xref: /netbsd-src/common/lib/libc/arch/vax/gen/udiv.S (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
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#if defined(LIBC_SCCS) && !defined(lint)
34	/* .asciz "@(#)udiv.s	8.1 (Berkeley) 6/4/93" */
35	.asciz "$NetBSD: udiv.S,v 1.2 2005/12/24 08:33:32 matt Exp $"
36#endif /* LIBC_SCCS and not lint */
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#include <machine/asm.h>
45
46#define	DIVIDEND	4(%ap)
47#define	DIVISOR		8(%ap)
48
49#ifdef __ELF__
50ASENTRY(__udiv,0)
51#else
52ASENTRY(udiv,0)
53#endif
54	movl	DIVISOR,%r2
55	jlss	Leasy		# big divisor: settle by comparison
56	movl	DIVIDEND,%r0
57	jlss	Lhard		# big dividend: extended division
58	divl2	%r2,%r0		# small divisor and dividend: signed division
59	ret
60Lhard:
61	clrl	%r1
62	ediv	%r2,%r0,%r0,%r1
63	ret
64Leasy:
65	cmpl	DIVIDEND,%r2
66	jgequ	Lone		# if dividend is as big or bigger, return 1
67	clrl	%r0		# else return 0
68	ret
69Lone:
70	movl	$1,%r0
71	ret
72
73#ifdef __ELF__
74ASENTRY(__audiv,0)
75#else
76ASENTRY(audiv,0)
77#endif
78	movl	DIVIDEND,%r3
79	movl	DIVISOR,%r2
80	jlss	La_easy		# big divisor: settle by comparison
81	movl	(%r3),%r0
82	jlss	La_hard		# big dividend: extended division
83	divl2	%r2,%r0		# small divisor and dividend: signed division
84	movl	%r0,(%r3)		# leave the value of the assignment in %r0
85	ret
86La_hard:
87	clrl	%r1
88	ediv	%r2,%r0,%r0,%r1
89	movl	%r0,(%r3)
90	ret
91La_easy:
92	cmpl	(%r3),%r2
93	jgequ	La_one		# if dividend is as big or bigger, return 1
94	clrl	%r0		# else return 0
95	clrl	(%r3)
96	ret
97La_one:
98	movl	$1,%r0
99	movl	%r0,(%r3)
100	ret
101