108 lines
2.4 KiB
C
108 lines
2.4 KiB
C
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/* @(#)movecbytes.c 1.2 16/11/05 Copyright 2016 J. Schilling */
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/*
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* move data, stop if character c is copied
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*
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* Copyright (c) 2016 J. Schilling
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*/
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/*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* See the file CDDL.Schily.txt in this distribution for details.
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* A copy of the CDDL is also available via the Internet at
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* http://www.opensource.org/licenses/cddl1.txt
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file CDDL.Schily.txt from this distribution.
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*/
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#include <schily/standard.h>
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#include <schily/types.h>
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#include <schily/schily.h>
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#define DO8(a) a; a; a; a; a; a; a; a;
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/*
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* movecbytes(from, to, c, cnt) is the same as memccpy(to, from, c, cnt)
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*/
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EXPORT char *
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movecbytes(fromv, tov, c, cnt)
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const void *fromv;
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void *tov;
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register int c;
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size_t cnt;
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{
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register const char *from = fromv;
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register char *to = tov;
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register size_t n;
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if ((n = cnt) == 0)
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return (NULL);
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#define separate_code
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#ifdef separate_code
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while (n >= 8) {
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/* BEGIN CSTYLED */
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DO8(
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if ((*to++ = *from++) == (char)c)
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return (to);
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);
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/* END CSTYLED */
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n -= 8;
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}
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switch (n) {
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case 7: if ((*to++ = *from++) == (char)c)
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return (to);
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case 6: if ((*to++ = *from++) == (char)c)
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return (to);
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case 5: if ((*to++ = *from++) == (char)c)
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return (to);
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case 4: if ((*to++ = *from++) == (char)c)
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return (to);
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case 3: if ((*to++ = *from++) == (char)c)
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return (to);
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case 2: if ((*to++ = *from++) == (char)c)
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return (to);
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case 1: if ((*to++ = *from++) == (char)c)
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return (to);
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}
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#else
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/*
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* This variant should be as fast as the code above but
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* half the size. Unfortunately, most compilers do not optmize
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* it correctly.
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*/
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int rest = n % 8;
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n -= rest;
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switch (rest) {
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case 0: while (n != 0) {
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n -= 8;
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if ((*to++ = *from++) == (char)c)
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return (to);
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case 7: if ((*to++ = *from++) == (char)c)
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return (to);
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case 6: if ((*to++ = *from++) == (char)c)
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return (to);
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case 5: if ((*to++ = *from++) == (char)c)
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return (to);
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case 4: if ((*to++ = *from++) == (char)c)
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return (to);
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case 3: if ((*to++ = *from++) == (char)c)
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return (to);
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case 2: if ((*to++ = *from++) == (char)c)
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return (to);
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case 1: if ((*to++ = *from++) == (char)c)
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return (to);
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}
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}
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#endif
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return (NULL);
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}
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