xref: /openbsd/lib/libc/quad/moddi3.c (revision 4cfece93)
1 /*	$OpenBSD: moddi3.c,v 1.6 2005/08/08 08:05:35 espie Exp $ */
2 /*-
3  * Copyright (c) 1992, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This software was developed by the Computer Systems Engineering group
7  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
8  * contributed to Berkeley.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "quad.h"
36 
37 /*
38  * Return remainder after dividing two signed quads.
39  *
40  * XXX	we assume a % b < 0 iff a < 0, but this is actually machine-dependent.
41  */
42 quad_t
43 __moddi3(quad_t a, quad_t b)
44 {
45 	u_quad_t ua, ub, ur;
46 	int neg = 0;
47 
48 	ua = a;
49 	ub = b;
50 
51 	if (a < 0)
52 		ua = -ua, neg ^= 1;
53 	if (b < 0)
54 		ub = -ub;
55 	(void)__qdivrem(ua, ub, &ur);
56 	if (neg)
57 		ur = -ur;
58 	return (ur);
59 }
60