align_test.c

创建一个符合iso-9660标准的iso文件系统

/* @(#)align_test.c	1.12 00/01/07 Copyright 1995 J. Schilling */
#ifndef	lint
static	char sccsid[] =
	"@(#)align_test.c	1.12 00/01/07 Copyright 1995 J. Schilling";
#endif
/*
 *	Generate machine dependant align.h
 *
 *	Copyright (c) 1995 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 <mconfig.h>
#include <stdio.h>
#include <standard.h>

/*#define	FORCE_ALIGN*/
/*#define	OFF_ALIGN*/
/*#define	CHECK_ALIGN*/

EXPORT	int	main	__PR((int ac, char** av));

#if	!defined(FORCE_ALIGN) && !defined(OFF_ALIGN) &&	!defined(CHECK_ALIGN)
#define	OFF_ALIGN
#endif

char	buf[8192+1024];
char	*buf_aligned;

#ifdef	FORCE_ALIGN
#	undef	CHECK_ALIGN
#	undef	OFF_ALIGN
#endif

#ifdef	CHECK_ALIGN
#	undef	FORCE_ALIGN
#	undef	OFF_ALIGN
#endif

#ifdef	OFF_ALIGN
#	undef	FORCE_ALIGN
#	undef	CHECK_ALIGN
#endif


#ifdef	FORCE_ALIGN

#define	ALIGN_short	sizeof (short)
#define	ALIGN_int	sizeof (int)
#define	ALIGN_long	sizeof (long)
#define	ALIGN_longlong	sizeof (long long)
#define	ALIGN_float	sizeof (float)
#define	ALIGN_double	sizeof (double)
#define	ALIGN_ptr	sizeof (char *)

#endif

#ifdef	CHECK_ALIGN

#include <signal.h>
#include <setjmp.h>
LOCAL	jmp_buf	jb;

LOCAL	int	check_align	__PR((int (*)(char*, int), void (*)(char*, int), int));
LOCAL	int	check_short	__PR((char *, int));
LOCAL	int	check_int	__PR((char *, int));
LOCAL	int	check_long	__PR((char *, int));
LOCAL	int	check_longlong	__PR((char *, int));
LOCAL	int	check_float	__PR((char *, int));
LOCAL	int	check_double	__PR((char *, int));
LOCAL	int	check_ptr	__PR((char *, int));

LOCAL	int	speed_check	__PR((char *, void (*)(char*, int), int));
LOCAL	void	speed_short	__PR((char *, int));
LOCAL	void	speed_int	__PR((char *, int));
LOCAL	void	speed_long	__PR((char *, int));
LOCAL	void	speed_longlong	__PR((char *, int));
LOCAL	void	speed_float	__PR((char *, int));
LOCAL	void	speed_double	__PR((char *, int));
LOCAL	void	speed_ptr	__PR((char *, int));

#define	ALIGN_short	check_align(check_short, speed_short, sizeof (short))
#define	ALIGN_int	check_align(check_int, speed_int, sizeof (int))
#define	ALIGN_long	check_align(check_long, speed_long, sizeof (long))
#define	ALIGN_longlong	check_align(check_longlong, speed_longlong, sizeof (long long))
#define	ALIGN_float	check_align(check_float, speed_float, sizeof (float))
#define	ALIGN_double	check_align(check_double, speed_double, sizeof (double))
#define	ALIGN_ptr	check_align(check_ptr, speed_ptr, sizeof (char *))

#endif

#ifdef	OFF_ALIGN

#define	sm_off(s, m)	((int)&((s)0)->m)

LOCAL	int	off_short	__PR((void));
LOCAL	int	off_int		__PR((void));
LOCAL	int	off_long	__PR((void));
LOCAL	int	off_longlong	__PR((void));
LOCAL	int	off_float	__PR((void));
LOCAL	int	off_double	__PR((void));
LOCAL	int	off_ptr		__PR((void));

