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1 | /* |
1 | /* |
2 | * Copyright (c) 2006 Josef Cejka |
2 | * Copyright (c) 2006 Josef Cejka |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
13 | * documentation and/or other materials provided with the distribution. |
14 | * - The name of the author may not be used to endorse or promote products |
14 | * - The name of the author may not be used to endorse or promote products |
15 | * derived from this software without specific prior written permission. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
29 | /** @addtogroup genarch |
29 | /** @addtogroup genarch |
30 | * @{ |
30 | * @{ |
31 | */ |
31 | */ |
32 | /** @file |
32 | /** @file |
33 | */ |
33 | */ |
34 | 34 | ||
35 | #include <genarch/softint/division.h> |
35 | #include <genarch/softint/division.h> |
36 | 36 | ||
37 | #define ABSVAL(x) ((x) > 0 ? (x) : -(x)) |
37 | #define ABSVAL(x) ((x) > 0 ? (x) : -(x)) |
38 | #define SGN(x) ((x) >= 0 ? 1 : 0) |
38 | #define SGN(x) ((x) >= 0 ? 1 : 0) |
39 | 39 | ||
40 | static unsigned int divandmod32(unsigned int a, unsigned int b, |
40 | static unsigned int divandmod32(unsigned int a, unsigned int b, |
41 | unsigned int *remainder) |
41 | unsigned int *remainder) |
42 | { |
42 | { |
43 | unsigned int result; |
43 | unsigned int result; |
44 | int steps = sizeof(unsigned int) * 8; |
44 | int steps = sizeof(unsigned int) * 8; |
45 | 45 | ||
46 | *remainder = 0; |
46 | *remainder = 0; |
47 | result = 0; |
47 | result = 0; |
48 | 48 | ||
49 | if (b == 0) { |
49 | if (b == 0) { |
50 | /* FIXME: division by zero */ |
50 | /* FIXME: division by zero */ |
51 | return 0; |
51 | return 0; |
52 | } |
52 | } |
53 | 53 | ||
54 | if (a < b) { |
54 | if (a < b) { |
55 | *remainder = a; |
55 | *remainder = a; |
56 | return 0; |
56 | return 0; |
57 | } |
57 | } |
58 | 58 | ||
59 | for (; steps > 0; steps--) { |
59 | for (; steps > 0; steps--) { |
60 | /* shift one bit to remainder */ |
60 | /* shift one bit to remainder */ |
61 | *remainder = ((*remainder) << 1) | (( a >> 31) & 0x1); |
61 | *remainder = ((*remainder) << 1) | (( a >> 31) & 0x1); |
62 | result <<= 1; |
62 | result <<= 1; |
63 | 63 | ||
64 | if (*remainder >= b) { |
64 | if (*remainder >= b) { |
65 | *remainder -= b; |
65 | *remainder -= b; |
66 | result |= 0x1; |
66 | result |= 0x1; |
67 | } |
67 | } |
68 | a <<= 1; |
68 | a <<= 1; |
69 | } |
69 | } |
70 | 70 | ||
71 | return result; |
71 | return result; |
72 | } |
72 | } |
73 | 73 | ||
74 | 74 | ||
75 | static unsigned long long divandmod64(unsigned long long a, |
75 | static unsigned long long divandmod64(unsigned long long a, |
76 | unsigned long long b, unsigned long long *remainder) |
76 | unsigned long long b, unsigned long long *remainder) |
77 | { |
77 | { |
78 | unsigned long long result; |
78 | unsigned long long result; |
79 | int steps = sizeof(unsigned long long) * 8; |
79 | int steps = sizeof(unsigned long long) * 8; |
80 | 80 | ||
81 | *remainder = 0; |
81 | *remainder = 0; |
82 | result = 0; |
82 | result = 0; |
83 | 83 | ||
84 | if (b == 0) { |
84 | if (b == 0) { |
85 | /* FIXME: division by zero */ |
85 | /* FIXME: division by zero */ |
86 | return 0; |
86 | return 0; |
87 | } |
87 | } |
88 | 88 | ||
89 | if (a < b) { |
89 | if (a < b) { |
90 | *remainder = a; |
90 | *remainder = a; |
91 | return 0; |
91 | return 0; |
92 | } |
92 | } |
93 | 93 | ||
94 | for (; steps > 0; steps--) { |
94 | for (; steps > 0; steps--) { |
95 | /* shift one bit to remainder */ |
95 | /* shift one bit to remainder */ |
96 | *remainder = ((*remainder) << 1) | ((a >> 63) & 0x1); |
96 | *remainder = ((*remainder) << 1) | ((a >> 63) & 0x1); |
97 | result <<= 1; |
97 | result <<= 1; |
98 | 98 | ||
99 | if (*remainder >= b) { |
99 | if (*remainder >= b) { |
100 | *remainder -= b; |
100 | *remainder -= b; |
101 | result |= 0x1; |
101 | result |= 0x1; |
102 | } |
102 | } |
103 | a <<= 1; |
103 | a <<= 1; |
104 | } |
104 | } |
105 | 105 | ||
106 | return result; |
106 | return result; |
107 | } |
107 | } |
108 | 108 | ||
109 | /* 32bit integer division */ |
109 | /* 32bit integer division */ |
110 | int __divsi3(int a, int b) |
110 | int __divsi3(int a, int b) |
111 | { |
111 | { |
112 | unsigned int rem; |
112 | unsigned int rem; |
113 | int result; |
113 | int result; |
114 | 114 | ||
115 | result = (int) divandmod32(ABSVAL(a), ABSVAL(b), &rem); |
115 | result = (int) divandmod32(ABSVAL(a), ABSVAL(b), &rem); |
116 | 116 | ||
117 | if (SGN(a) == SGN(b)) |
