Line data    Source code

       1             : #ifndef _ASM_X86_HWEIGHT_H
       2             : #define _ASM_X86_HWEIGHT_H
       3             : 
       4             : #ifdef CONFIG_64BIT
       5             : /* popcnt %edi, %eax -- redundant REX prefix for alignment */
       6             : #define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7"
       7             : /* popcnt %rdi, %rax */
       8             : #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7"
       9             : #define REG_IN "D"
      10             : #define REG_OUT "a"
      11             : #else
      12             : /* popcnt %eax, %eax */
      13             : #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0"
      14             : #define REG_IN "a"
      15             : #define REG_OUT "a"
      16             : #endif
      17             : 
      18             : /*
      19             :  * __sw_hweightXX are called from within the alternatives below
      20             :  * and callee-clobbered registers need to be taken care of. See
      21             :  * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective
      22             :  * compiler switches.
      23             :  */
      24             : static inline unsigned int __arch_hweight32(unsigned int w)
      25             : {
      26             :         unsigned int res = 0;
      27             : 
      28             :         asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
      29             :                      : "="REG_OUT (res)
      30             :                      : REG_IN (w));
      31             : 
      32             :         return res;
      33             : }
      34             : 
      35             : static inline unsigned int __arch_hweight16(unsigned int w)
      36             : {
      37             :         return __arch_hweight32(w & 0xffff);
      38             : }
      39             : 
      40             : static inline unsigned int __arch_hweight8(unsigned int w)
      41             : {
      42             :         return __arch_hweight32(w & 0xff);
      43             : }
      44             : 
      45        2947 : static inline unsigned long __arch_hweight64(__u64 w)
      46             : {
      47             :         unsigned long res = 0;
      48             : 
      49             : #ifdef CONFIG_X86_32
      50             :         return  __arch_hweight32((u32)w) +
      51             :                 __arch_hweight32((u32)(w >> 32));
      52             : #else
      53        2947 :         asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)
      54             :                      : "="REG_OUT (res)
      55             :                      : REG_IN (w));
      56             : #endif /* CONFIG_X86_32 */
      57             : 
      58        2947 :         return res;
      59             : }
      60             : 
      61             : #endif