00001 /* 00002 * Copyright (C) 2004 by egnite Software GmbH. All rights reserved. 00003 * 00004 * Redistribution and use in source and binary forms, with or without 00005 * modification, are permitted provided that the following conditions 00006 * are met: 00007 * 00008 * 1. Redistributions of source code must retain the above copyright 00009 * notice, this list of conditions and the following disclaimer. 00010 * 2. Redistributions in binary form must reproduce the above copyright 00011 * notice, this list of conditions and the following disclaimer in the 00012 * documentation and/or other materials provided with the distribution. 00013 * 3. Neither the name of the copyright holders nor the names of 00014 * contributors may be used to endorse or promote products derived 00015 * from this software without specific prior written permission. 00016 * 00017 * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS 00018 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00019 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 00020 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE 00021 * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 00022 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 00023 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 00024 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 00025 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 00026 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 00027 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00028 * SUCH DAMAGE. 00029 * 00030 * For additional information see http://www.ethernut.de/ 00031 * 00032 *- 00033 * Copyright (c) 1990 The Regents of the University of California. 00034 * All rights reserved. 00035 * 00036 * This code is derived from software contributed to Berkeley by 00037 * Chris Torek. 00038 * 00039 * Redistribution and use in source and binary forms, with or without 00040 * modification, are permitted provided that the following conditions 00041 * are met: 00042 * 1. Redistributions of source code must retain the above copyright 00043 * notice, this list of conditions and the following disclaimer. 00044 * 2. Redistributions in binary form must reproduce the above copyright 00045 * notice, this list of conditions and the following disclaimer in the 00046 * documentation and/or other materials provided with the distribution. 00047 * 3. Neither the name of the University nor the names of its contributors 00048 * may be used to endorse or promote products derived from this software 00049 * without specific prior written permission. 00050 * 00051 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 00052 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00053 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00054 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 00055 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00056 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 00057 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 00058 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00059 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 00060 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00061 * SUCH DAMAGE. 00062 */ 00063 00064 00065 /* 00066 * $Log$ 00067 * Revision 1.3 2008/02/15 17:13:01 haraldkipp 00068 * Use configurable constant attribute. 00069 * 00070 * Revision 1.2 2005/08/02 17:46:47 haraldkipp 00071 * Major API documentation update. 00072 * 00073 * Revision 1.1 2004/09/08 10:23:43 haraldkipp 00074 * Generic C string library added 00075 * 00076 */ 00077 00078 #include <compiler.h> 00079 #include <string.h> 00080 00085 00100 /* 00101 * sizeof(word) MUST BE A POWER OF TWO 00102 * SO THAT wmask BELOW IS ALL ONES 00103 */ 00104 typedef long word; /* "word" used for optimal copy speed */ 00105 00106 #define wsize sizeof(word) 00107 #define wmask (wsize - 1) 00108 00109 /* 00110 * Copy a block of memory, handling overlap. 00111 * This is the routine that actually implements 00112 * (the portable versions of) bcopy, memcpy, and memmove. 00113 */ 00114 void *memcpy(void *dst0, CONST void *src0, size_t length) 00115 { 00116 register char *dst = dst0; 00117 register CONST char *src = src0; 00118 register size_t t; 00119 00120 if (length == 0 || dst == src) /* nothing to do */ 00121 goto done; 00122 00123 /* 00124 * Macros: loop-t-times; and loop-t-times, t>0 00125 */ 00126 #define TLOOP(s) if (t) TLOOP1(s) 00127 #define TLOOP1(s) do { s; } while (--t) 00128 00129 if ((unsigned long)dst < (unsigned long)src) { 00130 /* 00131 * Copy forward. 00132 */ 00133 t = (long)src; /* only need low bits */ 00134 if ((t | (long)dst) & wmask) { 00135 /* 00136 * Try to align operands. This cannot be done 00137 * unless the low bits match. 00138 */ 00139 if ((t ^ (long)dst) & wmask || length < wsize) 00140 t = length; 00141 else 00142 t = wsize - (t & wmask); 00143 length -= t; 00144 TLOOP1(*dst++ = *src++); 00145 } 00146 /* 00147 * Copy whole words, then mop up any trailing bytes. 00148 */ 00149 t = length / wsize; 00150 TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize); 00151 t = length & wmask; 00152 TLOOP(*dst++ = *src++); 00153 } else { 00154 /* 00155 * Copy backwards. Otherwise essentially the same. 00156 * Alignment works as before, except that it takes 00157 * (t&wmask) bytes to align, not wsize-(t&wmask). 00158 */ 00159 src += length; 00160 dst += length; 00161 t = (long)src; 00162 if ((t | (long)dst) & wmask) { 00163 if ((t ^ (long)dst) & wmask || length <= wsize) 00164 t = length; 00165 else 00166 t &= wmask; 00167 length -= t; 00168 TLOOP1(*--dst = *--src); 00169 } 00170 t = length / wsize; 00171 TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src); 00172 t = length & wmask; 00173 TLOOP(*--dst = *--src); 00174 } 00175 done: 00176 return dst0; 00177 } 00178