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bits.h: move popcount up, fix erroneous japanese '−' instead of '-' (minus)

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Bruno Raoult
2022-12-06 14:21:11 +01:00
parent a8d9ff204a
commit 7349aefc97
1 changed files with 29 additions and 29 deletions
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58
c/include/bits.h
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@@ -10,8 +10,8 @@
* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html> * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
* *
*/ */
#ifndef BITS_H #ifndef _BITS_H
#define BITS_H #define _BITS_H
#include <stdint.h> #include <stdint.h>
#include <stdbool.h> #include <stdbool.h>
@@ -49,6 +49,30 @@ typedef unsigned int uint;
typedef unsigned short ushort; typedef unsigned short ushort;
typedef unsigned char uchar; typedef unsigned char uchar;
/* count set bits: 10101000 -> 3
* ^ ^ ^
*/
static __always_inline int popcount64(u64 n)
{
# if __has_builtin(__builtin_popcountl)
# ifdef DEBUG_BITS
log_f(1, "builtin.\n");
# endif
return __builtin_popcountl(n);
# else
# ifdef DEBUG_BITS
log_f(1, "emulated.\n");
# endif
int count = 0;
while (n) {
count++;
n &= (n - 1);
}
return count;
# endif
}
/* char is a special case, as it can be signed or unsigned /* char is a special case, as it can be signed or unsigned
*/ */
typedef signed char schar; typedef signed char schar;
@@ -74,7 +98,7 @@ static __always_inline int ctz64(u64 n)
# ifdef DEBUG_BITS # ifdef DEBUG_BITS
log_f(1, "emulated.\n"); log_f(1, "emulated.\n");
# endif # endif
return popcount64((n & −n) − 1); return popcount64((n & -n) - 1);
# endif # endif
} }
@@ -96,7 +120,7 @@ static __always_inline int ctz32(u32 n)
# ifdef DEBUG_BITS # ifdef DEBUG_BITS
log_f(1, "emulated.\n"); log_f(1, "emulated.\n");
# endif # endif
return popcount32((n & −n) − 1); return popcount32((n & -n) - 1);
# endif # endif
} }
@@ -218,30 +242,6 @@ static __always_inline uint ffs32(u32 n)
# endif # endif
} }
/* count set bits: 10101000 -> 3
* ^ ^ ^
*/
static __always_inline int popcount64(u64 n)
{
# if __has_builtin(__builtin_popcountl)
# ifdef DEBUG_BITS
log_f(1, "builtin.\n");
# endif
return __builtin_popcountl(n);
# else
# ifdef DEBUG_BITS
log_f(1, "emulated.\n");
# endif
int count = 0;
while (n) {
count++;
n &= (n - 1);
}
return count;
# endif
}
static __always_inline int popcount32(u32 n) static __always_inline int popcount32(u32 n)
{ {
# if __has_builtin(__builtin_popcount) # if __has_builtin(__builtin_popcount)
@@ -518,4 +518,4 @@ int __bits_per(unsigned long n)
#define bit_for_each32_2(pos, tmp, ul) \ #define bit_for_each32_2(pos, tmp, ul) \
for (tmp = ul, pos = ctz32(tmp); tmp; tmp ^= 1U << pos, pos = ctz32(tmp)) for (tmp = ul, pos = ctz32(tmp); tmp; tmp ^= 1U << pos, pos = ctz32(tmp))
#endif /* BITS_H */ #endif /* _BITS_H */