Subversion Repositories or1k

/*

 * ====================================================

 * Copyright (C) 1998 by Cygnus Solutions. 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 (memcmp)

SYM (memcmp):

        pushl ebp

        movl esp,ebp

        subl $16,esp

        pushl ebx

        pushl edi

        pushl esi

        movl 8(ebp),edi

        movl 12(ebp),esi

        movl 16(ebp),ecx

        cld

/* check if length is zero in which case just return 0 */

        xorl eax,eax

        testl ecx,ecx

        jz L4

#ifndef __OPTIMIZE_SIZE__

/* if aligned on long boundary, compare doublewords at a time first */

        movl edi,eax

        orl esi,eax

        testb $3,al

        jne BYTECMP

        movl ecx,ebx

        shrl $2,ecx             /* calculate number of long words to compare */

        repz

        cmpsl

        jz L5

        subl $4,esi

        subl $4,edi

        movl $4,ecx

        jmp BYTECMP

L5:

        andl $3,ebx             /* calculate number of remaining bytes */

        movl ebx,ecx

#endif /* not __OPTIMIZE_SIZE__ */

BYTECMP: /* compare any unaligned bytes or remainder bytes */

        repz

        cmpsb

/* set output to be < 0 if less than, 0 if equal, or > 0 if greater than */

L3:

        xorl edx,edx

        movb -1(esi),dl

        xorl eax,eax

        movb -1(edi),al

        subl edx,eax

L4:

        leal -28(ebp),esp

        popl esi

        popl edi

        popl ebx

        leave

        ret