#define	ALIGN_short	off_short()
#define	ALIGN_int	off_int()
#define	ALIGN_long	off_long()
#define	ALIGN_longlong	off_longlong()
#define	ALIGN_float	off_float()
#define	ALIGN_double	off_double()
#define	ALIGN_ptr	off_ptr()

#endif

LOCAL	void	printmacs	__PR((void));

#ifdef	CHECK_ALIGN
LOCAL	void	sig		__PR((int));

LOCAL void
sig(signo)
	int	signo;
{
	signal(signo, sig);
	longjmp(jb, 1);
}
#endif

#if defined(mc68000) || defined(mc68020)
#define	MIN_ALIGN	2
#else
#define	MIN_ALIGN	2
#endif


#define	min_align(i)	(((i) < MIN_ALIGN) ? MIN_ALIGN : (i))

char	al[] = "alignment value for ";
char	ms[] = "alignment mask  for ";
char	so[] = "sizeof ";
char	sh[] = "short";
char	in[] = "int";
char	lo[] = "long";
char	ll[] = "long long";
char	fl[] = "float";
char	db[] = "double";
char	pt[] = "pointer";

#define	xalign(x, a, m)		( ((char *)(x)) + ( (a) - (((int)(x))&(m))) )

EXPORT int
main(ac, av)
	int	ac;
	char	**av;
{
	char	*p;
	int	i;
	int	s;

#ifdef	CHECK_ALIGN
	signal(SIGBUS, sig);
#endif

	i = ((int)buf) % 1024;
	i = 1024 - i;
	p = &buf[i];
	buf_aligned = p;

#ifdef	DEBUG
	printf("buf: %lX %lX\n",
		(unsigned long)buf, (unsigned long)xalign(buf, 1024, 1023));
#endif

	printf("/*\n");
	printf(" * This file has been generated automatically\n");
	printf(" * by %s\n", sccsid);
	printf(" * do not edit by hand.\n");
	printf(" */\n");
	printf("#ifndef	_UTYPES_H\n");
	printf("#include <utypes.h>\n");
	printf("#endif\n");

	s = sizeof(short);
	i  = ALIGN_short;
	i = min_align(i);
	printf("\n");
	printf("#define	ALIGN_SHORT	%d\t/* %s(%s *)\t*/\n", i, al, sh);
	printf("#define	ALIGN_SMASK	%d\t/* %s(%s *)\t*/\n", i-1, ms, sh);
	printf("#define	SIZE_SHORT	%d\t/* %s(%s)\t\t\t*/\n", s, so, sh);

	s = sizeof(int);
	i  = ALIGN_int;
	i = min_align(i);
	printf("\n");
	printf("#define	ALIGN_INT	%d\t/* %s(%s *)\t\t*/\n", i, al, in);
	printf("#define	ALIGN_IMASK	%d\t/* %s(%s *)\t\t*/\n", i-1, ms, in);
	printf("#define	SIZE_INT	%d\t/* %s(%s)\t\t\t\t*/\n", s, so, in);

	s = sizeof(long);
	i  = ALIGN_long;
	i = min_align(i);
	printf("\n");
	printf("#define	ALIGN_LONG	%d\t/* %s(%s *)\t\t*/\n", i, al, lo);
	printf("#define	ALIGN_LMASK	%d\t/* %s(%s *)\t\t*/\n", i-1, ms, lo);
	printf("#define	SIZE_LONG	%d\t/* %s(%s)\t\t\t*/\n", s, so, lo);

#ifdef	HAVE_LONGLONG
	s = sizeof(long long);
	i  = ALIGN_longlong;
	i = min_align(i);
#endif
	printf("\n");
	printf("#define	ALIGN_LLONG	%d\t/* %s(%s *)\t*/\n", i, al, ll);
	printf("#define	ALIGN_LLMASK	%d\t/* %s(%s *)\t*/\n", i-1, ms, ll);
	printf("#define	SIZE_LLONG	%d\t/* %s(%s)\t\t\t*/\n", s, so, ll);

