LXR linux/include/asm-generic/bitops/const

   1#ifndef _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
   2#define _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
   3
   4/*
   5 * Compile time versions of __arch_hweightN()
   6 */
   7#define __const_hweight8(w)             \
   8      ( (!!((w) & (1ULL << 0))) +       \
   9        (!!((w) & (1ULL << 1))) +       \
  10        (!!((w) & (1ULL << 2))) +       \
  11        (!!((w) & (1ULL << 3))) +       \
  12        (!!((w) & (1ULL << 4))) +       \
  13        (!!((w) & (1ULL << 5))) +       \
  14        (!!((w) & (1ULL << 6))) +       \
  15        (!!((w) & (1ULL << 7))) )
  16
  17#define __const_hweight16(w) (__const_hweight8(w)  + __const_hweight8((w)  >> 8 ))
  18#define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16))
  19#define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32))
  20
  21/*
  22 * Generic interface.
  23 */
  24#define hweight8(w)  (__builtin_constant_p(w) ? __const_hweight8(w)  : __arch_hweight8(w))
  25#define hweight16(w) (__builtin_constant_p(w) ? __const_hweight16(w) : __arch_hweight16(w))
  26#define hweight32(w) (__builtin_constant_p(w) ? __const_hweight32(w) : __arch_hweight32(w))
  27#define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w))
  28
  29/*
  30 * Interface for known constant arguments
  31 */
  32#define HWEIGHT8(w)  (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight8(w))
  33#define HWEIGHT16(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight16(w))
  34#define HWEIGHT32(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight32(w))
  35#define HWEIGHT64(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight64(w))
  36
  37/*
  38 * Type invariant interface to the compile time constant hweight functions.
  39 */
  40#define HWEIGHT(w)   HWEIGHT64((u64)w)
  41
  42#endif /* _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ */
  43