lib/float/cuf8.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         CONVERT INTEGER TO FLOAT (CUF n 8)
  10
  11         THIS ROUTINE WORKS BY FILLING AN EXTENDED
  12         WITH THE INTEGER VALUE IN EXTENDED FORMAT
  13         AND USES COMPACT() TO PUT IT INTO THE PROPER
  14         FLOATING POINT PRECISION.
  15 */
  16
  17 #include "FP_types.h"
  18
  19 void
  20 cuf8(ss,src)
  21 int     ss;     /* source size */
  22 long    src;    /* largest possible integer to convert */
  23 {
  24         EXTEND  buf;
  25         short   *ipt;
  26         long    i_src;
  27
  28         zrf_ext(&buf);
  29         if (ss == sizeof(long)) {
  30                 buf.exp = 31;
  31                 i_src = src;
  32         }
  33         else    {
  34                 ipt = (short *) &src;
  35                 i_src = (long) *ipt;
  36                 buf.exp = 15;
  37         }
  38         if (i_src == 0) {
  39                 zrf8((DOUBLE *)((void *)&ss));
  40                 return;
  41         }
  42                         /* ESTABLISHED THAT src != 0    */
  43
  44                         /* adjust exponent field        */
  45         if (ss != sizeof(long))
  46                 i_src <<= 16;
  47
  48                         /* move to mantissa field       */
  49         buf.m1 = i_src;
  50
  51                         /* adjust mantissa field        */
  52         nrm_ext(&buf);
  53         compact(&buf,(unsigned long *) (void *)&ss,8);
  54 }