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- #ifndef _ASM_X86_HWEIGHT_H
- #define _ASM_X86_HWEIGHT_H
- #ifdef CONFIG_64BIT
- /* popcnt %edi, %eax -- redundant REX prefix for alignment */
- #define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7"
- /* popcnt %rdi, %rax */
- #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7"
- #define REG_IN "D"
- #define REG_OUT "a"
- #else
- /* popcnt %eax, %eax */
- #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0"
- #define REG_IN "a"
- #define REG_OUT "a"
- #endif
- /*
- * __sw_hweightXX are called from within the alternatives below
- * and callee-clobbered registers need to be taken care of. See
- * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective
- * compiler switches.
- */
- static inline unsigned int __arch_hweight32(unsigned int w)
- {
- unsigned int res = 0;
- asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
- : "="REG_OUT (res)
- : REG_IN (w));
- return res;
- }
- static inline unsigned int __arch_hweight16(unsigned int w)
- {
- return __arch_hweight32(w & 0xffff);
- }
- static inline unsigned int __arch_hweight8(unsigned int w)
- {
- return __arch_hweight32(w & 0xff);
- }
- static inline unsigned long __arch_hweight64(__u64 w)
- {
- unsigned long res = 0;
- #ifdef CONFIG_X86_32
- return __arch_hweight32((u32)w) +
- __arch_hweight32((u32)(w >> 32));
- #else
- asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)
- : "="REG_OUT (res)
- : REG_IN (w));
- #endif /* CONFIG_X86_32 */
- return res;
- }
- #endif
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