diff options
| author | David Woodhouse <dwmw2@infradead.org> | 2012-12-19 19:14:17 +0400 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-01-10 10:00:54 +0400 |
| commit | fe3955cb297290b0d5dedf5d2694a7cef455010e (patch) | |
| tree | 8901f2f72857d3490c1dda22dcdc3b2d7ccef326 /arch/powerpc/Kconfig | |
| parent | e49f1e203f3a66dd2982bcd8695e6f4a4f89f876 (diff) | |
| download | linux-fe3955cb297290b0d5dedf5d2694a7cef455010e.tar.xz | |
powerpc: Enable ARCH_USE_BUILTIN_BSWAP
By using the compiler intrinsics instead of hand-crafted opaque inline
assembler for byte-swapping, we let the compiler see what's actually
happening and it gets to use lwbrx/stwbrx instructions instead of a
normal load/store coupled with a sequence of rlwimi instructions to
move bits around.
Compiled-tested only. It gave a code size reduction of almost 4% for
ext2, and more like 2.5% for ext3/ext4.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/Kconfig')
| -rw-r--r-- | arch/powerpc/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 17903f1f356b..684fa6456797 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -144,6 +144,7 @@ config PPC select HAVE_MOD_ARCH_SPECIFIC select MODULES_USE_ELF_RELA select CLONE_BACKWARDS + select ARCH_USE_BUILTIN_BSWAP config EARLY_PRINTK bool |