kolibrios/drivers/include/asm-generic/bitops/const_hweight.h
Sergey Semyonov (Serge) 16bc56fa96 ddk: 3.19-rc1
git-svn-id: svn://kolibrios.org@5270 a494cfbc-eb01-0410-851d-a64ba20cac60
2014-12-27 15:42:08 +00:00

44 lines
1.6 KiB
C

#ifndef _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
#define _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
/*
* Compile time versions of __arch_hweightN()
*/
#define __const_hweight8(w) \
((unsigned int) \
((!!((w) & (1ULL << 0))) + \
(!!((w) & (1ULL << 1))) + \
(!!((w) & (1ULL << 2))) + \
(!!((w) & (1ULL << 3))) + \
(!!((w) & (1ULL << 4))) + \
(!!((w) & (1ULL << 5))) + \
(!!((w) & (1ULL << 6))) + \
(!!((w) & (1ULL << 7)))))
#define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 ))
#define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16))
#define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32))
/*
* Generic interface.
*/
#define hweight8(w) (__builtin_constant_p(w) ? __const_hweight8(w) : __arch_hweight8(w))
#define hweight16(w) (__builtin_constant_p(w) ? __const_hweight16(w) : __arch_hweight16(w))
#define hweight32(w) (__builtin_constant_p(w) ? __const_hweight32(w) : __arch_hweight32(w))
#define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w))
/*
* Interface for known constant arguments
*/
#define HWEIGHT8(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight8(w))
#define HWEIGHT16(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight16(w))
#define HWEIGHT32(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight32(w))
#define HWEIGHT64(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight64(w))
/*
* Type invariant interface to the compile time constant hweight functions.
*/
#define HWEIGHT(w) HWEIGHT64((u64)w)
#endif /* _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ */