[PATCH 4/8] lib/lzo: 64-bit CTZ on arm64

[Dave Rodgman]

From: Matt Sealey <matt.sealey@xxxxxxx>

LZO leaves some performance on the table by not realising that arm64 can
optimize count-trailing-zeros bit operations.

Add CONFIG_ARM64 to the checked definitions alongside CONFIG_X86_64 to
enable the use of rbit/clz instructions on full 64-bit quantities.

Link: http://lkml.kernel.org/r/20181127161913.23863-5-dave.rodgman@xxxxxxx
Signed-off-by: Matt Sealey <matt.sealey@xxxxxxx>
Signed-off-by: Dave Rodgman <dave.rodgman@xxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Markus F.X.J. Oberhumer <markus@xxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Nitin Gupta <nitingupta910@xxxxxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx>
Cc: Sonny Rao <sonnyrao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
---
 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 c0193f726db0..c8965dc181df 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(CONFIG_X86_64)
+#elif defined(CONFIG_X86_64) || defined(CONFIG_ARM64)
 #define LZO_USE_CTZ64	1
 #define LZO_USE_CTZ32	1
 #elif defined(CONFIG_X86) || defined(CONFIG_PPC)
-- 
2.17.1