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.woodho...@intel.com>
Acked-by: H. Peter Anvin <h...@linux.intel.com>
---
arch/powerpc/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 951a517..064e418 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -146,6 +146,7 @@ config PPC
select MODULES_USE_ELF_RELA
select GENERIC_KERNEL_EXECVE
select CLONE_BACKWARDS
+ select ARCH_USE_BUILTIN_BSWAP
config EARLY_PRINTK
bool
--
1.8.0.1
--
dwmw2
smime.p7s
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