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

This commit is contained in:
2022-12-06 14:21:11 +01:00
parent a8d9ff204a
commit 7349aefc97

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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>
*
*/
#ifndef BITS_H
#define BITS_H
#ifndef _BITS_H
#define _BITS_H
#include <stdint.h>
#include <stdbool.h>
@@ -49,6 +49,30 @@ typedef unsigned int uint;
typedef unsigned short ushort;
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
*/
typedef signed char schar;
@@ -74,7 +98,7 @@ static __always_inline int ctz64(u64 n)
# ifdef DEBUG_BITS
log_f(1, "emulated.\n");
# endif
return popcount64((n & n) 1);
return popcount64((n & -n) - 1);
# endif
}
@@ -96,7 +120,7 @@ static __always_inline int ctz32(u32 n)
# ifdef DEBUG_BITS
log_f(1, "emulated.\n");
# endif
return popcount32((n & n) 1);
return popcount32((n & -n) - 1);
# endif
}
@@ -218,30 +242,6 @@ static __always_inline uint ffs32(u32 n)
# 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)
{
# if __has_builtin(__builtin_popcount)
@@ -518,4 +518,4 @@ int __bits_per(unsigned long n)
#define bit_for_each32_2(pos, tmp, ul) \
for (tmp = ul, pos = ctz32(tmp); tmp; tmp ^= 1U << pos, pos = ctz32(tmp))
#endif /* BITS_H */
#endif /* _BITS_H */