memcmp.S revision 1.4
1 1.4 matt /* $NetBSD: memcmp.S,v 1.4 2011/01/25 02:38:15 matt Exp $ */ 2 1.1 ragge /*- 3 1.1 ragge * Copyright (c) 1990, 1993 4 1.1 ragge * The Regents of the University of California. All rights reserved. 5 1.1 ragge * 6 1.1 ragge * Redistribution and use in source and binary forms, with or without 7 1.1 ragge * modification, are permitted provided that the following conditions 8 1.1 ragge * are met: 9 1.1 ragge * 1. Redistributions of source code must retain the above copyright 10 1.1 ragge * notice, this list of conditions and the following disclaimer. 11 1.1 ragge * 2. Redistributions in binary form must reproduce the above copyright 12 1.1 ragge * notice, this list of conditions and the following disclaimer in the 13 1.1 ragge * documentation and/or other materials provided with the distribution. 14 1.3 agc * 3. Neither the name of the University nor the names of its contributors 15 1.1 ragge * may be used to endorse or promote products derived from this software 16 1.1 ragge * without specific prior written permission. 17 1.1 ragge * 18 1.1 ragge * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 1.1 ragge * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 1.1 ragge * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 1.1 ragge * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 1.1 ragge * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 1.1 ragge * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 1.1 ragge * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 1.1 ragge * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 1.1 ragge * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 1.1 ragge * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 1.1 ragge * SUCH DAMAGE. 29 1.1 ragge */ 30 1.1 ragge 31 1.1 ragge /* int memcmp(s1, s2, n) */ 32 1.1 ragge 33 1.1 ragge #include "DEFS.h" 34 1.1 ragge 35 1.4 matt #ifdef LIBC_SCCS 36 1.4 matt RCSID("$NetBSD: memcmp.S,v 1.4 2011/01/25 02:38:15 matt Exp $") 37 1.4 matt #endif 38 1.4 matt 39 1.1 ragge ENTRY(memcmp, 0) 40 1.2 matt movl 12(%ap),%r0 41 1.1 ragge jeql 9f 42 1.2 matt movq 4(%ap),%r1 43 1.2 matt ashl $-2,%r0,%r3 # convert len to long words 44 1.1 ragge jeql 2f 45 1.1 ragge 1: 46 1.2 matt cmpl (%r1)+,(%r2)+ # no "cmpq" alas 47 1.1 ragge jneq 7f 48 1.2 matt sobgtr %r3,1b 49 1.1 ragge 2: 50 1.2 matt bicl3 $-4,%r0,%r3 # handle at most 3 extra bytes 51 1.1 ragge jeql 4f 52 1.1 ragge 3: 53 1.2 matt cmpb (%r1)+,(%r2)+ 54 1.1 ragge jneq 8f 55 1.2 matt sobgtr %r3,3b 56 1.1 ragge 4: 57 1.2 matt clrl %r0 # we had a match 58 1.1 ragge ret 59 1.1 ragge 7: # backup, and do a byte compare 60 1.2 matt tstl -(%r1) 61 1.2 matt tstl -(%r2) 62 1.2 matt movl $4,%r3 63 1.1 ragge jbr 3b 64 1.1 ragge 8: 65 1.2 matt movzbl -(%r1),%r3 66 1.2 matt movzbl -(%r2),%r4 67 1.2 matt subl3 %r4,%r3,%r0 68 1.1 ragge 9: 69 1.1 ragge ret 70 1.4 matt END(memcmp) 71
Indexes created Sun Sep 21 14:09:52 GMT 2025