xref: /openbsd/sys/lib/libkern/arch/m88k/modsi3.S (revision d415bd75)
1/*	$OpenBSD: modsi3.S,v 1.1 2013/06/07 17:31:31 miod Exp $	*/
2
3/*
4 * Copyright (c) 2013 Miodrag Vallat.
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19
20#include <machine/asm.h>
21
22/*
23 * int __modsi3(int n, int d);
24 */
25
26ENTRY(__modsi3)
27	/* if divider is zero, trap */
28	bcnd	ne0, %r3, 1f
29	tb0	0, %r0, 503
301:
31
32	bb1	31, %r2, 1f
33	bb1	31, %r3, 2f
34
35	/* both operands are positive */
36	divu	%r4, %r2, %r3
379:
38	mul	%r5, %r4, %r3
39	jmp.n	%r1
40	 subu	%r2, %r2, %r5
41
421:
43	bb1	31, %r3, 3f
44
45	/* r2 is negative, r3 is positive */
46	subu	%r4, %r0, %r2
47	divu	%r5, %r4, %r3
48	subu	%r4, %r0, %r5
49	br	9b
50
512:
52	/* r2 is positive, r3 is negative */
53	subu	%r5, %r0, %r3
54	divu	%r4, %r2, %r5
55	subu	%r4, %r0, %r4
56	br	9b
57
583:
59	/* both operands are negative */
60	subu	%r4, %r0, %r2
61	subu	%r5, %r0, %r3
62	divu	%r4, %r4, %r5
63	br	9b
64END(__modsi3)
65