mirror of https://gitlab.com/rnger/amath
118 lines
3.7 KiB
C
118 lines
3.7 KiB
C
/*-
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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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* Mike Hibler and 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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* 4. 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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/**
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* @file memset.c
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* @brief Fill block of memory with a constant value.
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*
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* Code originate from FreeBSD base, revision 229286.
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*
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* Browse at:
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* https://svnweb.freebsd.org/base/head/lib/libc/string/memset.c?revision=229286
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*
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*/
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#include "clib.h"
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#if __GNUC__ > 2
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#pragma GCC diagnostic ignored "-Wcast-align"
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#endif
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#ifdef _WIN32
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typedef unsigned long long mem_ptr;
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#else
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typedef unsigned long mem_ptr;
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#endif
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/**
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* @brief Fill block of memory with a constant value.
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*/
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void MemSet(void *dst0, int c0, unsigned int length)
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{
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unsigned char *dst = (unsigned char*) dst0;
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unsigned int t;
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unsigned int c;
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/*
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* If not enough words, just fill bytes. A length >= 2 words
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* guarantees that at least one of them is `complete' after
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* any necessary alignment. For instance:
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*
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* |-----------|-----------|-----------|
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* |00|01|02|03|04|05|06|07|08|09|0A|00|
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* ^---------------------^
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* dst dst+length-1
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*
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* but we use a minimum of 3 here since the overhead of the code
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* to do word writes is substantial.
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*/
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if (length < 3 * wsize) {
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while (length != 0) {
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*dst++ = c0;
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--length;
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}
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}
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if ((c = (unsigned char)c0) != 0) { /* Fill the word. */
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c = (c << 8) | c; /* u_int is 16 bits. */
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#if UINT_MAX > 0xffff
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c = (c << 16) | c; /* u_int is 32 bits. */
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#endif
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#if UINT_MAX > 0xffffffff
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c = (c << 32) | c; /* u_int is 64 bits. */
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#endif
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}
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/* Align destination by filling in bytes. */
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if ((t = (mem_ptr)dst & wmask) != 0) {
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t = wsize - t;
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length -= t;
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do {
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*dst++ = c0;
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} while (--t != 0);
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}
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/* Fill words. Length was >= 2*words so we know t >= 1 here. */
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t = length / wsize;
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do {
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*(unsigned int*)dst = c;
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dst += wsize;
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} while (--t != 0);
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/* Mop up trailing bytes, if any. */
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t = length & wmask;
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if (t != 0)
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do {
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*dst++ = c0;
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} while (--t != 0);
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}
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