
diff --git a/nuttx/libc/stdio/lib_dtoa.c b/nuttx/libc/stdio/lib_dtoa.c
deleted file mode 100644
index 44290ae32..000000000
--- a/nuttx/libc/stdio/lib_dtoa.c
+++ /dev/null
@@ -1,1641 +0,0 @@
-/****************************************************************************
- * libc/stdio/lib_dtoa.c
- *
- * This file was ported to NuttX by Yolande Cates.
- *
- * Copyright (c) 1990, 1993
- * The Regents of the University of California. All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Chris Torek.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- ****************************************************************************/
-
-/****************************************************************************
- * Included Files
- ****************************************************************************/
-
-#include <nuttx/config.h>
-
-#include <stdint.h>
-#include <string.h>
-
-#include "lib_internal.h"
-
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-
-#ifdef Unsigned_Shifts
-# define Sign_Extend(a,b) if (b < 0) a |= 0xffff0000;
-#else
-# define Sign_Extend(a,b) /* no-op */
-#endif
-
-#ifdef CONFIG_ENDIAN_BIG
-# define word0(x) ((uint32_t *)&x)[0]
-# define word1(x) ((uint32_t *)&x)[1]
-#else
-# define word0(x) ((uint32_t *)&x)[1]
-# define word1(x) ((uint32_t *)&x)[0]
-#endif
-
-#ifdef CONFIG_ENDIAN_BIG
-# 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) (((unsigned short *)a)[1] = (unsigned short)b, \
- ((unsigned short *)a)[0] = (unsigned short)c, a++)
-#endif
-
-#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 */
-
-#define Kmax 15
-
-#define Bcopy(x,y) memcpy((char *)&x->sign, (char *)&y->sign, \
- y->wds*sizeof(long) + 2*sizeof(int))
-
-/****************************************************************************
- * Private Type Definitions
- ****************************************************************************/
-
-struct Bigint
-{
- struct Bigint *next;
- int k, maxwds, sign, wds;
- unsigned long x[1];
-};
-
-typedef struct Bigint Bigint;
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
-static Bigint *freelist[Kmax + 1];
-
-/****************************************************************************
- * Private Functions
- ****************************************************************************/
-
-static Bigint *Balloc(int k)
-{
- int x;
- Bigint *rv;
-
- if ((rv = freelist[k]))
- {
- freelist[k] = rv->next;
- }
- else
- {
- x = 1 << k;
- rv = (Bigint *)lib_malloc(sizeof(Bigint) + (x - 1) * sizeof(long));
- 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;
- }
-}
-
-/* multiply by m and add a */
-
-static Bigint *multadd(Bigint * b, int m, int a)
-{
- int i, wds;
- unsigned long *x, y;
-#ifdef Pack_32
- unsigned long xi, z;
-#endif
- Bigint *b1;
-
- wds = b->wds;
- x = b->x;
- i = 0;
- do
- {
-#ifdef Pack_32
- xi = *x;
- y = (xi & 0xffff) * m + a;
- z = (xi >> 16) * m + (y >> 16);
- a = (int)(z >> 16);
- *x++ = (z << 16) + (y & 0xffff);
-#else
- y = *x * m + a;
- a = (int)(y >> 16);
- *x++ = y & 0xffff;
-#endif
- }
- while (++i < wds);
- if (a)
- {
- if (wds >= b->maxwds)
- {
- b1 = Balloc(b->k + 1);
- Bcopy(b1, b);
- Bfree(b);
- b = b1;
- }
- b->x[wds++] = a;
- b->wds = wds;
- }
- return b;
-}
-
-static int hi0bits(unsigned long x)
-{
- 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(unsigned long *y)
