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[/] [openrisc/] [trunk/] [gnu-old/] [newlib-1.17.0/] [newlib/] [libc/] [machine/] [i386/] [memchr.S] - Rev 158

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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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