* [PATCH] x86-64: remove unnecessary spill/reload of rbx from memcpy
@ 2009-03-12 10:47 Jan Beulich
2009-03-12 11:57 ` [tip:x86/asm] " Jan Beulich
0 siblings, 1 reply; 2+ messages in thread
From: Jan Beulich @ 2009-03-12 10:47 UTC (permalink / raw)
To: mingo, tglx, hpa; +Cc: linux-kernel
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)
^ permalink raw reply [flat|nested] 2+ messages in thread
* [tip:x86/asm] x86-64: remove unnecessary spill/reload of rbx from memcpy
2009-03-12 10:47 [PATCH] x86-64: remove unnecessary spill/reload of rbx from memcpy Jan Beulich
@ 2009-03-12 11:57 ` Jan Beulich
0 siblings, 0 replies; 2+ messages in thread
From: Jan Beulich @ 2009-03-12 11:57 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, jbeulich, tglx, mingo
Commit-ID: dd1ef4ec4721ddc0a1f2b73a4f67930cb320665c
Gitweb: http://git.kernel.org/tip/dd1ef4ec4721ddc0a1f2b73a4f67930cb320665c
Author: "Jan Beulich" <jbeulich@novell.com>
AuthorDate: Thu, 12 Mar 2009 10:47:13 +0000
Commit: Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 12 Mar 2009 12:04:47 +0100
x86-64: remove unnecessary spill/reload of rbx from memcpy
Impact: micro-optimization
This should slightly improve its performance.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B8F641.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/lib/memcpy_64.S | 7 -------
1 files changed, 0 insertions(+), 7 deletions(-)
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index c22981f..10c0676 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -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)
^ permalink raw reply related [flat|nested] 2+ messages in thread
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