diff options
| author | Borislav Petkov <borislav.petkov@amd.com> | 2010-03-05 17:34:46 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-04-06 15:52:11 -0700 |
| commit | d61931d89be506372d01a90d1755f6d0a9fafe2d (patch) | |
| tree | 652c34238edcb6c558163abc3cd9d6ce7c5f91a5 /arch/x86/include/asm/bitops.h | |
| parent | 1527bc8b928dd1399c3d3467dd47d9ede210978a (diff) | |
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 <borislav.petkov@amd.com>
LKML-Reference: <20100318112015.GC11152@aftab>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/bitops.h')
| -rw-r--r-- | arch/x86/include/asm/bitops.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 02b47a603fc..545776efeb1 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -444,7 +444,9 @@ static inline int fls(int x) #define ARCH_HAS_FAST_MULTIPLIER 1 -#include <asm-generic/bitops/hweight.h> +#include <asm/arch_hweight.h> + +#include <asm-generic/bitops/const_hweight.h> #endif /* __KERNEL__ */ |