source: trunk/minix/lib/ack/fphook/fif4.fc@ 12

/*
  (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/fif4.fc,v 1.1 2005/10/10 15:27:43 beng Exp $ */

/*
        MULTIPLY AND DISMEMBER PARTS (FIF 4)
*/

#include "FP_types.h"
#include "FP_shift.h"

void
fif4(p,x,y)
SINGLE  x,y;
struct fif4_returns *p;
{

        EXTEND  e1,e2;

        extend(&y,&e1,sizeof(SINGLE));
        extend(&x,&e2,sizeof(SINGLE));
                /* do a multiply */
        mul_ext(&e1,&e2);
        e2 = e1;
        compact(&e2,&y,sizeof(SINGLE));
        if (e1.exp < 0) {
                p->ipart = 0;
                p->fpart = y;
                return;
        }
        if (e1.exp > 30 - SGL_M1LEFT) {
                p->ipart = y;
                p->fpart = 0;
                return;
        }
        b64_sft(&e1.mantissa, 63 - e1.exp);
        b64_sft(&e1.mantissa, e1.exp - 63);     /* "loose" low order bits */
        compact(&e1,&(p->ipart),sizeof(SINGLE));
        extend(&(p->ipart), &e2, sizeof(SINGLE));
        extend(&y, &e1, sizeof(SINGLE));
        sub_ext(&e1, &e2);
        compact(&e1, &(p->fpart), sizeof(SINGLE));
}