From: "Jan Beulich" <jbeulich@novell.com>
To: <mingo@elte.hu>, <tglx@linutronix.de>, <hpa@zytor.com>
Cc: <linux-kernel@vger.kernel.org>
Subject: [PATCH] x86-64: remove unnecessary spill/reload of rbx from memcpy
Date: Thu, 12 Mar 2009 10:47:13 +0000 [thread overview]
Message-ID: <49B8F641.76E4.0078.0@novell.com> (raw)
This should slightly improve its performance.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
---
arch/x86/lib/memcpy_64.S | 7 -------
1 file changed, 7 deletions(-)
--- linux-2.6.29-rc7/arch/x86/lib/memcpy_64.S 2008-01-24 23:58:37.000000000 +0100
+++ 2.6.29-rc7-x86_64-memcpy-rbx/arch/x86/lib/memcpy_64.S 2008-12-18 10:58:11.000000000 +0100
@@ -33,9 +33,6 @@ ENDPROC(memcpy_c)
ENTRY(__memcpy)
ENTRY(memcpy)
CFI_STARTPROC
- pushq %rbx
- CFI_ADJUST_CFA_OFFSET 8
- CFI_REL_OFFSET rbx, 0
movq %rdi,%rax
movl %edx,%ecx
@@ -102,11 +99,7 @@ ENTRY(memcpy)
jnz .Lloop_1
.Lende:
- popq %rbx
- CFI_ADJUST_CFA_OFFSET -8
- CFI_RESTORE rbx
ret
-.Lfinal:
CFI_ENDPROC
ENDPROC(memcpy)
ENDPROC(__memcpy)
next reply other threads:[~2009-03-12 10:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-12 10:47 Jan Beulich [this message]
2009-03-12 11:57 ` [tip:x86/asm] x86-64: remove unnecessary spill/reload of rbx from memcpy Jan Beulich
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