lib/float/cmf8.c

   1 /*
   2   (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3   See the copyright notice in the ACK home directory, in the file "Copyright".
   4 */
   5
   6 /* $Header$ */
   7
   8 /*
   9         COMPARE DOUBLES (CMF 8)
  10 */
  11
  12 #include        "FP_types.h"
  13 #include        "get_put.h"
  14
  15 int
  16 cmf8(d1,d2)
  17 DOUBLE  d1,d2;
  18 {
  19 #define SIGN(x) (((x) < 0) ? -1 : 1)
  20                 /*
  21                  * return ((d1 < d2) ? 1 : (d1 > d2) ? -1 : 0))
  22                  */
  23         long    l1,l2;
  24         int     sign1,sign2;
  25         int     rv;
  26
  27 #if FL_MSL_AT_LOW_ADDRESS
  28         l1 = get4((char *)&d1);
  29         l2 = get4((char *)&d2);
  30 #else
  31         l1 = get4(((char *)&d1+4));
  32         l2 = get4(((char *)&d2+4));
  33 #endif
  34         sign1 = SIGN(l1);
  35         sign2 = SIGN(l2);
  36         if (sign1 != sign2) {
  37                 l1 &= 0x7fffffff;
  38                 l2 &= 0x7fffffff;
  39                 if (l1 != 0 || l2 != 0) {
  40                         return ((sign1 > 0) ? -1 : 1);
  41                 }
  42         }
  43         if (l1 != l2)   {       /* we can decide here */
  44                 rv = l1 < l2 ? 1 : -1;
  45         }
  46         else    {               /* decide in 2nd half */
  47                 unsigned long u1, u2;
  48 #if FL_MSL_AT_LOW_ADDRESS
  49                 u1 = get4(((char *)&d1 + 4));
  50                 u2 = get4(((char *)&d2 + 4));
  51 #else
  52                 u1 = get4((char *)&d1);
  53                 u2 = get4((char *)&d2);
  54 #endif
  55                 if (u1 == u2)
  56                         return(0);
  57                 if (u1 < u2) rv = 1;
  58                 else rv = -1;
  59         }
  60         return sign1 * rv;
  61 }