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From: Uros Bizjak <ubizjak@gmail.com>
To: linux-crypto@vger.kernel.org, x86@kernel.org
Cc: Uros Bizjak <ubizjak@gmail.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH] crypto: x86/poly1305-intel: Use TEST %reg,%reg instead of CMP $0,%reg
Date: Fri, 27 Nov 2020 11:18:12 +0100	[thread overview]
Message-ID: <20201127101812.72787-1-ubizjak@gmail.com> (raw)

CMP $0,%reg can't set overflow flag, so we can use shorter TEST %reg,%reg
instruction when only zero and sign flags are checked (E,L,LE,G,GE conditions).

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
 arch/x86/crypto/poly1305-x86_64-cryptogams.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/crypto/poly1305-x86_64-cryptogams.pl b/arch/x86/crypto/poly1305-x86_64-cryptogams.pl
index 7d568012cc15..71fae5a09e56 100644
--- a/arch/x86/crypto/poly1305-x86_64-cryptogams.pl
+++ b/arch/x86/crypto/poly1305-x86_64-cryptogams.pl
@@ -251,7 +251,7 @@ $code.=<<___;
 	mov	%rax,8($ctx)
 	mov	%rax,16($ctx)
 
-	cmp	\$0,$inp
+	test	$inp,$inp
 	je	.Lno_key
 ___
 $code.=<<___ if (!$kernel);
-- 
2.26.2


             reply	other threads:[~2020-11-27 10:18 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-27 10:18 Uros Bizjak [this message]
2020-12-04  7:15 ` [PATCH] crypto: x86/poly1305-intel: Use TEST %reg,%reg instead of CMP $0,%reg Herbert Xu

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