/* * Copyright (c) 1999 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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. */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)bcopy.c 8.1 (Berkeley) 6/4/93"; #endif /* LIBC_SCCS and not lint */ #include <sys/cdefs.h> #include <string.h> /* * sizeof(word) MUST BE A POWER OF TWO * SO THAT wmask BELOW IS ALL ONES */ typedef int word; /* "word" used for optimal copy speed */ #define wsize sizeof(word) #define wmask (wsize - 1) /* * Copy a block of memory, handling overlap. * This is the routine that actually implements * (the portable versions of) bcopy, memcpy, and memmove. */ #ifdef MEMCOPY void * memcpy(dst0, src0, length) #else #ifdef MEMMOVE void * memmove(dst0, src0, length) #else void bcopy(src0, dst0, length) #endif #endif void *dst0; const void *src0; register size_t length; { register char *dst = dst0; register const char *src = src0; register size_t t; if (length == 0 || dst == src) /* nothing to do */ goto done; /* * Macros: loop-t-times; and loop-t-times, t>0 */ #define TLOOP(s) if (t) TLOOP1(s) #define TLOOP1(s) do { s; } while (--t) if (((unsigned long)dst < (unsigned long)src) || ((unsigned long)dst >= ((unsigned long)src + length))) { /* * Copy forward. */ t = (int)src; /* only need low bits */ if ((t | (int)dst) & wmask) { /* * Try to align operands. This cannot be done * unless the low bits match. */ if ((t ^ (int)dst) & wmask || length < wsize) t = length; else t = wsize - (t & wmask); length -= t; TLOOP1(*dst++ = *src++); } /* * Copy whole words, then mop up any trailing bytes. */ t = length / wsize; TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize); t = length & wmask; TLOOP(*dst++ = *src++); } else { /* * Copy backwards. Otherwise essentially the same. * Alignment works as before, except that it takes * (t&wmask) bytes to align, not wsize-(t&wmask). */ src += length; dst += length; t = (int)src; if ((t | (int)dst) & wmask) { if ((t ^ (int)dst) & wmask || length <= wsize) t = length; else t &= wmask; length -= t; TLOOP1(*--dst = *--src); } t = length / wsize; TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src); t = length & wmask; TLOOP(*--dst = *--src); } done: #if defined(MEMCOPY) || defined(MEMMOVE) return (dst0); #else return; #endif }