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/* $OpenBSD: strcmp.S,v 1.3 2005/08/07 11:30:38 espie Exp $ */
/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*/
#include <machine/asm.h>
/*
* NOTE: I've unrolled the loop eight times: large enough to make a
* significant difference, and small enough not to totally trash the
* cache.
*/
ENTRY(strcmp)
movl 0x04(%esp),%eax
movl 0x08(%esp),%edx
jmp L2 /* Jump into the loop! */
.align 2,0x90
L1: incl %eax
incl %edx
L2: movb (%eax),%cl
testb %cl,%cl /* null terminator??? */
jz L3
cmpb %cl,(%edx) /* chars match??? */
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
jz L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
jz L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
jz L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
jz L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
jz L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
jz L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
jz L3
cmpb %cl,(%edx)
je L1
.align 2, 0x90
L3: movzbl (%eax),%eax /* unsigned comparison */
movzbl (%edx),%edx
subl %edx,%eax
ret
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