1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * From: sys/powerpc/powerpc/bcopy.c 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD$"); 37 38#include <sys/param.h> 39#include <sys/systm.h> 40 41/* 42 * sizeof(word) MUST BE A POWER OF TWO 43 * SO THAT wmask BELOW IS ALL ONES 44 */ 45typedef long word; /* "word" used for optimal copy speed */ 46 47#define wsize sizeof(word) 48#define wmask (wsize - 1) 49 50/* 51 * Copy a block of memory, handling overlap. 52 * This is the routine that actually implements 53 * (the portable versions of) bcopy, memcpy, and memmove. 54 */ 55void * 56memcpy(void *dst0, const void *src0, size_t length) 57{ 58 char *dst; 59 const char *src; 60 size_t t; 61 62 dst = dst0; 63 src = src0; 64 65 if (length == 0 || dst == src) { /* nothing to do */ 66 goto done; 67 } 68 69 /* 70 * Macros: loop-t-times; and loop-t-times, t>0 71 */ 72#define TLOOP(s) if (t) TLOOP1(s) 73#define TLOOP1(s) do { s; } while (--t) 74 75 if ((unsigned long)dst < (unsigned long)src) { 76 /* 77 * Copy forward. 78 */ 79 t = (size_t)src; /* only need low bits */ 80 81 if ((t | (uintptr_t)dst) & wmask) { 82 /* 83 * Try to align operands. This cannot be done 84 * unless the low bits match. 85 */ 86 if ((t ^ (uintptr_t)dst) & wmask || length < wsize) { 87 t = length; 88 } else { 89 t = wsize - (t & wmask); 90 } 91 92 length -= t; 93 TLOOP1(*dst++ = *src++); 94 } 95 /* 96 * Copy whole words, then mop up any trailing bytes. 97 */ 98 t = length / wsize; 99 TLOOP(*(word *)dst = *(const word *)src; src += wsize; 100 dst += wsize); 101 t = length & wmask; 102 TLOOP(*dst++ = *src++); 103 } else { 104 /* 105 * Copy backwards. Otherwise essentially the same. 106 * Alignment works as before, except that it takes 107 * (t&wmask) bytes to align, not wsize-(t&wmask). 108 */ 109 src += length; 110 dst += length; 111 t = (uintptr_t)src; 112 113 if ((t | (uintptr_t)dst) & wmask) { 114 if ((t ^ (uintptr_t)dst) & wmask || length <= wsize) { 115 t = length; 116 } else { 117 t &= wmask; 118 } 119 120 length -= t; 121 TLOOP1(*--dst = *--src); 122 } 123 t = length / wsize; 124 TLOOP(src -= wsize; dst -= wsize; 125 *(word *)dst = *(const word *)src); 126 t = length & wmask; 127 TLOOP(*--dst = *--src); 128 } 129done: 130 return (dst0); 131} 132 133void 134bcopy(const void *src0, void *dst0, size_t length) 135{ 136 137 memcpy(dst0, src0, length); 138} 139 140