-{
- int k;
- unsigned long 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(int i)
-{
- Bigint *b;
-
- b = Balloc(1);
- b->x[0] = i;
- b->wds = 1;
- return b;
-}
-
-static Bigint *mult(Bigint * a, Bigint * b)
-{
- Bigint *c;
- int k, wa, wb, wc;
- unsigned long carry, y, z;
- unsigned long *x, *xa, *xae, *xb, *xbe, *xc, *xc0;
-#ifdef Pack_32
- uint32_t z2;
-#endif
-
- if (a->wds < b->wds)
- {
- c = a;
- a = b;
- b = c;
- }
-
- k = a->k;
- wa = a->wds;
- wb = b->wds;
- wc = wa + wb;
- if (wc > a->maxwds)
- {
- k++;
- }
- c = Balloc(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;
-#ifdef Pack_32
- 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;
- }
- }
-#else
- for (; xb < xbe; xc0++)
- {
- if ((y = *xb++))
- {
- x = xa;
- xc = xc0;
- carry = 0;
- do
- {
- z = *x++ * y + *xc + carry;
- carry = z >> 16;
- *xc++ = z & 0xffff;
- }
- while (x < xae);
- *xc = carry;
- }
- }
-#endif
- for (xc0 = c->x, xc = xc0 + wc; wc > 0 && !*--xc; --wc);
- c->wds = wc;
- return c;
-}
-
-static Bigint *p5s;
-
-static Bigint *pow5mult(Bigint * b, int k)
-{
- Bigint *b1, *p5, *p51;
- int i;
- static int p05[3] = { 5, 25, 125 };
-
- if ((i = k & 3))
- b = multadd(b, p05[i - 1], 0);
-
- if (!(k >>= 2))
- {
- return b;
- }
-
- if (!(p5 = p5s))
- {
- /* first time */
- p5 = p5s = i2b(625);
- p5->next = 0;
- }
-
- for (;;)
- {
- if (k & 1)
- {
- b1 = mult(b, p5);
- Bfree(b);
- b = b1;
- }
- if (!(k >>= 1))
- {
- break;
- }
-
- if (!(p51 = p5->next))
- {
- p51 = p5->next = mult(p5, p5);
- p51->next = 0;
- }
- p5 = p51;
- }
- return b;
-}
-
-static Bigint *lshift(Bigint * b, int k)
-{
- int i, k1, n, n1;
- Bigint *b1;
- unsigned long *x, *x1, *xe, z;
-
-#ifdef Pack_32
- n = k >> 5;
-#else
- n = k >> 4;
-#endif
- k1 = b->k;
- n1 = n + b->wds + 1;
- for (i = b->maxwds; n1 > i; i <<= 1)
- {
- k1++;
- }
- b1 = Balloc(k1);
- x1 = b1->x;
- for (i = 0; i < n; i++)
- {
- *x1++ = 0;
- }
- x = b->x;
- xe = x + b->wds;
-#ifdef Pack_32
- if (k &= 0x1f)
- {
- k1 = 32 - k;
- z = 0;
- do
- {
- *x1++ = *x << k | z;
- z = *x++ >> k1;
- }
- while (x < xe);
- if ((*x1 = z))
- {
- ++n1;
- }
- }
-#else
- if (k &= 0xf)
- {
- k1 = 16 - k;
- z = 0;
- do
- {
- *x1++ = ((*x << k) & 0xffff) | z;
- z = *x++ >> k1;
- }
- while (x < xe);
- if ((*x1 = z))
- {
- ++n1;
- }
- }
-#endif
- else
- do
- {
- *x1++ = *x++;
- }
- while (x < xe);
- b1->wds = n1 - 1;
- Bfree(b);
- return b1;
-}
-
-static int cmp(Bigint * a, Bigint * b)
-{
- unsigned long *xa, *xa0, *xb, *xb0;
- int i, j;
-
- i = a->wds;
- j = b->wds;
-#ifdef CONFIG_DEBUG_LIB
- if (i > 1 && !a->x[i - 1])
- {
- ldbg("cmp called with a->x[a->wds-1] == 0\n");
- }
- if (j > 1 && !b->x[j - 1])
- {
- ldbg("cmp called with b->x[b->wds-1] == 0\n");
- }
-#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;
- int i, wa, wb;
- long borrow, y; /* We need signed shifts here. */
- unsigned long *xa, *xae, *xb, *xbe, *xc;
-#ifdef Pack_32
- int32_t z;
-#endif
-
- i = cmp(a, b);
- if (!i)
- {
- c = Balloc(0);
- 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);
- 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 Pack_32
- 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);
- }
-#else
- do
- {
- y = *xa++ - *xb++ + borrow;
- borrow = y >> 16;
- Sign_Extend(borrow, y);
- *xc++ = y & 0xffff;
- }
- while (xb < xbe);
- while (xa < xae)
- {
