/* * align32 - determine if 32 bit accesses must be aligned * * Copyright (C) 1999,2021 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. * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * Under source code control: 1995/11/23 05:18:06 * File existed as early as: 1995 * * chongo /\oo/\ http://www.isthe.com/chongo/ * Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/ */ #include #include #include "longbits.h" #include "have_unistd.h" #if defined(HAVE_UNISTD_H) #include #endif #include "banned.h" /* include after system header <> includes */ 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); }