From: David Woodhouse <david.woodho...@intel.com>
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>
---
arch/powerpc/Kconfig | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a902a5c..b4ea516 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -78,6 +78,9 @@ config ARCH_HAS_ILOG2_U64
bool
default y if 64BIT
+config ARCH_USE_BUILTIN_BSWAP
+ def_bool y
+
config GENERIC_HWEIGHT
bool
default y
--
1.8.0
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