fef
5a5135f416
As of now, everything except the code imported from FreeBSD is proprietary. Of course, it won't be like this for long, only until we have decided which license we like to use. The rationale is that releasing everything under a copyleft license later is always easier than doing so immediately and then changing it afterwards. Naturally, any changes made before this commit are still subject to the terms of the CNPL.
132 lines
3.8 KiB
C
132 lines
3.8 KiB
C
/* See the end of this file for copyright and license terms. */
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#include <gay/types.h>
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#define wsize sizeof(word_t)
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#define wmask (wsize - 1)
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/*
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* Copy a block of memory, handling overlap.
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* This is the routine that actually implements
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* (the portable versions of) bcopy, memcpy, and memmove.
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*/
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#if defined(MEMCOPY) || defined(MEMMOVE)
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#include <string.h>
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void *
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#ifdef MEMCOPY
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memcpy
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#else
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memmove
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#endif
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(void *dst0, const void *src0, size_t length)
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#else
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#include <strings.h>
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void
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bcopy(const void *src0, void *dst0, usize length)
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#endif
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{
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char *dst = dst0;
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const char *src = src0;
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usize t;
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if (length == 0 || dst == src) /* nothing to do */
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goto done;
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/*
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* Macros: loop-t-times; and loop-t-times, t>0
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*/
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#define TLOOP(s) if (t) TLOOP1(s)
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#define TLOOP1(s) do { s; } while (--t)
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if ((unsigned long)dst < (unsigned long)src) {
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/*
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* Copy forward.
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*/
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t = (uintptr_t)src; /* only need low bits */
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if ((t | (uintptr_t)dst) & wmask) {
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/*
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* Try to align operands. This cannot be done
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* unless the low bits match.
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*/
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if ((t ^ (uintptr_t)dst) & wmask || length < wsize)
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t = length;
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else
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t = wsize - (t & wmask);
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length -= t;
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TLOOP1(*dst++ = *src++);
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}
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/*
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* Copy whole words, then mop up any trailing bytes.
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*/
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t = length / wsize;
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TLOOP(*(word_t *)(void *)dst = *(const word_t *)(const void *)src;
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src += wsize; dst += wsize);
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t = length & wmask;
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TLOOP(*dst++ = *src++);
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} else {
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/*
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* Copy backwards. Otherwise essentially the same.
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* Alignment works as before, except that it takes
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* (t&wmask) bytes to align, not wsize-(t&wmask).
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*/
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src += length;
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dst += length;
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t = (uintptr_t)src;
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if ((t | (uintptr_t)dst) & wmask) {
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if ((t ^ (uintptr_t)dst) & wmask || length <= wsize)
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t = length;
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else
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t &= wmask;
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length -= t;
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TLOOP1(*--dst = *--src);
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}
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t = length / wsize;
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TLOOP(src -= wsize; dst -= wsize;
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*(word_t *)(void *)dst = *(const word_t *)(const void *)src);
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t = length & wmask;
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TLOOP(*--dst = *--src);
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}
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done:
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#if defined(MEMCOPY) || defined(MEMMOVE)
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return dst0;
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#else
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return;
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#endif
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}
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/*
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* Copyright (c) 2021 fef <owo@fef.moe>
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Chris Torek.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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