LXR linux/arch/x86/include/asm/arch

   1#ifndef _ASM_X86_HWEIGHT_H
   2#define _ASM_X86_HWEIGHT_H
   3
   4#include <asm/cpufeatures.h>
   5
   6#ifdef CONFIG_64BIT
   7/* popcnt %edi, %eax */
   8#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc7"
   9/* popcnt %rdi, %rax */
  10#define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7"
  11#define REG_IN "D"
  12#define REG_OUT "a"
  13#else
  14/* popcnt %eax, %eax */
  15#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0"
  16#define REG_IN "a"
  17#define REG_OUT "a"
  18#endif
  19
  20#define __HAVE_ARCH_SW_HWEIGHT
  21
  22static __always_inline unsigned int __arch_hweight32(unsigned int w)
  23{
  24        unsigned int res;
  25
  26        asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
  27                         : "="REG_OUT (res)
  28                         : REG_IN (w));
  29
  30        return res;
  31}
  32
  33static inline unsigned int __arch_hweight16(unsigned int w)
  34{
  35        return __arch_hweight32(w & 0xffff);
  36}
  37
  38static inline unsigned int __arch_hweight8(unsigned int w)
  39{
  40        return __arch_hweight32(w & 0xff);
  41}
  42
  43#ifdef CONFIG_X86_32
  44static inline unsigned long __arch_hweight64(__u64 w)
  45{
  46        return  __arch_hweight32((u32)w) +
  47                __arch_hweight32((u32)(w >> 32));
  48}
  49#else
  50static __always_inline unsigned long __arch_hweight64(__u64 w)
  51{
  52        unsigned long res;
  53
  54        asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)
  55                         : "="REG_OUT (res)
  56                         : REG_IN (w));
  57
  58        return res;
  59}
  60#endif /* CONFIG_X86_32 */
  61
  62#endif
  63