From: Dave Rodgman <dave.rodgman@arm.com>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: nd <nd@arm.com>,
"herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
"davem@davemloft.net" <davem@davemloft.net>,
Matt Sealey <Matt.Sealey@arm.com>,
"nitingupta910@gmail.com" <nitingupta910@gmail.com>,
"rpurdie@openedhand.com" <rpurdie@openedhand.com>,
"markus@oberhumer.com" <markus@oberhumer.com>,
"minchan@kernel.org" <minchan@kernel.org>,
"sergey.senozhatsky.work@gmail.com"
<sergey.senozhatsky.work@gmail.com>
Subject: [PATCH 3/6] lib/lzo: 64-bit CTZ on Arm aarch64
Date: Wed, 21 Nov 2018 11:59:33 +0000 [thread overview]
Message-ID: <20181121115922.22864-4-dave.rodgman@arm.com> (raw)
In-Reply-To: <20181121115922.22864-2-dave.rodgman@arm.com>
From: Matt Sealey <matt.sealey@arm.com>
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@arm.com>
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
---
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
next prev parent reply other threads:[~2018-11-21 11:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-21 11:59 [PATCH 1/6] lib/lzo: clean-up by introducing COPY16 Dave Rodgman
2018-11-21 11:59 ` [PATCH 2/6] lib/lzo: enable 64-bit CTZ on Arm Dave Rodgman
2018-11-21 17:31 ` Christoph Hellwig
2018-11-21 18:30 ` Matt Sealey
2018-11-22 3:06 ` Markus F.X.J. Oberhumer
2018-11-21 11:59 ` Dave Rodgman [this message]
2018-11-21 11:59 ` [PATCH 4/6] lib/lzo: fast 8-byte copy on arm64 Dave Rodgman
2018-11-21 11:59 ` [PATCH 5/6] lib/lzo: implement run-length encoding Dave Rodgman
2018-11-21 11:59 ` [PATCH 6/6] lib/lzo: separate lzo-rle from lzo Dave Rodgman
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