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
|
/***************************************************************************************************
* Copyright (c) 2017-2018, NVIDIA CORPORATION. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
* * Neither the name of the NVIDIA CORPORATION nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TOR (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
**************************************************************************************************/
#pragma once
/**
* \file
* \brief Math utilities
*/
#include <cutlass/util/platform.h>
namespace cutlass {
/******************************************************************************
* Static math utilities
******************************************************************************/
/**
* Statically determine if N is a power-of-two
*/
template <int N>
struct is_pow2 : platform::integral_constant<bool, (N & (N - 1)) == 0> {};
/**
* Statically determine log2(N), rounded down
*/
template <int N, int CurrentVal = N, int Count = 0>
struct log2_down {
/// Static logarithm value
enum { value = log2_down<N, (CurrentVal >> 1), Count + 1>::value };
};
// Base case
template <int N, int Count>
struct log2_down<N, 1, Count> {
enum { value = Count };
};
/**
* Statically determine log2(N), rounded up
*/
template <int N, int CurrentVal = N, int Count = 0>
struct log2_up {
/// Static logarithm value
enum { value = log2_up<N, (CurrentVal >> 1), Count + 1>::value };
};
// Base case
template <int N, int Count>
struct log2_up<N, 1, Count> {
enum { value = ((1 << Count) < N) ? Count + 1 : Count };
};
/**
* Statically estimate sqrt(N) to the nearest power-of-two
*/
template <int N>
struct sqrt_est {
enum { value = 1 << (log2_up<N>::value / 2) };
};
/**
* For performing a constant-division with a compile-time assertion that the
* Divisor evenly-divides the Dividend.
*/
template <int Dividend, int Divisor>
struct divide_assert {
enum { value = Dividend / Divisor };
static_assert((Dividend % Divisor == 0), "Not an even multiple");
};
/******************************************************************************
* Rounding
******************************************************************************/
/**
* Round dividend up to the nearest multiple of divisor
*/
template <typename dividend_t, typename divisor_t>
CUTLASS_HOST_DEVICE dividend_t round_nearest(dividend_t dividend, divisor_t divisor) {
return ((dividend + divisor - 1) / divisor) * divisor;
}
/**
* Greatest common divisor
*/
template <typename value_t>
CUTLASS_HOST_DEVICE value_t gcd(value_t a, value_t b) {
for (;;) {
if (a == 0) return b;
b %= a;
if (b == 0) return a;
a %= b;
}
}
/**
* Least common multiple
*/
template <typename value_t>
CUTLASS_HOST_DEVICE value_t lcm(value_t a, value_t b) {
value_t temp = gcd(a, b);
return temp ? (a / temp * b) : 0;
}
} // namespace cutlass
|