- y = *xa++ + borrow;
- borrow = y >> 16;
- Sign_Extend(borrow, y);
- *xc++ = y & 0xffff;
- }
-#endif
- while (!*--xc)
- wa--;
- c->wds = wa;
- return c;
-}
-
-static Bigint *d2b(double d, int *e, int *bits)
-{
- Bigint *b;
- int de, i, k;
- unsigned long *x, y, z;
-
-#ifdef Pack_32
- b = Balloc(1);
-#else
- b = Balloc(2);
-#endif
- x = b->x;
-
- z = word0(d) & Frac_mask;
- word0(d) &= 0x7fffffff; /* clear sign bit, which we ignore */
- if ((de = (int)(word0(d) >> Exp_shift)))
- z |= Exp_msk1;
-#ifdef Pack_32
- if ((y = word1(d)))
- {
- if ((k = lo0bits(&y)))
- {
- x[0] = y | z << (32 - k);
- z >>= k;
- }
- else
- x[0] = y;
- i = b->wds = (x[1] = z) ? 2 : 1;
- }
- else
- {
-#ifdef CONFIG_DEBUG_LIB
- if (!z)
- {
- ldbg("Zero passed to d2b\n");
- }
-#endif
- k = lo0bits(&z);
- x[0] = z;
- i = b->wds = 1;
- k += 32;
- }
-#else
- if ((y = word1(d)))
- {
- if ((k = lo0bits(&y)))
- if (k >= 16)
- {
- x[0] = y | ((z << (32 - k)) & 0xffff);
- x[1] = z >> (k - 16) & 0xffff;
- x[2] = z >> k;
- i = 2;
- }
- else
- {
- x[0] = y & 0xffff;
- x[1] = (y >> 16) | ((z << (16 - k)) & 0xffff);
- x[2] = z >> k & 0xffff;
- x[3] = z >> (k + 16);
- i = 3;
- }
- else
- {
- x[0] = y & 0xffff;
- x[1] = y >> 16;
- x[2] = z & 0xffff;
- x[3] = z >> 16;
- i = 3;
- }
- }
- else
- {
-#ifdef CONFIG_DEBUG_LIB
- if (!z)
- {
- ldbg("Zero passed to d2b\n");
- }
-#endif
- k = lo0bits(&z);
- if (k >= 16)
- {
- x[0] = z;
- i = 0;
- }
- else
- {
- x[0] = z & 0xffff;
- x[1] = z >> 16;
- i = 1;
- }
- k += 32;
- }
- while (!x[i])
- --i;
- b->wds = i + 1;
-#endif
- if (de)
- {
- *e = de - Bias - (P - 1) + k;
- *bits = P - k;
- }
- else
- {
- *e = de - Bias - (P - 1) + 1 + k;
-#ifdef Pack_32
- *bits = 32 * i - hi0bits(x[i - 1]);
-#else
- *bits = (i + 2) * 16 - hi0bits(x[i]);
-#endif
- }
- return b;
-}
-
-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 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
-static const double bigtens[] = { 1e16, 1e32 };
-static const double tinytens[] = { 1e-16, 1e-32 };
-
-# define n_bigtens 2
-#endif
-
-static int quorem(Bigint * b, Bigint * S)
-{
- int n;
- long borrow, y;
- unsigned long carry, q, ys;
- unsigned long *bx, *bxe, *sx, *sxe;
-#ifdef Pack_32
- int32_t z;
- uint32_t si, zs;
-#endif
-
- n = S->wds;
-#ifdef CONFIG_DEBUG_LIB
- if (b->wds > n)
- {
- ldbg("oversize b in quorem\n");
- }
-#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 CONFIG_DEBUG_LIB
- if (q > 9)
- {
- ldbg("oversized quotient in quorem\n");
- }
-#endif
- if (q)
- {
- borrow = 0;
- carry = 0;
- do
- {
-#ifdef Pack_32
- 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);
-#else
- ys = *sx++ * q + carry;
- carry = ys >> 16;
- y = *bx - (ys & 0xffff) + borrow;
- borrow = y >> 16;
- Sign_Extend(borrow, y);
- *bx++ = y & 0xffff;
-#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 Pack_32
- 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);
-#else
- ys = *sx++ + carry;
- carry = ys >> 16;
- y = *bx - (ys & 0xffff) + borrow;
- borrow = y >> 16;
- Sign_Extend(borrow, y);
- *bx++ = y & 0xffff;
-#endif
- }
- while (sx <= sxe);
- bx = b->x;
- bxe = bx + n;
- if (!*bxe)
- {
- while (--bxe > bx && !*bxe)
- --n;
- b->wds = n;
- }
- }
- return q;
-}
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
-/* 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 int32_t
- * calculation.
