1/* 2 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6/* 7 * Copyright 2019 Joyent, Inc. 8 */ 9 10/*- 11 * Copyright (c) 1993 The Regents of the University of California. 12 * All rights reserved. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * $FreeBSD: src/sys/amd64/amd64/support.S,v 1.102 2003/10/02 05:08:13 alc Exp $ 43 */ 44 45#include <sys/asm_linkage.h> 46 47/* 48 * Adapted from fbsd bcopy(). 49 * 50 * bcopy(src, dst, cnt) 51 * rdi, rsi, rdx 52 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 53 */ 54 55 ENTRY(ovbcopy) 56 xchgq %rsi,%rdi 57 movq %rdx,%rcx 58 59 movq %rdi,%rax 60 subq %rsi,%rax 61 cmpq %rcx,%rax /* overlapping && src < dst? */ 62 jb reverse 63 64 shrq $3,%rcx /* copy by 64-bit words */ 65 cld /* nope, copy forwards */ 66 rep 67 movsq 68 movq %rdx,%rcx 69 andq $7,%rcx /* any bytes left? */ 70 rep 71 movsb 72 ret 73 74reverse: 75 addq %rcx,%rdi /* copy backwards */ 76 addq %rcx,%rsi 77 decq %rdi 78 decq %rsi 79 andq $7,%rcx /* any fractional bytes? */ 80 std 81 rep 82 movsb 83 movq %rdx,%rcx /* copy remainder by 32-bit words */ 84 shrq $3,%rcx 85 subq $7,%rsi 86 subq $7,%rdi 87 rep 88 movsq 89 cld 90 ret 91 SET_SIZE(ovbcopy) 92 93