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