arch/x86/include/asm/arch_hweight.h

   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
  22 static __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
  33 static inline unsigned int __arch_hweight16(unsigned int w)
  34 {
  35         return __arch_hweight32(w & 0xffff);
  36 }
  37
  38 static inline unsigned int __arch_hweight8(unsigned int w)
  39 {
  40         return __arch_hweight32(w & 0xff);
  41 }
  42
  43 #ifdef CONFIG_X86_32
  44 static inline unsigned long __arch_hweight64(__u64 w)
  45 {
  46         return  __arch_hweight32((u32)w) +
  47                 __arch_hweight32((u32)(w >> 32));
  48 }
  49 #else
  50 static __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