1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
#ifndef AWS_COMMON_MATH_MSVC_INL
#define AWS_COMMON_MATH_MSVC_INL
/**
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0.
*/
/*
* This header is already included, but include it again to make editor
* highlighting happier.
*/
#include <aws/common/common.h>
#include <aws/common/math.h>
#include <immintrin.h>
#include <intrin.h>
AWS_EXTERN_C_BEGIN
/**
* Multiplies a * b. If the result overflows, returns 2^64 - 1.
*/
AWS_STATIC_IMPL uint64_t aws_mul_u64_saturating(uint64_t a, uint64_t b) {
uint64_t out;
uint64_t ret_val = _umul128(a, b, &out);
return (out == 0) ? ret_val : UINT64_MAX;
}
/**
* If a * b overflows, returns AWS_OP_ERR; otherwise multiplies
* a * b, returns the result in *r, and returns AWS_OP_SUCCESS.
*/
AWS_STATIC_IMPL int aws_mul_u64_checked(uint64_t a, uint64_t b, uint64_t *r) {
uint64_t out;
*r = _umul128(a, b, &out);
if (out != 0) {
return aws_raise_error(AWS_ERROR_OVERFLOW_DETECTED);
}
return AWS_OP_SUCCESS;
}
/**
* Multiplies a * b. If the result overflows, returns 2^32 - 1.
*/
AWS_STATIC_IMPL uint32_t aws_mul_u32_saturating(uint32_t a, uint32_t b) {
uint32_t out;
uint32_t ret_val = _mulx_u32(a, b, &out);
return (out == 0) ? ret_val : UINT32_MAX;
}
/**
* If a * b overflows, returns AWS_OP_ERR; otherwise multiplies
* a * b, returns the result in *r, and returns AWS_OP_SUCCESS.
*/
AWS_STATIC_IMPL int aws_mul_u32_checked(uint32_t a, uint32_t b, uint32_t *r) {
uint32_t out;
*r = _mulx_u32(a, b, &out);
if (out != 0) {
return aws_raise_error(AWS_ERROR_OVERFLOW_DETECTED);
}
return AWS_OP_SUCCESS;
}
/**
* If a + b overflows, returns AWS_OP_ERR; otherwise adds
* a + b, returns the result in *r, and returns AWS_OP_SUCCESS.
*/
AWS_STATIC_IMPL int aws_add_u64_checked(uint32_t a, uint32_t b, uint32_t *r) {
if (_addcarry_u64(0, a, b, *r)) {
return aws_raise_error(AWS_ERROR_OVERFLOW_DETECTED);
}
return AWS_OP_SUCCESS;
}
/**
* Adds a + b. If the result overflows, returns 2^64 - 1.
*/
AWS_STATIC_IMPL uint64_t aws_add_u64_saturating(uint32_t a, uint32_t b) {
uint32_t res;
if (_addcarry_u64(0, a, b, &res)) {
res = UINT64_MAX;
}
return res;
}
/**
* If a + b overflows, returns AWS_OP_ERR; otherwise adds
* a + b, returns the result in *r, and returns AWS_OP_SUCCESS.
*/
AWS_STATIC_IMPL int aws_add_u32_checked(uint32_t a, uint32_t b, uint32_t *r) {
if(_addcarry_u32(0, a, b, *r){
return aws_raise_error(AWS_ERROR_OVERFLOW_DETECTED);
}
return AWS_OP_SUCCESS;
}
/**
* Adds a + b. If the result overflows, returns 2^32 - 1.
*/
AWS_STATIC_IMPL uint64_t aws_add_u32_saturating(uint32_t a, uint32_t b) {
uint32_t res;
if (_addcarry_u32(0, a, b, &res)) {
res = UINT32_MAX;
}
return res;
}
/**
* Search from the MSB to LSB, looking for a 1
*/
AWS_STATIC_IMPL size_t aws_clz_u32(uint32_t n) {
unsigned long idx = 0;
_BitScanReverse(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_clz_i32(int32_t n) {
unsigned long idx = 0;
_BitScanReverse(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_clz_u64(uint64_t n) {
unsigned long idx = 0;
_BitScanReverse64(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_clz_i64(int64_t n) {
unsigned long idx = 0;
_BitScanReverse64(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_clz_size(size_t n) {
#if SIZE_BITS == 64
return aws_clz_u64(n);
#else
return aws_clz_u32(n);
#endif
}
/**
* Search from the LSB to MSB, looking for a 1
*/
AWS_STATIC_IMPL size_t aws_ctz_u32(uint32_t n) {
unsigned long idx = 0;
_BitScanForward(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_ctz_i32(int32_t n) {
unsigned long idx = 0;
_BitScanForward(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_ctz_u64(uint64_t n) {
unsigned long idx = 0;
_BitScanForward64(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_ctz_i64(int64_t n) {
unsigned long idx = 0;
_BitScanForward64(&idx, n);
return idx;
}
AWS_STATIC_IMPL size_t aws_ctz_size(size_t n) {
#if SIZE_BITS == 64
return aws_ctz_u64(n);
#else
return aws_ctz_u32(n);
#endif
}
AWS_EXTERN_C_END
#endif /* WS_COMMON_MATH_MSVC_INL */
|
