1 /* Libgcc Target specific implementation - Emulating div and mod.
2 Copyright (C) 2012-2020 Free Software Foundation, Inc.
3 Contributed by KPIT Cummins Infosystems Limited.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
15 License for more details.
16
17 Under Section 7 of GPL version 3, you are granted additional
18 permissions described in the GCC Runtime Library Exception, version
19 3.1, as published by the Free Software Foundation.
20
21 You should have received a copy of the GNU General Public License and
22 a copy of the GCC Runtime Library Exception along with this program;
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 <http://www.gnu.org/licenses/>. */
25
26
27 /* Emulate the division and modulus operation. */
28
29 unsigned short
udivmodhi4(unsigned short num,unsigned short den,short modwanted)30 udivmodhi4 (unsigned short num, unsigned short den, short modwanted)
31 {
32 unsigned short bit = 1;
33 unsigned short res = 0;
34
35 while (den < num && bit && !(den & (1 << 15)))
36 {
37 den <<= 1;
38 bit <<= 1;
39 }
40 while (bit)
41 {
42 if (num >= den)
43 {
44 num -= den;
45 res |= bit;
46 }
47 bit >>= 1;
48 den >>= 1;
49 }
50
51 if (modwanted)
52 return num;
53 return res;
54 }
55
56 short
__divhi3(short a,short b)57 __divhi3 (short a, short b)
58 {
59 short neg = 0;
60 short res;
61
62 if (a < 0)
63 {
64 a = -a;
65 neg = !neg;
66 }
67
68 if (b < 0)
69 {
70 b = -b;
71 neg = !neg;
72 }
73
74 res = udivmodhi4 (a, b, 0);
75
76 if (neg)
77 res = -res;
78
79 return res;
80 }
81
82 short
__modhi3(short a,short b)83 __modhi3 (short a, short b)
84 {
85 short neg = 0;
86 short res;
87
88 if (a < 0)
89 {
90 a = -a;
91 neg = 1;
92 }
93
94 if (b < 0)
95 b = -b;
96
97 res = udivmodhi4 (a, b, 1);
98
99 if (neg)
100 res = -res;
101
102 return res;
103 }
104
105 short
__udivhi3(short a,short b)106 __udivhi3 (short a, short b)
107 {
108 return udivmodhi4 (a, b, 0);
109 }
110
111 short
__umodhi3(short a,short b)112 __umodhi3 (short a, short b)
113 {
114 return udivmodhi4 (a, b, 1);
115 }
116