76 lines
2.5 KiB
ArmAsm
76 lines
2.5 KiB
ArmAsm
/*
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* Copyright (c) 1993 Winning Strategies, Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Winning Strategies, Inc.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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__FBSDID("$FreeBSD$");
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/*
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* memcmp (void *b1, void *b2, size_t len)
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*
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* Written by:
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* J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
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*/
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ENTRY(memcmp)
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pushl %edi
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pushl %esi
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movl 12(%esp),%edi
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movl 16(%esp),%esi
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cld /* set compare direction forward */
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movl 20(%esp),%ecx /* compare by words */
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shrl $2,%ecx
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repe
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cmpsl
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jne L5 /* do we match so far? */
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movl 20(%esp),%ecx /* compare remainder by bytes */
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andl $3,%ecx
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repe
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cmpsb
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jne L6 /* do we match? */
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xorl %eax,%eax /* we match, return zero */
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popl %esi
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popl %edi
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ret
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L5: movl $4,%ecx /* We know that one of the next */
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subl %ecx,%edi /* four pairs of bytes do not */
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subl %ecx,%esi /* match. */
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repe
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cmpsb
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L6: movzbl -1(%edi),%eax /* Perform unsigned comparison */
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movzbl -1(%esi),%edx
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subl %edx,%eax
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popl %esi
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popl %edi
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ret
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