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/* @(#)cmpbytes.c 1.13 00/05/07 Copyright 1988 J. Schilling */
#ifndef lint
static char sccsid[] =
"@(#)cmpbytes.c 1.13 00/05/07 Copyright 1988 J. Schilling";
#endif /* lint */
/*
* compare data
*
* Copyright (c) 1988 J. Schilling
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <standard.h>
#include <align.h>
#include <schily.h>
#define DO8(a) a;a;a;a;a;a;a;a;
int cmpbytes(fromp, top, cnt)
const void *fromp;
const void *top;
int cnt;
{
register const char *from = (char *)fromp;
register const char *to = (char *)top;
register int n;
/*
* If we change cnt to be unsigned, check for == instead of <=
*/
if ((n = cnt) <= 0)
return (cnt);
if (n >= (int)(8 * sizeof(long))) {
if (l2aligned(from, to)) {
register const long *froml = (const long *)from;
register const long *tol = (const long *)to;
register int rem = n % (8 * sizeof (long));
n /= (8 * sizeof (long));
do {
DO8 (
if (*tol++ != *froml++)
break;
);
} while (--n > 0);
if (n > 0) {
--froml;
--tol;
to = (const char *)tol;
from = (const char *)froml;
goto ldiff;
}
to = (const char *)tol;
from = (const char *)froml;
n = rem;
}
if (n >= 8) {
n -= 8;
do {
DO8 (
if (*to++ != *from++)
goto cdiff;
);
} while ((n -= 8) >= 0);
n += 8;
}
if (n > 0) do {
if (*to++ != *from++)
goto cdiff;
} while (--n > 0);
return (cnt);
}
if (n > 0) do {
if (*to++ != *from++)
goto cdiff;
} while (--n > 0);
return (cnt);
ldiff:
n = sizeof(long);
do {
if (*to++ != *from++)
goto cdiff;
} while (--n > 0);
cdiff:
return (--from - (char *)fromp);
}
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