1*f14fb602SLionel Sambuc/* $NetBSD: memcpy.S,v 1.3 2011/01/25 04:45:28 matt Exp $ */ 2b6cbf720SGianluca Guida/*- 3b6cbf720SGianluca Guida * Copyright (c) 1990, 1993 4b6cbf720SGianluca Guida * The Regents of the University of California. All rights reserved. 5b6cbf720SGianluca Guida * 6b6cbf720SGianluca Guida * Redistribution and use in source and binary forms, with or without 7b6cbf720SGianluca Guida * modification, are permitted provided that the following conditions 8b6cbf720SGianluca Guida * are met: 9b6cbf720SGianluca Guida * 1. Redistributions of source code must retain the above copyright 10b6cbf720SGianluca Guida * notice, this list of conditions and the following disclaimer. 11b6cbf720SGianluca Guida * 2. Redistributions in binary form must reproduce the above copyright 12b6cbf720SGianluca Guida * notice, this list of conditions and the following disclaimer in the 13b6cbf720SGianluca Guida * documentation and/or other materials provided with the distribution. 14b6cbf720SGianluca Guida * 3. Neither the name of the University nor the names of its contributors 15b6cbf720SGianluca Guida * may be used to endorse or promote products derived from this software 16b6cbf720SGianluca Guida * without specific prior written permission. 17b6cbf720SGianluca Guida * 18b6cbf720SGianluca Guida * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19b6cbf720SGianluca Guida * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20b6cbf720SGianluca Guida * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21b6cbf720SGianluca Guida * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22b6cbf720SGianluca Guida * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23b6cbf720SGianluca Guida * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24b6cbf720SGianluca Guida * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25b6cbf720SGianluca Guida * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26b6cbf720SGianluca Guida * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27b6cbf720SGianluca Guida * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28b6cbf720SGianluca Guida * SUCH DAMAGE. 29b6cbf720SGianluca Guida */ 30b6cbf720SGianluca Guida 31*f14fb602SLionel Sambuc#include <machine/asm.h> 32*f14fb602SLionel Sambuc 33*f14fb602SLionel Sambuc/* .asciz "@(#)memcpy.s 8.1 (Berkeley) 6/4/93" */ 34*f14fb602SLionel SambucRCSID("$NetBSD: memcpy.S,v 1.3 2011/01/25 04:45:28 matt Exp $") 35b6cbf720SGianluca Guida 36b6cbf720SGianluca Guida/* 37b6cbf720SGianluca Guida * void *memcpy(dst, src, size) 38b6cbf720SGianluca Guida * returns dst 39b6cbf720SGianluca Guida * 40b6cbf720SGianluca Guida * This optimises the usual case (count < 65536) at the expense 41b6cbf720SGianluca Guida * of some extra memory references and branches when count >= 65536. 42b6cbf720SGianluca Guida */ 43b6cbf720SGianluca Guida 44b6cbf720SGianluca GuidaENTRY(memcpy, 0) 45b6cbf720SGianluca Guida movzwl $65535,%r0 /* %r0 = 64K (needed below) */ 46b6cbf720SGianluca Guida movq 8(%ap),%r1 /* %r1 = src, %r2 = length */ 47b6cbf720SGianluca Guida movl 4(%ap),%r3 /* %r3 = dst */ 48b6cbf720SGianluca Guida cmpl %r1,%r3 49b6cbf720SGianluca Guida bgtru 1f /* normal forward case */ 50b6cbf720SGianluca Guida beql 2f /* equal, nothing to do */ 51b6cbf720SGianluca Guida addl2 %r2,%r1 /* overlaps iff src<dst but src+len>dst */ 52b6cbf720SGianluca Guida cmpl %r1,%r3 53b6cbf720SGianluca Guida bgtru 4f /* overlapping, must move backwards */ 54b6cbf720SGianluca Guida subl2 %r2,%r1 55b6cbf720SGianluca Guida 56b6cbf720SGianluca Guida1: /* move forward */ 57b6cbf720SGianluca Guida cmpl %r2,%r0 58b6cbf720SGianluca Guida bgtru 3f /* stupid movc3 limitation */ 59b6cbf720SGianluca Guida movc3 %r2,(%r1),(%r3) /* move it all */ 60b6cbf720SGianluca Guida2: 61b6cbf720SGianluca Guida movl 4(%ap),%r0 /* return original dst */ 62b6cbf720SGianluca Guida ret 63b6cbf720SGianluca Guida3: 64b6cbf720SGianluca Guida subl2 %r0,12(%ap) /* adjust length by 64K */ 65b6cbf720SGianluca Guida movc3 %r0,(%r1),(%r3) /* move 64K */ 66b6cbf720SGianluca Guida movl 12(%ap),%r2 67b6cbf720SGianluca Guida decw %r0 /* from 0 to 65535 */ 68b6cbf720SGianluca Guida brb 1b /* retry */ 69b6cbf720SGianluca Guida 70b6cbf720SGianluca Guida4: /* move backward */ 71b6cbf720SGianluca Guida addl2 %r2,%r3 72b6cbf720SGianluca Guida5: 73b6cbf720SGianluca Guida cmpl %r2,%r0 74b6cbf720SGianluca Guida bgtru 6f /* stupid movc3 limitation */ 75b6cbf720SGianluca Guida subl2 %r2,%r1 76b6cbf720SGianluca Guida subl2 %r2,%r3 77b6cbf720SGianluca Guida movc3 %r2,(%r1),(%r3) /* move it all */ 78b6cbf720SGianluca Guida movl 4(%ap),%r0 /* return original dst */ 79b6cbf720SGianluca Guida ret 80b6cbf720SGianluca Guida6: 81b6cbf720SGianluca Guida subl2 %r0,12(%ap) /* adjust length by 64K */ 82b6cbf720SGianluca Guida subl2 %r0,%r1 83b6cbf720SGianluca Guida subl2 %r0,%r3 84b6cbf720SGianluca Guida movc3 %r0,(%r1),(%r3) /* move 64K */ 85b6cbf720SGianluca Guida movl 12(%ap),%r2 86b6cbf720SGianluca Guida decw %r0 87b6cbf720SGianluca Guida subl2 %r0,%r1 88b6cbf720SGianluca Guida subl2 %r0,%r3 89b6cbf720SGianluca Guida brb 5b 90*f14fb602SLionel SambucEND(memcpy) 91