[PATCH 3/6] lib/lzo: 64-bit CTZ on Arm aarch64

From: Dave Rodgman
Date: Wed Nov 21 2018 - 06:59:59 EST


From: Matt Sealey <matt.sealey@xxxxxxx>

LZO leaves some performance on the table by not realising that AArch64 can
optimize count-trailing-zeros bit operations.

Add __aarch64__ to the checked definitions alongside __x86_64__ to enable
the use of rbit/clz instructions on full 64-bit quantities.

Signed-off-by: Matt Sealey <matt.sealey@xxxxxxx>
Signed-off-by: Dave Rodgman <dave.rodgman@xxxxxxx>
---
lib/lzo/lzodefs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/lzo/lzodefs.h b/lib/lzo/lzodefs.h
index a9927bbce21f..d167f8fc6795 100644
--- a/lib/lzo/lzodefs.h
+++ b/lib/lzo/lzodefs.h
@@ -28,7 +28,7 @@

#if defined(__BIG_ENDIAN) && defined(__LITTLE_ENDIAN)
#error "conflicting endian definitions"
-#elif defined(__x86_64__)
+#elif defined(__x86_64__) || defined(__aarch64__)
#define LZO_USE_CTZ64 1
#define LZO_USE_CTZ32 1
#elif defined(__i386__) || defined(__powerpc__)
--
2.16.4