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| author | Alexander van Heukelum <heukelum@mailshack.com> | 2008-03-15 13:04:42 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-26 19:21:16 +0200 |
| commit | 12d9c8420b9daa1da3d9e090640fb24bcd0deba2 (patch) | |
| tree | 60affb5bdc5b857dfb3969234659caedbf2ff02a /arch | |
| parent | x86, generic: optimize find_next_(zero_)bit for small constant-size bitmaps (diff) | |
| download | linux-12d9c8420b9daa1da3d9e090640fb24bcd0deba2.tar.xz linux-12d9c8420b9daa1da3d9e090640fb24bcd0deba2.zip | |
x86: merge the simple bitops and move them to bitops.h
Some of those can be written in such a way that the same
inline assembly can be used to generate both 32 bit and
64 bit code.
For ffs and fls, x86_64 unconditionally used the cmov
instruction and i386 unconditionally used a conditional
branch over a mov instruction. In the current patch I
chose to select the version based on the availability
of the cmov instruction instead. A small detail here is
that x86_64 did not previously set CONFIG_X86_CMOV=y.
Improved comments for ffs, ffz, fls and variations.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/Kconfig.cpu | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index 4da3cdb9c1b1..cf3ff2c5cef2 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -398,7 +398,7 @@ config X86_TSC # generates cmov. config X86_CMOV def_bool y - depends on (MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7) + depends on (MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7 || X86_64) config X86_MINIMUM_CPU_FAMILY int |