xref: /minix/common/lib/libc/arch/vax/gen/udiv.S (revision 83ee113e)
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Donn Seeley at UUNET Technologies, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <machine/asm.h>
34
35	/* .asciz "@(#)udiv.s	8.1 (Berkeley) 6/4/93" */
36RCSID("$NetBSD: udiv.S,v 1.3 2011/01/25 04:45:28 matt Exp $")
37
38/*
39 * Unsigned division, PCC flavor.
40 * udiv() takes an ordinary dividend/divisor pair;
41 * audiv() takes a pointer to a dividend and an ordinary divisor.
42 */
43
44#define	DIVIDEND	4(%ap)
45#define	DIVISOR		8(%ap)
46
47ASENTRY(__udiv,0)
48	movl	DIVISOR,%r2
49	jlss	Leasy		# big divisor: settle by comparison
50	movl	DIVIDEND,%r0
51	jlss	Lhard		# big dividend: extended division
52	divl2	%r2,%r0		# small divisor and dividend: signed division
53	ret
54Lhard:
55	clrl	%r1
56	ediv	%r2,%r0,%r0,%r1
57	ret
58Leasy:
59	cmpl	DIVIDEND,%r2
60	jgequ	Lone		# if dividend is as big or bigger, return 1
61	clrl	%r0		# else return 0
62	ret
63Lone:
64	movl	$1,%r0
65	ret
66END(__udiv)
67
68ASENTRY(__audiv,0)
69	movl	DIVIDEND,%r3
70	movl	DIVISOR,%r2
71	jlss	La_easy		# big divisor: settle by comparison
72	movl	(%r3),%r0
73	jlss	La_hard		# big dividend: extended division
74	divl2	%r2,%r0		# small divisor and dividend: signed division
75	movl	%r0,(%r3)		# leave the value of the assignment in %r0
76	ret
77La_hard:
78	clrl	%r1
79	ediv	%r2,%r0,%r0,%r1
80	movl	%r0,(%r3)
81	ret
82La_easy:
83	cmpl	(%r3),%r2
84	jgequ	La_one		# if dividend is as big or bigger, return 1
85	clrl	%r0		# else return 0
86	clrl	(%r3)
87	ret
88La_one:
89	movl	$1,%r0
90	movl	%r0,(%r3)
91	ret
92END(__audiv)
93