/*-
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Donn Seeley at UUNET Technologies, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <machine/asm.h>

        /* .asciz "@(#)urem.s   8.1 (Berkeley) 6/4/93" */
RCSID("$NetBSD: urem.S,v 1.3 2011/01/25 04:45:28 matt Exp $")

/*
 * Unsigned modulus, PCC flavor.
 * urem() takes an ordinary dividend/divisor pair;
 * aurem() takes a pointer to a dividend and an ordinary divisor.
 */

#define DIVIDEND        4(%ap)
#define DIVISOR         8(%ap)

ASENTRY(__urem,0)
        movl    DIVISOR,%r2
        jlss    Leasy           # big divisor: settle by comparison
        movl    DIVIDEND,%r0
        jlss    Lhard           # big dividend: need extended division
        divl3   %r2,%r0,%r1     # small divisor and dividend: signed modulus
        mull2   %r2,%r1
        subl2   %r1,%r0
        ret
Lhard:
        clrl    %r1
        ediv    %r2,%r0,%r1,%r0
        ret
Leasy:
        subl3   %r2,DIVIDEND,%r0
        jcc     Ldifference     # if divisor goes in once, return difference
        movl    DIVIDEND,%r0    # if divisor is bigger, return dividend
Ldifference:
        ret
END(__urem)

ASENTRY(__aurem,0)
        movl    DIVIDEND,%r3
        movl    DIVISOR,%r2
        jlss    La_easy         # big divisor: settle by comparison
        movl    (%r3),%r0
        jlss    La_hard         # big dividend: need extended division
        divl3   %r2,%r0,%r1     # small divisor and dividend: signed modulus
        mull2   %r2,%r1
        subl2   %r1,%r0
        movl    %r0,(%r3)               # leave the value of the assignment in %r0
        ret
La_hard:
        clrl    %r1
        ediv    %r2,%r0,%r1,%r0
        movl    %r0,(%r3)
        ret
La_easy:
        subl3   %r2,(%r3),%r0
        jcs     La_dividend     # if divisor is bigger, leave dividend alone
        movl    %r0,(%r3)               # if divisor goes in once, store difference
        ret
La_dividend:
        movl    (%r3),%r0
        ret
END(__aurem)