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/*
* align32 - determine if 32 bit accesses must be aligned
*
* Copyright (C) 1999 Landon Curt Noll
*
* Calc is open software; you can redistribute it and/or modify it under
* the terms of the version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* Calc 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 Lesser General
* Public License for more details.
*
* A copy of version 2.1 of the GNU Lesser General Public License is
* distributed with calc under the filename COPYING-LGPL. You should have
* received a copy with calc; if not, write to Free Software Foundation, Inc.
* 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*
* @(#) $Revision: 29.2 $
* @(#) $Id: align32.c,v 29.2 2000/06/07 14:02:13 chongo Exp $
* @(#) $Source: /usr/local/src/cmd/calc/RCS/align32.c,v $
*
* Under source code control: 1995/11/23 05:18:06
* File existed as early as: 1995
*
* chongo <was here> /\oo/\ http://www.isthe.com/chongo/
* Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
*/
#include <stdio.h>
#include <signal.h>
#include "longbits.h"
#include "have_unistd.h"
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
static void buserr(void); /* catch alignment errors */
int
main(void)
{
char byte[2*sizeof(USB32)]; /* mis-alignment buffer */
USB32 *p; /* mis-alignment pointer */
int i;
#if defined(MUST_ALIGN32)
/* force alignment */
printf("#define MUST_ALIGN32\t%c* forced to align 32 bit values *%c\n",
'/', '/');
#else
/* setup to catch alignment bus errors */
signal(SIGBUS, buserr);
signal(SIGSEGV, buserr); /* some systems will generate SEGV instead! */
/* mis-align our long fetches */
for (i=0; i < sizeof(USB32); ++i) {
p = (USB32 *)(byte+i);
*p = i;
*p += 1;
}
/* if we got here, then we can mis-align longs */
printf("#undef MUST_ALIGN32\t%c* can mis-align 32 bit values *%c\n",
'/', '/');
#endif
/* exit(0); */
return 0;
}
/*
* buserr - catch an alignment error
*
* given:
* arg to keep ANSI C happy
*/
/*ARGSUSED*/
static void
buserr(int arg)
{
/* alignment is required */
printf("#define MUST_ALIGN32\t%c* must align 32 bit values *%c\n",
'/', '/');
exit(0);
}
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