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- /*-
- * SPDX-License-Identifier: BSD-3-Clause
- * Copyright (c) 1990 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. 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)
- #if 0
- static char *sccsid = "from: @(#)bcopy.c 5.11 (Berkeley) 6/21/91";
- #endif
- #if 0
- static char *rcsid = "$NetBSD: bcopy.c,v 1.2 1997/04/16 22:09:41 thorpej Exp $";
- #endif
- #endif /* LIBC_SCCS and not lint */
- #include <sys/cdefs.h>
- __FBSDID("$FreeBSD$");
- #include <sys/param.h>
- #ifdef _KERNEL
- #include <sys/systm.h>
- #else
- #include <string.h>
- #endif
- #undef memcpy
- #undef memmove
- #undef bcopy
- /*
- * sizeof(word) MUST BE A POWER OF TWO
- * SO THAT wmask BELOW IS ALL ONES
- */
- typedef long 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.
- */
- void *
- memcpy(void *dst0, const void *src0, size_t length)
- {
- char *dst;
- const char *src;
- size_t t;
- dst = dst0;
- src = src0;
- 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) {
- /*
- * Copy forward.
- */
- t = (size_t)src; /* only need low bits */
- if ((t | (uintptr_t)dst) & wmask) {
- /*
- * Try to align operands. This cannot be done
- * unless the low bits match.
- */
- if ((t ^ (uintptr_t)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 = *(const 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 = (uintptr_t)src;
- if ((t | (uintptr_t)dst) & wmask) {
- if ((t ^ (uintptr_t)dst) & wmask || length <= wsize) {
- t = length;
- } else {
- t &= wmask;
- }
- length -= t;
- TLOOP1(*--dst = *--src);
- }
- t = length / wsize;
- TLOOP(src -= wsize; dst -= wsize;
- *(word *)dst = *(const word *)src);
- t = length & wmask;
- TLOOP(*--dst = *--src);
- }
- done:
- return (dst0);
- }
- __strong_reference(memcpy, memmove);
- void
- (bcopy)(const void *src0, void *dst0, size_t length)
- {
- memcpy(dst0, src0, length);
- }
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