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/*
* ====================================================
* Copyright (C) 1998, 2002, 2008 by Red Hat Inc. All rights reserved.
*
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include "i386mach.h"
.global SYM (memchr)
SOTYPE_FUNCTION(memchr)
SYM (memchr):
pushl ebp
movl esp,ebp
pushl edi
movzbl 12(ebp),eax
movl 16(ebp),ecx
movl 8(ebp),edi
xorl edx,edx
testl ecx,ecx
jz L20
#ifdef __OPTIMIZE_SIZE__
cld
repnz
scasb
setnz dl
decl edi
#else /* !__OPTIMIZE_SIZE__ */
/* Do byte-wise checks until string is aligned. */
testl $3,edi
je L5
cmpb (edi),al
je L15
incl edi
decl ecx
je L20
testl $3,edi
je L5
cmpb (edi),al
je L15
incl edi
decl ecx
je L20
testl $3,edi
je L5
cmpb (edi),al
je L15
incl edi
decl ecx
je L20
/* Create a mask, then check a word at a time. */
L5:
movb al,ah
movl eax,edx
sall $16,edx
orl edx,eax
pushl ebx
.p2align 4,,7
L8:
subl $4,ecx
jc L9
movl (edi),edx
addl $4,edi
xorl eax,edx
leal -16843009(edx),ebx
notl edx
andl edx,ebx
testl $-2139062144,ebx
je L8
subl $4,edi
L9:
popl ebx
xorl edx,edx
addl $4,ecx
je L20
/* Final byte-wise checks. */
.p2align 4,,7
L10:
cmpb (edi),al
je L15
incl edi
decl ecx
jne L10
xorl edi,edi
#endif /* !__OPTIMIZE_SIZE__ */
L15:
decl edx
andl edi,edx
L20:
movl edx,eax
leal -4(ebp),esp
popl edi
leave
ret
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