- */
-
-char *__dtoa(double d, int mode, int ndigits, int *decpt, int *sign, char **rve)
-{
- /* 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. */
-
- int bbits, b2, b5, be, dig, i, ieps, ilim = 0, ilim0, ilim1 = 0,
- j, j_1, k, k0, k_check, leftright, m2, m5, s2, s5, spec_case = 0, try_quick;
- long L;
- int denorm;
- unsigned long x;
- Bigint *b, *b1, *delta, *mlo = NULL, *mhi, *S;
- double d2, ds, eps;
- char *s, *s0;
- static Bigint *result;
- static int result_k;
-
- if (result)
- {
- result->k = result_k;
- result->maxwds = 1 << result_k;
- Bfree(result);
- result = 0;
- }
-
- if (word0(d) & Sign_bit)
- {
- /* set sign for everything, including 0's and NaNs */
- *sign = 1;
- word0(d) &= ~Sign_bit; /* clear sign bit */
- }
- else
- {
- *sign = 0;
- }
-
-#if defined(IEEE_Arith)
-# ifdef IEEE_Arith
- if ((word0(d) & Exp_mask) == Exp_mask)
-#else
- if (word0(d) == 0x8000)
-#endif
- {
- /* Infinity or NaN */
- *decpt = 9999;
- s =
-#ifdef IEEE_Arith
- !word1(d) && !(word0(d) & 0xfffff) ? "Infinity" :
-#endif
- "NaN";
- if (rve)
- *rve =
-#ifdef IEEE_Arith
- s[3] ? s + 8 :
-#endif
- s + 3;
- return s;
- }
-#endif
- if (!d)
- {
- *decpt = 1;
- s = "0";
- if (rve)
- *rve = s + 1;
- return s;
- }
-
- b = d2b(d, &be, &bbits);
- if ((i = (int)(word0(d) >> Exp_shift1 & (Exp_mask >> Exp_shift1))))
- {
- d2 = d;
- word0(d2) &= Frac_mask1;
- 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;
- 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;
- word0(d2) -= 31 * Exp_msk1; /* adjust exponent */
- i -= (Bias + (P - 1) - 1) + 1;
- denorm = 1;
- }
-
- 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;
- }
- }
-
- j = sizeof(unsigned long);
- for (result_k = 0;
- (signed)(sizeof(Bigint) - sizeof(unsigned long) + j) <= i;
- j <<= 1)
- {
- result_k++;
- }
-
- 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 ((j_1 = -k))
- {
- d *= tens[j_1 & 0xf];
- for (j = j_1 >> 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.;
- 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 = (int)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 = (int)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)
- {
- S = mhi = 0;
- if (ilim < 0 || d <= 5 * ds)
- goto no_digits;
- goto one_digit;
- }
-
- for (i = 1;; i++)
- {
- L = (int)(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;
- mhi = mlo = 0;
- if (leftright)
- {
- if (mode < 2)
- {
- i = denorm ? be + (Bias + (P - 1) - 1 + 1) : 1 + P - bbits;
- }
- 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(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)
- {
- mhi = pow5mult(mhi, m5);
- b1 = mult(mhi, b);
- Bfree(b);
- b = b1;
- }
- if ((j = b5 - m5))
- b = pow5mult(b, j);
- }
- else
- {
- b = pow5mult(b, b5);
- }
- }
-
- S = i2b(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) && word0(d) & Exp_mask)
- {
- /* 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.
- */
-
-#ifdef Pack_32
- if ((i = ((s5 ? 32 - hi0bits(S->x[S->wds - 1]) : 1) + s2) & 0x1f))
- {
- i = 32 - i;
- }
-#else
- if ((i = ((s5 ? 32 - hi0bits(S->x[S->wds - 1]) : 1) + s2) & 0xf))
- {
- i = 16 - i;
- }
-#endif
-
- 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. */
-
- mlo = mhi;
- if (spec_case)
- {
- mhi = Balloc(mhi->k);
- Bcopy(mhi, mlo);
- mhi = lshift(mhi, Log2P);
- }
-
- 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);
- delta = diff(S, mhi);
- j_1 = delta->sign ? 1 : cmp(b, delta);
- Bfree(delta);
-#ifndef ROUND_BIASED
- if (j_1 == 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 ((j_1 > 0))
- {
- b = lshift(b, 1);
- j_1 = cmp(b, S);
- if ((j_1 > 0 || (j_1 == 0 && (dig & 1))) && dig++ == '9')
- {
- goto round_9_up;
- }
- }
-
- *s++ = dig;
- goto ret;
- }
-
- if (j_1 > 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(S);
- if (mhi)
- {
- if (mlo && mlo != mhi)
- {
- Bfree(mlo);
- }
-
- Bfree(mhi);
- }
-ret1:
- Bfree(b);
- if (s == s0)
- { /* don't return empty string */
- *s++ = '0';
- k = 0;
- }
-
- *s = 0;
- *decpt = k + 1;
- if (rve)
- {
- *rve = s;
- }
-
- return s0;
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-11 06:46:22 +0000