ack/mach/proto/fp/cmf8.c
1988-04-07 11:40:46 +00:00

58 lines
1.1 KiB
C

/*
(c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* $Header$ */
/*
COMPARE DOUBLES
*/
#include "FP_types.h"
#include "get_put.h"
short
cmf8(d1,d2)
_double d1,d2;
{
#define SIGN(x) (((x) < 0) ? -1 : 1)
/*
* return ((d1 < d2) ? 1 : (d1 > d2) ? -1 : 0))
*/
long l1,l2;
unsigned short *s1,*s2;
int sign1,sign2;
l1 = get4((char *)&d1);
l2 = get4((char *)&d2);
sign1 = SIGN(l1);
sign2 = SIGN(l2);
if (sign1 != sign2)
return ((sign1 > 0) ? -1 : 1);
if (l1 != l2) { /* we can decide here */
s1 = (unsigned short *) &l1;
s2 = (unsigned short *) &l2;
/* set both signs positive */
*s1 &= ~0x8000;
*s2 &= ~0x8000;
/* we already know they aren't equal so */
return (sign1 * ((l1 < l2) ? 1 : -1));
}
else { /* decide in 2nd half */
l1 = get4(((char *)&d1 + 4));
l2 = get4(((char *)&d2 + 4));
if (l1 == l2)
return(0);
else {
s1 = (unsigned short *) &l1;
s2 = (unsigned short *) &l2;
if (*s1 == *s2) {
s1++;
s2++;
}
return (sign1 * ((*s1 < *s2) ? 1 : -1));
}
}
}