diff options
| author | Borislav Petkov <borislav.petkov@amd.com> | 2010-03-05 11:34:46 -0500 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-04-06 18:52:11 -0400 |
| commit | d61931d89be506372d01a90d1755f6d0a9fafe2d (patch) | |
| tree | 652c34238edcb6c558163abc3cd9d6ce7c5f91a5 /scripts | |
| 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 'scripts')
| -rw-r--r-- | scripts/Makefile.lib | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index f9bdf264473d..cbcd654215e6 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib | |||
| @@ -245,3 +245,7 @@ quiet_cmd_lzo = LZO $@ | |||
| 245 | cmd_lzo = (cat $(filter-out FORCE,$^) | \ | 245 | cmd_lzo = (cat $(filter-out FORCE,$^) | \ |
| 246 | lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ | 246 | lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ |
| 247 | (rm -f $@ ; false) | 247 | (rm -f $@ ; false) |
| 248 | |||
| 249 | # misc stuff | ||
| 250 | # --------------------------------------------------------------------------- | ||
| 251 | quote:=" | ||