1 /* $NetBSD: divsir.c,v 1.5 2012/02/04 17:03:09 skrll Exp $ */
2
3 /* $OpenBSD: divsir.c,v 1.5 2001/03/29 03:58:18 mickey Exp $ */
4
5 /*
6 * Copyright 1996 1995 by Open Software Foundation, Inc.
7 * All Rights Reserved
8 *
9 * Permission to use, copy, modify, and distribute this software and
10 * its documentation for any purpose and without fee is hereby granted,
11 * provided that the above copyright notice appears in all copies and
12 * that both the copyright notice and this permission notice appear in
13 * supporting documentation.
14 *
15 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
16 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
17 * FOR A PARTICULAR PURPOSE.
18 *
19 * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
20 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
21 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
22 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
23 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
24 *
25 */
26 /*
27 * pmk1.1
28 */
29 /*
30 * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
31 *
32 * To anyone who acknowledges that this file is provided "AS IS"
33 * without any express or implied warranty:
34 * permission to use, copy, modify, and distribute this file
35 * for any purpose is hereby granted without fee, provided that
36 * the above copyright notice and this notice appears in all
37 * copies, and that the name of Hewlett-Packard Company not be
38 * used in advertising or publicity pertaining to distribution
39 * of the software without specific, written prior permission.
40 * Hewlett-Packard Company makes no representations about the
41 * suitability of this software for any purpose.
42 */
43
44 #include <sys/cdefs.h>
45 __KERNEL_RCSID(0, "$NetBSD: divsir.c,v 1.5 2012/02/04 17:03:09 skrll Exp $");
46
47 #include "md.h"
48
49 void
divsir(int opnd1,int opnd2,struct mdsfu_register * result)50 divsir(int opnd1, int opnd2, struct mdsfu_register *result)
51 {
52 int sign, op1_sign;
53
54 /* check divisor for zero */
55 if (opnd2 == 0) {
56 overflow = true;
57 return;
58 }
59
60 /* get sign of result */
61 sign = opnd1 ^ opnd2;
62
63 /* get absolute value of operands */
64 if (opnd1 < 0) {
65 opnd1 = -opnd1;
66 op1_sign = true;
67 }
68 else op1_sign = false;
69 if (opnd2 < 0) opnd2 = -opnd2;
70
71 /* check for opnd2 = -2**31 */
72 if (opnd2 + opnd2 == 0) {
73 if (opnd1 == opnd2) {
74 result_hi = 0; /* remainder = 0 */
75 result_lo = 1;
76 }
77 else {
78 result_hi = opnd1; /* remainder = opnd1 */
79 result_lo = 0;
80 }
81 }
82 else {
83 /* do the divide */
84 divu(0,opnd1,opnd2,result);
85
86 /*
87 * check for overflow
88 *
89 * at this point, the only way we can get overflow
90 * is with opnd1 = -2**31 and opnd2 = -1
91 */
92 if (sign>0 && result_lo<0) {
93 overflow = true;
94 return;
95 }
96 }
97 overflow = false;
98
99 /* return appropriately signed remainder and result */
100 if (op1_sign) result_hi = -result_hi;
101 if (sign<0) result_lo = -result_lo;
102 return;
103 }
104