From d61931d89be506372d01a90d1755f6d0a9fafe2d Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 5 Mar 2010 17:34:46 +0100 Subject: x86: Add optimized popcnt variants 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 LKML-Reference: <20100318112015.GC11152@aftab> Signed-off-by: H. Peter Anvin --- include/asm-generic/bitops/arch_hweight.h | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'include/asm-generic/bitops') diff --git a/include/asm-generic/bitops/arch_hweight.h b/include/asm-generic/bitops/arch_hweight.h index 3a7be84..9a81c1e 100644 --- a/include/asm-generic/bitops/arch_hweight.h +++ b/include/asm-generic/bitops/arch_hweight.h @@ -3,9 +3,23 @@ #include -extern unsigned int __arch_hweight32(unsigned int w); -extern unsigned int __arch_hweight16(unsigned int w); -extern unsigned int __arch_hweight8(unsigned int w); -extern unsigned long __arch_hweight64(__u64 w); +inline unsigned int __arch_hweight32(unsigned int w) +{ + return __sw_hweight32(w); +} +inline unsigned int __arch_hweight16(unsigned int w) +{ + return __sw_hweight16(w); +} + +inline unsigned int __arch_hweight8(unsigned int w) +{ + return __sw_hweight8(w); +} + +inline unsigned long __arch_hweight64(__u64 w) +{ + return __sw_hweight64(w); +} #endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */ -- cgit v1.1