lib/libc/gdtoa/smisc.c

   1 /* $NetBSD: smisc.c,v 1.2 2006/01/25 15:27:42 kleink Exp $ */
   2
   3 /****************************************************************
   4
   5 The author of this software is David M. Gay.
   6
   7 Copyright (C) 1998, 1999 by Lucent Technologies
   8 All Rights Reserved
   9
  10 Permission to use, copy, modify, and distribute this software and
  11 its documentation for any purpose and without fee is hereby
  12 granted, provided that the above copyright notice appear in all
  13 copies and that both that the copyright notice and this
  14 permission notice and warranty disclaimer appear in supporting
  15 documentation, and that the name of Lucent or any of its entities
  16 not be used in advertising or publicity pertaining to
  17 distribution of the software without specific, written prior
  18 permission.
  19
  20 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
  22 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
  23 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  24 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
  25 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  26 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
  27 THIS SOFTWARE.
  28
  29 ****************************************************************/
  30
  31 /* Please send bug reports to David M. Gay (dmg at acm dot org,
  32  * with " at " changed at "@" and " dot " changed to ".").      */
  33
  34 #include "gdtoaimp.h"
  35
  36  Bigint *
  37 s2b
  38 #ifdef KR_headers
  39         (s, nd0, nd, y9) CONST char *s; int nd0, nd; ULong y9;
  40 #else
  41         (CONST char *s, int nd0, int nd, ULong y9)
  42 #endif
  43 {
  44         Bigint *b;
  45         int i, k;
  46         Long x, y;
  47
  48         x = (nd + 8) / 9;
  49         for(k = 0, y = 1; x > y; y <<= 1, k++) ;
  50 #ifdef Pack_32
  51         b = Balloc(k);
  52         if (b == NULL)
  53                 return NULL;
  54         b->x[0] = y9;
  55         b->wds = 1;
  56 #else
  57         b = Balloc(k+1);
  58         if (b == NULL)
  59                 return NULL;
  60         b->x[0] = y9 & 0xffff;
  61         b->wds = (b->x[1] = y9 >> 16) ? 2 : 1;
  62 #endif
  63
  64         i = 9;
  65         if (9 < nd0) {
  66                 s += 9;
  67                 do  {
  68                         b = multadd(b, 10, *s++ - '0');
  69                         if (b == NULL)
  70                                 return NULL;
  71                         } while(++i < nd0);
  72                 s++;
  73                 }
  74         else
  75                 s += 10;
  76         for(; i < nd; i++) {
  77                 b = multadd(b, 10, *s++ - '0');
  78                 if (b == NULL)
  79                         return NULL;
  80                 }
  81         return b;
  82         }
  83
  84  double
  85 ratio
  86 #ifdef KR_headers
  87         (a, b) Bigint *a, *b;
  88 #else
  89         (Bigint *a, Bigint *b)
  90 #endif
  91 {
  92         double da, db;
  93         int k, ka, kb;
  94
  95         dval(da) = b2d(a, &ka);
  96         dval(db) = b2d(b, &kb);
  97         k = ka - kb + ULbits*(a->wds - b->wds);
  98 #ifdef IBM
  99         if (k > 0) {
 100                 word0(da) += (k >> 2)*Exp_msk1;
 101                 if (k &= 3)
 102                         dval(da) *= 1 << k;
 103                 }
 104         else {
 105                 k = -k;
 106                 word0(db) += (k >> 2)*Exp_msk1;
 107                 if (k &= 3)
 108                         dval(db) *= 1 << k;
 109                 }
 110 #else
 111         if (k > 0)
 112                 word0(da) += k*Exp_msk1;
 113         else {
 114                 k = -k;
 115                 word0(db) += k*Exp_msk1;
 116                 }
 117 #endif
 118         return dval(da) / dval(db);
 119         }
 120
 121 #ifdef INFNAN_CHECK
 122
 123  int
 124 match
 125 #ifdef KR_headers
 126         (sp, t) CONST char **sp, *t;
 127 #else
 128         (CONST char **sp, CONST char *t)
 129 #endif
 130 {
 131         int c, d;
 132         CONST char *s = *sp;
 133
 134         while( (d = *t++) !=0) {
 135                 if ((c = *++s) >= 'A' && c <= 'Z')
 136                         c += 'a' - 'A';
 137                 if (c != d)
 138                         return 0;
 139                 }
 140         *sp = s + 1;
 141         return 1;
 142         }
 143 #endif /* INFNAN_CHECK */
 144
 145  void
 146 #ifdef KR_headers
 147 copybits(c, n, b) ULong *c; int n; Bigint *b;
 148 #else
 149 copybits(ULong *c, int n, Bigint *b)
 150 #endif
 151 {
 152         ULong *ce, *x, *xe;
 153 #ifdef Pack_16
 154         int nw, nw1;
 155 #endif
 156
 157         ce = c + ((unsigned int)(n-1) >> kshift) + 1;
 158         x = b->x;
 159 #ifdef Pack_32
 160         xe = x + b->wds;
 161         while(x < xe)
 162                 *c++ = *x++;
 163 #else
 164         nw = b->wds;
 165         nw1 = nw & 1;
 166         for(xe = x + (nw - nw1); x < xe; x += 2)
 167                 Storeinc(c, x[1], x[0]);
 168         if (nw1)
 169                 *c++ = *x;
 170 #endif
 171         while(c < ce)
 172                 *c++ = 0;
 173         }
 174
 175  ULong
 176 #ifdef KR_headers
 177 any_on(b, k) Bigint *b; int k;
 178 #else
 179 any_on(Bigint *b, int k)
 180 #endif
 181 {
 182         int n, nwds;
 183         ULong *x, *x0, x1, x2;
 184
 185         x = b->x;
 186         nwds = b->wds;
 187         n = (unsigned int)k >> kshift;
 188         if (n > nwds)
 189                 n = nwds;
 190         else if (n < nwds && (k &= kmask)) {
 191                 x1 = x2 = x[n];
 192                 x1 >>= k;
 193                 x1 <<= k;
 194                 if (x1 != x2)
 195                         return 1;
 196                 }
 197         x0 = x;
 198         x += n;
 199         while(x > x0)
 200                 if (*--x)
 201                         return 1;
 202         return 0;
 203         }