ack/mach/proto/fp/cmf8.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 (CMF 8)
*/

#include	"FP_types.h"
#include	"get_put.h"

cmf8(d1,d2)
_double	d1,d2;
{
#define	SIGN(x)	(((x) < 0) ? -1 : 1)
		/*
		 * return ((d1 < d2) ? 1 : (d1 > d2) ? -1 : 0))
		 */
	long	l1,l2;
	int	sign1,sign2;
	int	rv;

	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 */
		rv = l1 < l2 ? 1 : -1;
	}
	else	{ 		/* decide in 2nd half */
		l1 = get4(((char *)&d1 + 4));
		l2 = get4(((char *)&d2 + 4));
		if (l1 == l2)
			return(0);
		if (l1 >= 0)
			rv = l1 < l2 || l2 < 0 ? 1 : -1;
		else if (l2 >= 0) rv = -1;
		else rv = l1 < l2 ? 1 : -1;
	}
	return sign1 * rv;
}