1*b6cbf720SGianluca Guida/* $NetBSD: memcmp.S,v 1.1 2005/12/20 19:28:49 christos Exp $ */ 2*b6cbf720SGianluca Guida 3*b6cbf720SGianluca Guida/*- 4*b6cbf720SGianluca Guida * Copyright (c) 1990 The Regents of the University of California. 5*b6cbf720SGianluca Guida * All rights reserved. 6*b6cbf720SGianluca Guida * 7*b6cbf720SGianluca Guida * This code is derived from software contributed to Berkeley by 8*b6cbf720SGianluca Guida * the Systems Programming Group of the University of Utah Computer 9*b6cbf720SGianluca Guida * Science Department. 10*b6cbf720SGianluca Guida * 11*b6cbf720SGianluca Guida * Redistribution and use in source and binary forms, with or without 12*b6cbf720SGianluca Guida * modification, are permitted provided that the following conditions 13*b6cbf720SGianluca Guida * are met: 14*b6cbf720SGianluca Guida * 1. Redistributions of source code must retain the above copyright 15*b6cbf720SGianluca Guida * notice, this list of conditions and the following disclaimer. 16*b6cbf720SGianluca Guida * 2. Redistributions in binary form must reproduce the above copyright 17*b6cbf720SGianluca Guida * notice, this list of conditions and the following disclaimer in the 18*b6cbf720SGianluca Guida * documentation and/or other materials provided with the distribution. 19*b6cbf720SGianluca Guida * 3. Neither the name of the University nor the names of its contributors 20*b6cbf720SGianluca Guida * may be used to endorse or promote products derived from this software 21*b6cbf720SGianluca Guida * without specific prior written permission. 22*b6cbf720SGianluca Guida * 23*b6cbf720SGianluca Guida * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24*b6cbf720SGianluca Guida * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25*b6cbf720SGianluca Guida * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26*b6cbf720SGianluca Guida * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27*b6cbf720SGianluca Guida * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28*b6cbf720SGianluca Guida * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29*b6cbf720SGianluca Guida * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30*b6cbf720SGianluca Guida * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31*b6cbf720SGianluca Guida * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32*b6cbf720SGianluca Guida * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33*b6cbf720SGianluca Guida * SUCH DAMAGE. 34*b6cbf720SGianluca Guida */ 35*b6cbf720SGianluca Guida 36*b6cbf720SGianluca Guida#include <machine/asm.h> 37*b6cbf720SGianluca Guida 38*b6cbf720SGianluca Guida#if defined(LIBC_SCCS) && !defined(lint) 39*b6cbf720SGianluca Guida#if 0 40*b6cbf720SGianluca Guida RCSID("from: @(#)bcmp.s 5.1 (Berkeley) 5/12/90") 41*b6cbf720SGianluca Guida#else 42*b6cbf720SGianluca Guida RCSID("$NetBSD: memcmp.S,v 1.1 2005/12/20 19:28:49 christos Exp $") 43*b6cbf720SGianluca Guida#endif 44*b6cbf720SGianluca Guida#endif /* LIBC_SCCS and not lint */ 45*b6cbf720SGianluca Guida 46*b6cbf720SGianluca Guida/* memcmp(s1, s2, n) */ 47*b6cbf720SGianluca Guida 48*b6cbf720SGianluca Guida/* 49*b6cbf720SGianluca Guida * This is probably not the best we can do, but it is still 2-10 times 50*b6cbf720SGianluca Guida * faster than the C version in the portable gen directory. 51*b6cbf720SGianluca Guida * 52*b6cbf720SGianluca Guida * Things that might help: 53*b6cbf720SGianluca Guida * - longword align when possible (only on the 68020) 54*b6cbf720SGianluca Guida * - use nested DBcc instructions or use one and limit size to 64K 55*b6cbf720SGianluca Guida */ 56*b6cbf720SGianluca GuidaENTRY(memcmp) 57*b6cbf720SGianluca Guida movl %sp@(4),%a0 | string 1 58*b6cbf720SGianluca Guida movl %sp@(8),%a1 | string 2 59*b6cbf720SGianluca Guida movl %sp@(12),%d0 | length 60*b6cbf720SGianluca Guida jeq bcdone | if zero, nothing to do 61*b6cbf720SGianluca Guida movl %a0,%d1 62*b6cbf720SGianluca Guida btst #0,%d1 | string 1 address odd? 63*b6cbf720SGianluca Guida jeq bceven | no, skip alignment 64*b6cbf720SGianluca Guida cmpmb %a0@+,%a1@+ | yes, compare a byte 65*b6cbf720SGianluca Guida jne bcnoteq | not equal, return non-zero 66*b6cbf720SGianluca Guida subql #1,%d0 | adjust count 67*b6cbf720SGianluca Guida jeq bcdone | count 0, reutrn zero 68*b6cbf720SGianluca Guidabceven: 69*b6cbf720SGianluca Guida movl %a1,%d1 70*b6cbf720SGianluca Guida btst #0,%d1 | string 2 address odd? 71*b6cbf720SGianluca Guida jne bcbloop | yes, no hope for alignment, compare bytes 72*b6cbf720SGianluca Guida movl %d0,%d1 | no, both even 73*b6cbf720SGianluca Guida lsrl #2,%d1 | convert count to longword count 74*b6cbf720SGianluca Guida jeq bcbloop | count 0, skip longword loop 75*b6cbf720SGianluca Guidabclloop: 76*b6cbf720SGianluca Guida cmpml %a0@+,%a1@+ | compare a longword 77*b6cbf720SGianluca Guida jne bcnoteql | not equal, return non-zero 78*b6cbf720SGianluca Guida subql #1,%d1 | adjust count 79*b6cbf720SGianluca Guida jne bclloop | still more, keep comparing 80*b6cbf720SGianluca Guida andl #3,%d0 | what remains 81*b6cbf720SGianluca Guida jeq bcdone | nothing, all done 82*b6cbf720SGianluca Guidabcbloop: 83*b6cbf720SGianluca Guida cmpmb %a0@+,%a1@+ | compare a byte 84*b6cbf720SGianluca Guida jne bcnoteq | not equal, return non-zero 85*b6cbf720SGianluca Guida subql #1,%d0 | adjust count 86*b6cbf720SGianluca Guida jne bcbloop | still more, keep going 87*b6cbf720SGianluca Guida rts 88*b6cbf720SGianluca Guidabcnoteql: 89*b6cbf720SGianluca Guida subql #4,%a0 90*b6cbf720SGianluca Guida subql #4,%a1 91*b6cbf720SGianluca Guida movl #4,%d0 92*b6cbf720SGianluca Guida jra bcbloop 93*b6cbf720SGianluca Guidabcnoteq: 94*b6cbf720SGianluca Guida clrl %d0 95*b6cbf720SGianluca Guida clrl %d1 96*b6cbf720SGianluca Guida movb %a0@-,%d0 97*b6cbf720SGianluca Guida movb %a1@-,%d1 98*b6cbf720SGianluca Guida subl %d1,%d0 99*b6cbf720SGianluca Guidabcdone: 100*b6cbf720SGianluca Guida rts 101