/* $NetBSD: memcmp.S,v 1.4 2011/01/25 02:38:15 matt Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* int memcmp(s1, s2, n) */ #include "DEFS.h" #ifdef LIBC_SCCS RCSID("$NetBSD: memcmp.S,v 1.4 2011/01/25 02:38:15 matt Exp $") #endif ENTRY(memcmp, 0) movl 12(%ap),%r0 jeql 9f movq 4(%ap),%r1 ashl $-2,%r0,%r3 # convert len to long words jeql 2f 1: cmpl (%r1)+,(%r2)+ # no "cmpq" alas jneq 7f sobgtr %r3,1b 2: bicl3 $-4,%r0,%r3 # handle at most 3 extra bytes jeql 4f 3: cmpb (%r1)+,(%r2)+ jneq 8f sobgtr %r3,3b 4: clrl %r0 # we had a match ret 7: # backup, and do a byte compare tstl -(%r1) tstl -(%r2) movl $4,%r3 jbr 3b 8: movzbl -(%r1),%r3 movzbl -(%r2),%r4 subl3 %r4,%r3,%r0 9: ret END(memcmp) |