contrib/gdtoa/smisc.c

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