/*      $NetBSD: divsfm.c,v 1.5 2012/02/04 17:03:09 skrll Exp $ */

/*      $OpenBSD: divsfm.c,v 1.4 2001/03/29 03:58:17 mickey Exp $       */

/*
 * Copyright 1996 1995 by Open Software Foundation, Inc.
 *              All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appears in all copies and
 * that both the copyright notice and this permission notice appear in
 * supporting documentation.
 *
 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */
/*
 * pmk1.1
 */
/*
 * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
 *
 * To anyone who acknowledges that this file is provided "AS IS"
 * without any express or implied warranty:
 *     permission to use, copy, modify, and distribute this file
 * for any purpose is hereby granted without fee, provided that
 * the above copyright notice and this notice appears in all
 * copies, and that the name of Hewlett-Packard Company not be
 * used in advertising or publicity pertaining to distribution
 * of the software without specific, written prior permission.
 * Hewlett-Packard Company makes no representations about the
 * suitability of this software for any purpose.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: divsfm.c,v 1.5 2012/02/04 17:03:09 skrll Exp $");

#include "md.h"

void
divsfm(int opnd1, int opnd2, struct mdsfu_register *result)
{
        register int sign, op1_sign;

        /* check divisor for zero */
        if (opnd2 == 0) {
                overflow = true;
                return;
        }

        /* get sign of result */
        sign = opnd1 ^ opnd2;

        /* get absolute value of operands */
        if (opnd1 < 0) {
                opnd1 = -opnd1;
                op1_sign = true;
        }
        else op1_sign = false;
        if (opnd2 < 0) opnd2 = -opnd2;

        /*
         * check for overflow
         *
         * if abs(opnd1) < 0, then opnd1 = -2**31
         * and abs(opnd1) >= abs(opnd2) always
         */
        if (opnd1 >= opnd2 || opnd1 < 0) {
                /* check for opnd2 = -2**31 */
                if (opnd2 < 0 && opnd1 != opnd2) {
                        result_hi = 0;          /* remainder = 0 */
                        result_lo = opnd1 << 1;
                }
                else {
                        overflow = true;
                        return;
                }
        }
        else {
                /* do the divide */
                divu(opnd1,0,opnd2,result);

                /* return positive residue */
                if (op1_sign && result_hi) {
                        result_hi = opnd2 - result_hi;
                        result_lo++;
                }
        }

        /* check for overflow */
        if (result_lo < 0) {
                overflow = true;
                return;
        }
        overflow = false;

        /* return appropriately signed result */
        if (sign<0) result_lo = -result_lo;
        return;
}