divmodhi3.c revision 1.1.1.10 
1/* Libgcc Target specific implementation - Emulating div and mod.
2   Copyright (C) 2012-2022 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
29unsigned short
30udivmodhi4 (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
56short
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
82short
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
105short
106__udivhi3 (short a, short b)
107{
108  return udivmodhi4 (a, b, 0);
109}
110
111short
112__umodhi3 (short a, short b)
113{
114  return udivmodhi4 (a, b, 1);
115}
116