lib/libc/gdtoa/smisc.c

   1 /* $NetBSD: smisc.c,v 1.5 2012/03/13 21:13:34 christos 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, dplen) CONST char *s; int dplen, nd0, nd; ULong y9;
  40 #else
  41         (CONST char *s, int nd0, int nd, ULong y9, size_t dplen)
  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 += dplen;
  73                 }
  74         else
  75                 s += dplen + 9;
  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  double
  84 ratio
  85 #ifdef KR_headers
  86         (a, b) Bigint *a, *b;
  87 #else
  88         (Bigint *a, Bigint *b)
  89 #endif
  90 {
  91         U da, db;
  92         int k, ka, kb;
  93
  94         dval(&da) = b2d(a, &ka);
  95         dval(&db) = b2d(b, &kb);
  96         k = ka - kb + ULbits*(a->wds - b->wds);
  97 #ifdef IBM
  98         if (k > 0) {
  99                 word0(&da) += (k >> 2)*Exp_msk1;
 100                 if (k &= 3)
 101                         dval(&da) *= 1 << k;
 102                 }
 103         else {
 104                 k = -k;
 105                 word0(&db) += (k >> 2)*Exp_msk1;
 106                 if (k &= 3)
 107                         dval(&db) *= 1 << k;
 108                 }
 109 #else
 110         if (k > 0)
 111                 word0(&da) += k*Exp_msk1;
 112         else {
 113                 k = -k;
 114                 word0(&db) += k*Exp_msk1;
 115                 }
 116 #endif
 117         return dval(&da) / dval(&db);
 118         }
 119
 120 #ifdef INFNAN_CHECK
 121
 122  int
 123 match
 124 #ifdef KR_headers
 125         (sp, t) CONST char **sp, *t;
 126 #else
 127         (CONST char **sp, CONST char *t)
 128 #endif
 129 {
 130         int c, d;
 131         CONST char *s = *sp;
 132
 133         while( (d = *t++) !=0) {
 134                 if ((c = *++s) >= 'A' && c <= 'Z')
 135                         c += 'a' - 'A';
 136                 if (c != d)
 137                         return 0;
 138                 }
 139         *sp = s + 1;
 140         return 1;
 141         }
 142 #endif /* INFNAN_CHECK */
 143
 144  void
 145 #ifdef KR_headers
 146 copybits(c, n, b) ULong *c; int n; Bigint *b;
 147 #else
 148 copybits(ULong *c, int n, Bigint *b)
 149 #endif
 150 {
 151         ULong *ce, *x, *xe;
 152 #ifdef Pack_16
 153         int nw, nw1;
 154 #endif
 155
 156         ce = c + ((unsigned int)(n-1) >> kshift) + 1;
 157         x = b->x;
 158 #ifdef Pack_32
 159         xe = x + b->wds;
 160         while(x < xe)
 161                 *c++ = *x++;
 162 #else
 163         nw = b->wds;
 164         nw1 = nw & 1;
 165         for(xe = x + (nw - nw1); x < xe; x += 2)
 166                 Storeinc(c, x[1], x[0]);
 167         if (nw1)
 168                 *c++ = *x;
 169 #endif
 170         while(c < ce)
 171                 *c++ = 0;
 172         }
 173
 174  ULong
 175 #ifdef KR_headers
 176 any_on(b, k) Bigint *b; int k;
 177 #else
 178 any_on(Bigint *b, int k)
 179 #endif
 180 {
 181         int n, nwds;
 182         ULong *x, *x0, x1, x2;
 183
 184         x = b->x;
 185         nwds = b->wds;
 186         n = (unsigned int)k >> kshift;
 187         if (n > nwds)
 188                 n = nwds;
 189         else if (n < nwds && (k &= kmask)) {
 190                 x1 = x2 = x[n];
 191                 x1 >>= k;
 192                 x1 <<= k;
 193                 if (x1 != x2)
 194                         return 1;
 195                 }
 196         x0 = x;
 197         x += n;
 198         while(x > x0)
 199                 if (*--x)
 200                         return 1;
 201         return 0;
 202         }