xref: /openbsd/sys/lib/libkern/moddi3.c (revision 78b63d65)
1 /*	$OpenBSD: moddi3.c,v 1.2 1997/11/07 15:56:45 niklas Exp $	*/
2 /*	$NetBSD: moddi3.c,v 1.5 1995/10/07 09:26:31 mycroft Exp $	*/
3 
4 /*-
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This software was developed by the Computer Systems Engineering group
9  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10  * contributed to Berkeley.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #if defined(LIBC_SCCS) && !defined(lint)
42 #if 0
43 static char sccsid[] = "@(#)moddi3.c	8.1 (Berkeley) 6/4/93";
44 #else
45 static char rcsid[] = "$OpenBSD: moddi3.c,v 1.2 1997/11/07 15:56:45 niklas Exp $";
46 #endif
47 #endif /* LIBC_SCCS and not lint */
48 
49 #include "quad.h"
50 
51 /*
52  * Return remainder after dividing two signed quads.
53  *
54  * XXX
55  * If -1/2 should produce -1 on this machine, this code is wrong.
56  */
57 quad_t
58 __moddi3(a, b)
59 	quad_t a, b;
60 {
61 	u_quad_t ua, ub, ur;
62 	int neg;
63 
64 	if (a < 0)
65 		ua = -(u_quad_t)a, neg = 1;
66 	else
67 		ua = a, neg = 0;
68 	if (b < 0)
69 		ub = -(u_quad_t)b, neg ^= 1;
70 	else
71 		ub = b;
72 	(void)__qdivrem(ua, ub, &ur);
73 	return (neg ? -ur : ur);
74 }
75