#ifndef _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
  #define _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
  
  /*
   * Compile time versions of __arch_hweightN()
   */
  #define __const_hweight8(w)		\
        (	(!!((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_ */