arch/x86/include/asm/arch_hweight.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_HWEIGHT_H
   3 #define _ASM_X86_HWEIGHT_H
   4
   5 #include <asm/cpufeatures.h>
   6
   7 #ifdef CONFIG_64BIT
   8 /* popcnt %edi, %eax */
   9 #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc7"
  10 /* popcnt %rdi, %rax */
  11 #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7"
  12 #define REG_IN "D"
  13 #define REG_OUT "a"
  14 #else
  15 /* popcnt %eax, %eax */
  16 #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0"
  17 #define REG_IN "a"
  18 #define REG_OUT "a"
  19 #endif
  20
  21 #define __HAVE_ARCH_SW_HWEIGHT
  22
  23 static __always_inline unsigned int __arch_hweight32(unsigned int w)
  24 {
  25         unsigned int res;
  26
  27         asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
  28                          : "="REG_OUT (res)
  29                          : REG_IN (w));
  30
  31         return res;
  32 }
  33
  34 static inline unsigned int __arch_hweight16(unsigned int w)
  35 {
  36         return __arch_hweight32(w & 0xffff);
  37 }
  38
  39 static inline unsigned int __arch_hweight8(unsigned int w)
  40 {
  41         return __arch_hweight32(w & 0xff);
  42 }
  43
  44 #ifdef CONFIG_X86_32
  45 static inline unsigned long __arch_hweight64(__u64 w)
  46 {
  47         return  __arch_hweight32((u32)w) +
  48                 __arch_hweight32((u32)(w >> 32));
  49 }
  50 #else
  51 static __always_inline unsigned long __arch_hweight64(__u64 w)
  52 {
  53         unsigned long res;
  54
  55         asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)
  56                          : "="REG_OUT (res)
  57                          : REG_IN (w));
  58
  59         return res;
  60 }
  61 #endif /* CONFIG_X86_32 */
  62
  63 #endif