	s = sizeof(float);
	i  = ALIGN_float;
	i = min_align(i);
	printf("\n");
	printf("#define	ALIGN_FLOAT	%d\t/* %s(%s *)\t*/\n", i, al, fl);
	printf("#define	ALIGN_FMASK	%d\t/* %s(%s *)\t*/\n", i-1, ms, fl);
	printf("#define	SIZE_FLOAT	%d\t/* %s(%s)\t\t\t*/\n", s, so, fl);

	s = sizeof(double);
	i  = ALIGN_double;
	i = min_align(i);
	printf("\n");
	printf("#define	ALIGN_DOUBLE	%d\t/* %s(%s *)\t*/\n", i, al, db);
	printf("#define	ALIGN_DMASK	%d\t/* %s(%s *)\t*/\n", i-1, ms, db);
	printf("#define	SIZE_DOUBLE	%d\t/* %s(%s)\t\t\t*/\n", s, so, db);

	s = sizeof(char *);
	i  = ALIGN_ptr;
	i = min_align(i);
	printf("\n");
	printf("#define	ALIGN_PTR	%d\t/* %s(%s *)\t*/\n", i, al, pt);
	printf("#define	ALIGN_PMASK	%d\t/* %s(%s *)\t*/\n", i-1, ms, pt);
	printf("#define	SIZE_PTR	%d\t/* %s(%s)\t\t\t*/\n", s, so, pt);

	printmacs();
	return (0);
}

LOCAL void
printmacs()
{
printf("\n\n");
printf("/*\n * There used to be a cast to an int but we get a warning from GCC.\n");
printf(" * This warning message from GCC is wrong.\n");
printf(" * Believe me that this macro would even be usable if I would cast to short.\n");
printf(" * In order to avoid this warning, we are now using UIntptr_t\n */\n");
/*printf("\n");*/
/*printf("\n");*/
printf("#define	xaligned(a, s)		((((UIntptr_t)(a)) & s) == 0 )\n");
printf("#define	x2aligned(a, b, s)	(((((UIntptr_t)(a)) | ((UIntptr_t)(b))) & s) == 0 )\n");
printf("\n");
printf("#define	saligned(a)		xaligned(a, ALIGN_SMASK)\n");
printf("#define	s2aligned(a, b)		x2aligned(a, b, ALIGN_SMASK)\n");
printf("\n");
printf("#define	ialigned(a)		xaligned(a, ALIGN_IMASK)\n");
printf("#define	i2aligned(a, b)		x2aligned(a, b, ALIGN_IMASK)\n");
printf("\n");
printf("#define	laligned(a)		xaligned(a, ALIGN_LMASK)\n");
printf("#define	l2aligned(a, b)		x2aligned(a, b, ALIGN_LMASK)\n");
printf("\n");
printf("#define	llaligned(a)		xaligned(a, ALIGN_LLMASK)\n");
printf("#define	ll2aligned(a, b)	x2aligned(a, b, ALIGN_LLMASK)\n");
printf("\n");
printf("#define	faligned(a)		xaligned(a, ALIGN_FMASK)\n");
printf("#define	f2aligned(a, b)		x2aligned(a, b, ALIGN_FMASK)\n");
printf("\n");
printf("#define	daligned(a)		xaligned(a, ALIGN_DMASK)\n");
printf("#define	d2aligned(a, b)		x2aligned(a, b, ALIGN_DMASK)\n");
printf("\n");
printf("#define	paligned(a)		xaligned(a, ALIGN_PMASK)\n");
printf("#define	p2aligned(a, b)		x2aligned(a, b, ALIGN_PMASK)\n");

