ack/mach/proto/fp/cuf4.c

62 lines
1.2 KiB
C
Raw Normal View History

1988-04-07 11:40:46 +00:00
/*
(c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* $Header$ */
1988-04-07 10:57:49 +00:00
/*
CONVERT INTEGER TO FLOAT
THIS ROUTINE WORKS BY FILLING AN EXTENDED
WITH THE INTEGER VALUE IN EXTENDED FORMAT
AND USES COMPACT() TO PUT IT INTO THE PROPER
FLOATING POINT PRECISION.
*/
#include "FP_types.h"
cuf4(ss,src)
int ss; /* source size */
long src; /* largest possible integer to convert */
{
EXTEND buf;
short *ipt;
_float *result;
long i_src;
zrf_ext(&buf);
if (ss == sizeof(long)) {
buf.exp = 33;
i_src = src;
result = (_float *) &src;
}
else {
ipt = (short *) &src;
i_src = (long) *ipt;
buf.exp = 17;
result = (_float *) &ss;
}
#ifdef PRT_STDERR
fprintf(stderr,"CUF4(ds(%d),ss(%d),src(%D))\n\n",4,ss,i_src);
#endif
if (i_src == 0) {
src = 0L;
}
/* ESTABLISHED THAT src != 0 */
/* adjust exponent field */
if (ss != sizeof(long))
i_src <<= 16;
/* move to mantissa field */
buf.m1 = i_src;
/* adjust mantissa field */
nrm_ext(&buf);
#ifdef PRT_STDERR
fprintf(stderr,"CUF() buf.exp after nrm_ext() == %d\n\n",buf.exp);
#endif
compact(&buf,(_double *) result,4);
}