2 * SPDX-License-Identifier: BSD-3-Clause
3 * Copyright (c) 1990 The Regents of the University of California.
7 * This code is derived from software contributed to Berkeley by
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #if defined(LIBC_SCCS) && !defined(lint)
37 static char *sccsid = "from: @(#)bcopy.c 5.11 (Berkeley) 6/21/91";
40 static char *rcsid = "$NetBSD: bcopy.c,v 1.2 1997/04/16 22:09:41 thorpej Exp $";
42 #endif /* LIBC_SCCS and not lint */
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
46 #include <sys/param.h>
48 #include <sys/systm.h>
58 * sizeof(word) MUST BE A POWER OF TWO
59 * SO THAT wmask BELOW IS ALL ONES
61 typedef long word; /* "word" used for optimal copy speed */
63 #define wsize sizeof(word)
64 #define wmask (wsize - 1)
67 * Copy a block of memory, handling overlap.
68 * This is the routine that actually implements
69 * (the portable versions of) bcopy, memcpy, and memmove.
72 memcpy(void *dst0, const void *src0, size_t length)
81 if (length == 0 || dst == src) { /* nothing to do */
86 * Macros: loop-t-times; and loop-t-times, t>0
88 #define TLOOP(s) if (t) TLOOP1(s)
89 #define TLOOP1(s) do { s; } while (--t)
91 if ((unsigned long)dst < (unsigned long)src) {
95 t = (size_t)src; /* only need low bits */
97 if ((t | (uintptr_t)dst) & wmask) {
99 * Try to align operands. This cannot be done
100 * unless the low bits match.
102 if ((t ^ (uintptr_t)dst) & wmask || length < wsize) {
105 t = wsize - (t & wmask);
109 TLOOP1(*dst++ = *src++);
112 * Copy whole words, then mop up any trailing bytes.
115 TLOOP(*(word *)dst = *(const word *)src; src += wsize;
118 TLOOP(*dst++ = *src++);
121 * Copy backwards. Otherwise essentially the same.
122 * Alignment works as before, except that it takes
123 * (t&wmask) bytes to align, not wsize-(t&wmask).
129 if ((t | (uintptr_t)dst) & wmask) {
130 if ((t ^ (uintptr_t)dst) & wmask || length <= wsize) {
137 TLOOP1(*--dst = *--src);
140 TLOOP(src -= wsize; dst -= wsize;
141 *(word *)dst = *(const word *)src);
143 TLOOP(*--dst = *--src);
149 __strong_reference(memcpy, memmove);
152 (bcopy)(const void *src0, void *dst0, size_t length)
155 memcpy(dst0, src0, length);