From fe3955cb297290b0d5dedf5d2694a7cef455010e Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Wed, 19 Dec 2012 15:14:17 +0000 Subject: [PATCH] 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 Acked-by: H. Peter Anvin Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/Kconfig | 1 + 1 file changed, 1 insertion(+) 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