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[/] [openrisc/] [trunk/] [gnu-old/] [newlib-1.17.0/] [newlib/] [libc/] [machine/] [i386/] [strchr.S] - Blame information for rev 855

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Line No. Rev Author Line
1 148 jeremybenn 
/*
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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 (strchr)
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       SOTYPE_FUNCTION(strchr)
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SYM (strchr):
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        pushl ebp
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        movl esp,ebp
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        pushl edi
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        pushl ebx
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        xorl ebx,ebx
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        movl 8(ebp),edi
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        addb 12(ebp),bl
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#ifndef __OPTIMIZE_SIZE__
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/* Special case strchr(p,0).  */
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        je L25
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/* Do byte-wise checks until string is aligned.  */
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        test $3,edi
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        je L5
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        movl edi,eax
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        movb (eax),cl
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        testb cl,cl
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        je L14
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        cmpb bl,cl
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        je L19
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        incl edi
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        test $3,edi
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        je L5
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        movl edi,eax
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        movb (eax),cl
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        testb cl,cl
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        je L14
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        cmpb bl,cl
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        je L19
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        incl edi
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        test $3,edi
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        je L5
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        movl edi,eax
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        movb (eax),cl
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        testb cl,cl
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        je L14
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        cmpb bl,cl
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        je L19
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        incl edi
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/* create 4 byte mask which is just the desired byte repeated 4 times */
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L5:
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        movl ebx,ecx
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        sall $8,ebx
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        subl $4,edi
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        orl ecx,ebx
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        movl ebx,edx
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        sall $16,ebx
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        orl edx,ebx
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/* loop performing 4 byte mask checking for 0 byte or desired byte */
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        .p2align 4,,7
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L10:
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        addl $4,edi
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        movl (edi),ecx
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        leal -16843009(ecx),edx
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        movl ecx,eax
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        notl eax
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        andl eax,edx
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        testl $-2139062144,edx
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        jne L9
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        xorl ebx,ecx
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        leal -16843009(ecx),edx
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        notl ecx
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        andl ecx,edx
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        testl $-2139062144,edx
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        je L10
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#endif /* not __OPTIMIZE_SIZE__ */
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/* loop while (*s && *s++ != c) */
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L9:
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        leal -1(edi),eax
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        .p2align 4,,7
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L15:
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        incl eax
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        movb (eax),dl
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        testb dl,dl
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        je L14
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        cmpb bl,dl
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        jne L15
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L14:
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/*  if (*s == c) return address otherwise return NULL */
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        cmpb bl,(eax)
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        je L19
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        xorl eax,eax
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L19:
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        leal -8(ebp),esp
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        popl ebx
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        popl edi
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        leave
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        ret
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#ifndef __OPTIMIZE_SIZE__
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/* Special case strchr(p,0).  */
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#if 0
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        /* Hideous performance on modern machines.  */
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L25:
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        cld
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        movl $-1,ecx
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        xor eax,eax
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        repnz
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        scasb
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        leal -1(edi),eax
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        jmp L19
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#endif
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L25:
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/* Do byte-wise checks until string is aligned.  */
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        test $3,edi
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        je L26
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        movl edi,eax
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        movb (eax),cl
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        testb cl,cl
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        je L19
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        incl edi
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        test $3,edi
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        je L26
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        movl edi,eax
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        movb (eax),cl
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        testb cl,cl
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        je L19
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        incl edi
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        test $3,edi
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        je L26
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        movl edi,eax
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        movb (eax),cl
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        testb cl,cl
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        je L19
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        incl edi
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L26:
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        subl $4,edi
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/* loop performing 4 byte mask checking for desired 0 byte */
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        .p2align 4,,7
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L27:
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        addl $4,edi
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        movl (edi),ecx
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        leal -16843009(ecx),edx
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        movl ecx,eax
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        notl eax
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        andl eax,edx
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        testl $-2139062144,edx
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        je L27
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        jmp L9
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#endif /* !__OPTIMIZE_SIZE__ */

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