printf("\n\n");
printf("/*\n * There used to be a cast to an int but we get a warning from GCC.\n");
printf(" * This warning message from GCC is wrong.\n");
printf(" * Believe me that this macro would even be usable if I would cast to short.\n");
printf(" * In order to avoid this warning, we are now using UIntptr_t\n */\n");
printf("#define	xalign(x, a, m)		( ((char *)(x)) + ( (a) - 1 - ((((UIntptr_t)(x))-1)&(m))) )\n");
printf("\n");
printf("#define	salign(x)		xalign((x), ALIGN_SHORT, ALIGN_SMASK)\n");
printf("#define	ialign(x)		xalign((x), ALIGN_INT, ALIGN_IMASK)\n");
printf("#define	lalign(x)		xalign((x), ALIGN_LONG, ALIGN_LMASK)\n");
printf("#define	llalign(x)		xalign((x), ALIGN_LLONG, ALIGN_LLMASK)\n");
printf("#define	falign(x)		xalign((x), ALIGN_FLOAT, ALIGN_FMASK)\n");
printf("#define	dalign(x)		xalign((x), ALIGN_DOUBLE, ALIGN_DMASK)\n");
printf("#define	palign(x)		xalign((x), ALIGN_PTR, ALIGN_PMASK)\n");
}

#ifdef	CHECK_ALIGN
/*
 * Routines to compute the alignement by checking if the assignement
 * causes a bus error.
 * Some systems (e.g. Linux on DEC Aplha) will allow to fetch any
 * type from any address. On these systems we must check the speed
 * because unaligned fetches will take more time.
 */
LOCAL int
check_align(cfunc, sfunc, tsize)
	int	(*cfunc)();
	void	(*sfunc)();
	int	tsize;
{
		 int	calign;
		 int	align;
		 int	tcheck;
		 int	t;
	register int	i;
	register char	*p = buf_aligned;

	for (i=1; i < 128; i++) {
		if (!setjmp(jb)) {
			(cfunc)(p, i);
			break;
		}
	}
#ifdef	DEBUG
	printf("i: %d tsize: %d\n", i, tsize);
#endif
	if (i == tsize)
		return (i);

	align = calign = i;
	tcheck = speed_check(p, sfunc, i);
#ifdef	DEBUG
	printf("tcheck: %d\n", tcheck);
#endif

	for (i = calign*2; i <= tsize; i *= 2) {
		t = speed_check(p, sfunc, i);
#ifdef	DEBUG
		printf("tcheck: %d t: %d i: %d\n", tcheck, t, i);
		printf("tcheck - t: %d ... * 3: %d\n",  (tcheck - t), (tcheck - t) * 3);
#endif
		if (((tcheck - t) > 0) && ((tcheck - t) * 3) > tcheck) {
#ifdef	DEBUG
			printf("kleiner\n");
#endif
			align = i;
			tcheck = t;
		}
	}
	return (align);
}

LOCAL int
check_short(p, i)
	char	*p;
	int	i;
{
	short	*sp;

	sp = (short *)&p[i];
	*sp = 1;
	return (0);
}

LOCAL int
check_int(p, i)
	char	*p;
	int	i;
{
	int	*ip;

	ip = (int *)&p[i];
	*ip = 1;
	return (0);
}

LOCAL int
check_long(p, i)
	char	*p;
	int	i;
{
	long	*lp;

	lp = (long *)&p[i];
	*lp = 1;
	return (0);
}

#ifdef	HAVE_LONGLONG
LOCAL int
check_longlong(p, i)
	char	*p;
	int	i;
{
	long long	*llp;

	llp = (long long *)&p[i];
	*llp = 1;
	return (0);
}
#endif

LOCAL int
check_float(p, i)
	char	*p;
	int	i;
{
	float	*fp;

	fp = (float *)&p[i];
	*fp = 1.0;
	return (0);
}

LOCAL int
check_double(p, i)
	char	*p;
	int	i;
{
	double	*dp;

	dp = (double *)&p[i];
	*dp = 1.0;
	return (0);
}

LOCAL int
check_ptr(p, i)
	char	*p;
	int	i;
{
	char	**pp;

	pp = (char  **)&p[i];
	*pp = (char *)1;
	return (0);
}

/*
 * Routines to compute the alignement by checking the speed of the
 * assignement.
 * Some systems (e.g. Linux on DEC Aplha) will allow to fetch any
 * type from any address. On these systems we must check the speed
 * because unaligned fetches will take more time.
 */
LOCAL void
speed_short(p, n)
	char	*p;
	int	n;
{
	short	*sp;
	int	i;

