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
|
/* count-one-bits.h -- counts the number of 1-bits in a word.
Copyright (C) 2007-2017 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Ben Pfaff. */
#ifndef COUNT_ONE_BITS_H
#define COUNT_ONE_BITS_H 1
#include <limits.h>
#include <stdlib.h>
#ifndef _GL_INLINE_HEADER_BEGIN
#error "Please include config.h first."
#endif
_GL_INLINE_HEADER_BEGIN
#ifndef COUNT_ONE_BITS_INLINE
# define COUNT_ONE_BITS_INLINE _GL_INLINE
#endif
/* Expand to code that computes the number of 1-bits of the local
variable 'x' of type TYPE (an unsigned integer type) and return it
from the current function. */
#define COUNT_ONE_BITS_GENERIC(TYPE) \
do \
{ \
int count = 0; \
int bits; \
for (bits = 0; bits < sizeof (TYPE) * CHAR_BIT; bits += 32) \
{ \
count += count_one_bits_32 (x); \
x = x >> 31 >> 1; \
} \
return count; \
} \
while (0)
/* Assuming the GCC builtin is BUILTIN and the MSC builtin is MSC_BUILTIN,
expand to code that computes the number of 1-bits of the local
variable 'x' of type TYPE (an unsigned integer type) and return it
from the current function. */
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
# define COUNT_ONE_BITS(BUILTIN, MSC_BUILTIN, TYPE) return BUILTIN (x)
#else
/* Compute and return the number of 1-bits set in the least
significant 32 bits of X. */
COUNT_ONE_BITS_INLINE int
count_one_bits_32 (unsigned int x)
{
x = ((x & 0xaaaaaaaaU) >> 1) + (x & 0x55555555U);
x = ((x & 0xccccccccU) >> 2) + (x & 0x33333333U);
x = (x >> 16) + (x & 0xffff);
x = ((x & 0xf0f0) >> 4) + (x & 0x0f0f);
return (x >> 8) + (x & 0x00ff);
}
# if 1500 <= _MSC_VER && (defined _M_IX86 || defined _M_X64)
/* While gcc falls back to its own generic code if the machine
on which it's running doesn't support popcount, with Microsoft's
compiler we need to detect and fallback ourselves. */
# pragma intrinsic __cpuid
# pragma intrinsic __popcnt
# pragma intrinsic __popcnt64
/* Return nonzero if popcount is supported. */
/* 1 if supported, 0 if not supported, -1 if unknown. */
extern int popcount_support;
COUNT_ONE_BITS_INLINE int
popcount_supported (void)
{
if (popcount_support < 0)
{
int cpu_info[4];
__cpuid (cpu_info, 1);
popcount_support = (cpu_info[2] >> 23) & 1; /* See MSDN. */
}
return popcount_support;
}
# define COUNT_ONE_BITS(BUILTIN, MSC_BUILTIN, TYPE) \
do \
{ \
if (popcount_supported ()) \
return MSC_BUILTIN (x); \
else \
COUNT_ONE_BITS_GENERIC (TYPE); \
} \
while (0)
# else
# define COUNT_ONE_BITS(BUILTIN, MSC_BUILTIN, TYPE) \
COUNT_ONE_BITS_GENERIC (TYPE)
# endif
#endif
/* Compute and return the number of 1-bits set in X. */
COUNT_ONE_BITS_INLINE int
count_one_bits (unsigned int x)
{
COUNT_ONE_BITS (__builtin_popcount, __popcnt, unsigned int);
}
/* Compute and return the number of 1-bits set in X. */
COUNT_ONE_BITS_INLINE int
count_one_bits_l (unsigned long int x)
{
COUNT_ONE_BITS (__builtin_popcountl, __popcnt, unsigned long int);
}
#if HAVE_UNSIGNED_LONG_LONG_INT
/* Compute and return the number of 1-bits set in X. */
COUNT_ONE_BITS_INLINE int
count_one_bits_ll (unsigned long long int x)
{
COUNT_ONE_BITS (__builtin_popcountll, __popcnt64, unsigned long long int);
}
#endif
_GL_INLINE_HEADER_END
#endif /* COUNT_ONE_BITS_H */
|
