d61931d89b
Add support for the hardware version of the Hamming weight function, popcnt, present in CPUs which advertize it under CPUID, Function 0x0000_0001_ECX[23]. On CPUs which don't support it, we fallback to the default lib/hweight.c sw versions. A synthetic benchmark comparing popcnt with __sw_hweight64 showed almost a 3x speedup on a F10h machine. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> LKML-Reference: <20100318112015.GC11152@aftab> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
26 lines
488 B
C
26 lines
488 B
C
#ifndef _ASM_GENERIC_BITOPS_ARCH_HWEIGHT_H_
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#define _ASM_GENERIC_BITOPS_ARCH_HWEIGHT_H_
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#include <asm/types.h>
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inline unsigned int __arch_hweight32(unsigned int w)
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{
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return __sw_hweight32(w);
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}
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inline unsigned int __arch_hweight16(unsigned int w)
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{
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return __sw_hweight16(w);
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}
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inline unsigned int __arch_hweight8(unsigned int w)
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{
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return __sw_hweight8(w);
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}
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inline unsigned long __arch_hweight64(__u64 w)
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{
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return __sw_hweight64(w);
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}
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#endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */
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