	sp = (short *)&p[n];

	for (i = 1000000; --i >= 0;)
		*sp = i;
}

LOCAL void
speed_int(p, n)
	char	*p;
	int	n;
{
	int	*ip;
	int	i;

	ip = (int *)&p[n];

	for (i = 1000000; --i >= 0;)
		*ip = i;
}

LOCAL void
speed_long(p, n)
	char	*p;
	int	n;
{
	long	*lp;
	int	i;

	lp = (long *)&p[n];

	for (i = 1000000; --i >= 0;)
		*lp = i;
}

#ifdef	HAVE_LONGLONG
LOCAL void
speed_longlong(p, n)
	char	*p;
	int	n;
{
	long long *llp;
	int	i;

	llp = (long long *)&p[n];

	for (i = 1000000; --i >= 0;)
		*llp = i;
}
#endif

LOCAL void
speed_float(p, n)
	char	*p;
	int	n;
{
	float	*fp;
	int	i;

	fp = (float *)&p[n];

	for (i = 1000000; --i >= 0;)
		*fp = i;
}

LOCAL void
speed_double(p, n)
	char	*p;
	int	n;
{
	double	*dp;
	int	i;

	dp = (double *)&p[n];

	for (i = 1000000; --i >= 0;)
		*dp = i;
}

LOCAL void
speed_ptr(p, n)
	char	*p;
	int	n;
{
	char	**pp;
	int	i;

	pp = (char **)&p[n];

	for (i = 1000000; --i >= 0;)
		*pp = (char *)i;
}

#include <sys/times.h>
LOCAL int
speed_check(p, sfunc, n)
	char	*p;
	void	(*sfunc)();
	int	n;
{
	struct tms tm1;
	struct tms tm2;

	times(&tm1);
	(*sfunc)(p, n);
	times(&tm2);

#ifdef	DEBUG
	printf("t1: %ld\n", (long) tm2.tms_utime-tm1.tms_utime);
#endif

	return ((int) tm2.tms_utime-tm1.tms_utime);
}

#endif	/* CHECK_ALIGN */

#ifdef	OFF_ALIGN
/*
 * Routines to compute the alignement by using the knowledge
 * of the C-compiler.
 * We define a structure and check the padding that has been inserted
 * by the compiler to keep the apropriate type on a properly aligned
 * address.
 */
LOCAL int
off_short()
{
	struct ss {
		char	c;
		short	s;
	} ss;
	ss.c = 0;		/* fool C-compiler */

	return (sm_off(struct ss *, s));
}

LOCAL int
off_int()
{
	struct si {
		char	c;
		int	i;
	} si;
	si.c = 0;		/* fool C-compiler */

	return (sm_off(struct si *, i));
}

LOCAL int
off_long()
{
	struct sl {
		char	c;
		long	l;
	} sl;
	sl.c = 0;		/* fool C-compiler */

	return (sm_off(struct sl *, l));
}

#ifdef	HAVE_LONGLONG
LOCAL int
off_longlong()
{
	struct sll {
		char	c;
		long long	ll;
	} sll;
	sll.c = 0;		/* fool C-compiler */

	return (sm_off(struct sll *, ll));
}
#endif

LOCAL int
off_float()
{
	struct sf {
		char	c;
		float	f;
	} sf;
	sf.c = 0;		/* fool C-compiler */

	return (sm_off(struct sf *, f));
}

LOCAL int
off_double()
{
	struct sd {
		char	c;
		double	d;
	} sd;
	sd.c = 0;		/* fool C-compiler */

	return (sm_off(struct sd *, d));
}

LOCAL int
off_ptr()
{
	struct sp {
		char	c;
		char	*p;
	} sp;
	sp.c = 0;		/* fool C-compiler */

	return (sm_off(struct sp *, p));
}

#endif	/* OFF_ALIGN */