Commit dd1ef4ec authored Mar 12, 2009 by Jan Beulich Committed by Ingo Molnar Mar 12, 2009

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>

parent c2810188

arch/x86/lib/memcpy_64.S

+0 −7

Original line number	Diff line number	Diff line
		@@ -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)