117 | if (SGN(a) == SGN(b)) |
118 | return result; |
118 | return result; |
119 | return -result; |
119 | return -result; |
120 | } |
120 | } |
121 | 121 | ||
122 | /* 64bit integer division */ |
122 | /* 64bit integer division */ |
123 | long long __divdi3(long long a, long long b) |
123 | long long __divdi3(long long a, long long b) |
124 | { |
124 | { |
125 | unsigned long long rem; |
125 | unsigned long long rem; |
126 | long long result; |
126 | long long result; |
127 | 127 | ||
128 | result = (long long) divandmod64(ABSVAL(a), ABSVAL(b), &rem); |
128 | result = (long long) divandmod64(ABSVAL(a), ABSVAL(b), &rem); |
129 | 129 | ||
130 | if (SGN(a) == SGN(b)) |
130 | if (SGN(a) == SGN(b)) |
131 | return result; |
131 | return result; |
132 | return -result; |
132 | return -result; |
133 | } |
133 | } |
134 | 134 | ||
135 | /* 32bit unsigned integer division */ |
135 | /* 32bit unsigned integer division */ |
136 | unsigned int __udivsi3(unsigned int a, unsigned int b) |
136 | unsigned int __udivsi3(unsigned int a, unsigned int b) |
137 | { |
137 | { |
138 | unsigned int rem; |
138 | unsigned int rem; |
139 | return divandmod32(a, b, &rem); |
139 | return divandmod32(a, b, &rem); |
140 | } |
140 | } |
141 | 141 | ||
142 | /* 64bit unsigned integer division */ |
142 | /* 64bit unsigned integer division */ |
143 | unsigned long long __udivdi3(unsigned long long a, unsigned long long b) |
143 | unsigned long long __udivdi3(unsigned long long a, unsigned long long b) |
144 | { |
144 | { |
145 | unsigned long long rem; |
145 | unsigned long long rem; |
146 | return divandmod64(a, b, &rem); |
146 | return divandmod64(a, b, &rem); |
147 | } |
147 | } |
148 | 148 | ||
149 | /* 32bit remainder of the signed division */ |
149 | /* 32bit remainder of the signed division */ |
150 | int __modsi3(int a, int b) |
150 | int __modsi3(int a, int b) |
151 | { |
151 | { |
152 | unsigned int rem; |
152 | unsigned int rem; |
153 | divandmod32(a, b, &rem); |
153 | divandmod32(a, b, &rem); |
154 | 154 | ||
155 | /* if divident is negative, remainder must be too */ |
155 | /* if divident is negative, remainder must be too */ |
156 | if (!(SGN(a))) { |
156 | if (!(SGN(a))) { |
157 | return -((int) rem); |
157 | return -((int) rem); |
158 | } |
158 | } |
159 | 159 | ||
160 | return (int) rem; |
160 | return (int) rem; |
161 | } |
161 | } |
162 | 162 | ||
163 | /* 64bit remainder of the signed division */ |
163 | /* 64bit remainder of the signed division */ |
164 | long long __moddi3(long long a,long long b) |
164 | long long __moddi3(long long a,long long b) |
165 | { |
165 | { |
166 | unsigned long long rem; |
166 | unsigned long long rem; |
167 | divandmod64(a, b, &rem); |
167 | divandmod64(a, b, &rem); |
168 | 168 | ||
169 | /* if divident is negative, remainder must be too */ |
169 | /* if divident is negative, remainder must be too */ |
170 | if (!(SGN(a))) { |
170 | if (!(SGN(a))) { |
171 | return -((long long) rem); |
171 | return -((long long) rem); |
172 | } |
172 | } |
173 | 173 | ||
174 | return (long long) rem; |
174 | return (long long) rem; |
175 | } |
175 | } |
176 | 176 | ||
177 | /* 32bit remainder of the unsigned division */ |
177 | /* 32bit remainder of the unsigned division */ |
178 | unsigned int __umodsi3(unsigned int a, unsigned int b) |
178 | unsigned int __umodsi3(unsigned int a, unsigned int b) |
179 | { |
179 | { |
180 | unsigned int rem; |
180 | unsigned int rem; |
181 | divandmod32(a, b, &rem); |
181 | divandmod32(a, b, &rem); |
182 | return rem; |
182 | return rem; |
183 | } |
183 | } |
184 | 184 | ||
185 | /* 64bit remainder of the unsigned division */ |
185 | /* 64bit remainder of the unsigned division */ |
186 | unsigned long long __umoddi3(unsigned long long a, unsigned long long b) |
186 | unsigned long long __umoddi3(unsigned long long a, unsigned long long b) |
187 | { |
187 | { |
188 | unsigned long long rem; |
188 | unsigned long long rem; |
189 | divandmod64(a, b, &rem); |
189 | divandmod64(a, b, &rem); |
190 | return rem; |
190 | return rem; |
191 | } |
191 | } |
192 | 192 | ||
193 | unsigned long long __udivmoddi3(unsigned long long a, unsigned long long b, |
193 | unsigned long long __udivmoddi3(unsigned long long a, unsigned long long b, |
194 | unsigned long long *c) |
194 | unsigned long long *c) |
195 | { |
195 | { |
196 | return divandmod64(a, b, c); |
196 | return divandmod64(a, b, c); |
197 | } |
197 | } |
198 | 198 | ||
199 | /** @} |
199 | /** @} |
200 | */ |
200 | */ |
201 | 201 |