source: trunk/minix/lib/ack/fphook/cmf8.fc@ 10

/*
  (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
  See the copyright notice in the ACK home directory, in the file "Copyright".
*/

/* $Header: /cvsup/minix/src/lib/ack/fphook/cmf8.fc,v 1.1 2005/10/10 15:27:43 beng Exp $ */

/*
        COMPARE DOUBLES (CMF 8)
*/

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

int
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;

#if FL_MSL_AT_LOW_ADDRESS
        l1 = get4((char *)&d1);
        l2 = get4((char *)&d2);
#else
        l1 = get4(((char *)&d1+4));
        l2 = get4(((char *)&d2+4));
#endif
        sign1 = SIGN(l1);
        sign2 = SIGN(l2);
        if (sign1 != sign2) {
                l1 &= 0x7fffffff;
                l2 &= 0x7fffffff;
                if (l1 != 0 || l2 != 0) {
                        return ((sign1 > 0) ? -1 : 1);
                }
        }
        if (l1 != l2)   {       /* we can decide here */
                rv = l1 < l2 ? 1 : -1;
        }
        else    {               /* decide in 2nd half */
                unsigned long u1, u2;
#if FL_MSL_AT_LOW_ADDRESS
                u1 = get4(((char *)&d1 + 4));
                u2 = get4(((char *)&d2 + 4));
#else
                u1 = get4((char *)&d1);
                u2 = get4((char *)&d2);
#endif
                if (u1 == u2)
                        return(0);
                if (u1 < u2) rv = 1;
                else rv = -1;
        }
        return sign1 * rv;
}