1/* $NetBSD: memcmp.S,v 1.2 2002/02/24 01:06:20 matt Exp $ */ 2/*- 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the University of 17 * California, Berkeley and its contributors. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35/* int memcmp(s1, s2, n) */ 36 37#include "DEFS.h" 38 39ENTRY(memcmp, 0) 40 movl 12(%ap),%r0 41 jeql 9f 42 movq 4(%ap),%r1 43 ashl $-2,%r0,%r3 # convert len to long words 44 jeql 2f 451: 46 cmpl (%r1)+,(%r2)+ # no "cmpq" alas 47 jneq 7f 48 sobgtr %r3,1b 492: 50 bicl3 $-4,%r0,%r3 # handle at most 3 extra bytes 51 jeql 4f 523: 53 cmpb (%r1)+,(%r2)+ 54 jneq 8f 55 sobgtr %r3,3b 564: 57 clrl %r0 # we had a match 58 ret 597: # backup, and do a byte compare 60 tstl -(%r1) 61 tstl -(%r2) 62 movl $4,%r3 63 jbr 3b 648: 65 movzbl -(%r1),%r3 66 movzbl -(%r2),%r4 67 subl3 %r4,%r3,%r0 689: 69 ret 70