testcases/misc/math/fptests/fptest01.c

/*
 *
 *   Copyright (c) International Business Machines  Corp., 2002
 *
 *   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 of the License, 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;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/* Group Bull & IBM Corporation */
/* 11/20/2002	Port to LTP	robbiew@us.ibm.com */
/*                                               jacky.malcles@bull.net */
/* IBM Corporation */
/* 06/30/2001	Port to Linux	nsharoff@us.ibm.com */

/*
 * fptest01.c -- Floating point test.
 *
 * It is taken from a benchmark called "barsim".
 *
 * If the computation arrives at the expected values this routine
 * prints a "passed" message and exits 0.  If an incorrect value is
 * computed a "failed" message is printed and the routine exits 1.
 */

#include <stdio.h>
#include <errno.h>
#include <math.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define MAGIC1	1632.796126
#define DIFF1	0.001
#define MAGIC2	0.777807
#define DIFF2	0.001
#define EVENTMX	256
#define BIG 1.e50
#define FALSE 0
#define TRUE  1
#define TRYCRIT   1
#define ENTERCRIT 2
#define LEAVECRIT 3
#define ATBARRIER 4
#define ENTERWORK 5
#define LEAVEWORK 6
#define NULLEVENT 999

/** LTP Port **/
#include "test.h"
#include "usctest.h"

char *TCID="fptest01";          /* Test program identifier.    */
int TST_TOTAL=1;                /* Total number of test cases. */
/**************/

int init();
int doevent();
int term();
int addevent();
double gauss();
void   gaussinit();
struct event {
	int proc;
	int type;
	double time;
	};

struct event eventtab[EVENTMX];
struct event rtrevent;
int waiting[EVENTMX];	/* array of waiting processors */
int nwaiting;		/* number of waiting processors */
double global_time;		/* global clock */
double lsttime;		/* time used for editing */
double dtc, dts, alpha;	/* timing parameters */
int nproc;		/* number of processors */
int barcnt;		/* number of processors ATBARRIER */
int ncycle;		/* number of cycles completed */
int ncycmax;		/* number of cycles to run */
int critfree;		/* TRUE if critical section not occupied */
int gcount;		/* # calls to gauss */

struct event *nextevent();

int
main(int argc, char **argv)
{
	struct event *ev;

	nproc = 128;
	ncycmax = 10;
	dtc = 0.01;
	dts = 0.0;
	alpha = 0.1;

	init();

	while ((ev=nextevent()) != NULL) {
		doevent(ev);
	}

	term();
	tst_resm(TPASS,"PASS");
	tst_exit();
}

/*
	initialize all processes to "entering work section"
*/
int
init()
{
	int p;
	double dtw, dtwsig;

	ncycle=0;
	global_time=0;
	lsttime=0;
	barcnt=0;
	nwaiting=0;
	critfree=TRUE;

	dtw=1./nproc;		/* mean process work time */
	dtwsig=dtw*alpha;	/* std deviation of work time */
	gaussinit(dtw,dtwsig);

	for (p=1; p<=nproc; p++) {
		eventtab[p].type = NULLEVENT;
	}

	for (p=1; p<=nproc; p++) {
		addevent(ENTERWORK,p,global_time);
	}

	return(0);
}
/*
	print edit quantities
*/
int
term()
{
	double avgspd;
	double t_total = 0.0;
	double v;
	int i;

	for (i=0; i < nproc; i++)
		t_total += eventtab[i].time;

	avgspd=ncycle/global_time;

	v = t_total - MAGIC1;
	if (v < 0.0)
		v *= -1.0;

	if (v > DIFF1) {
		tst_resm(TFAIL,"FAIL");
		v = t_total - MAGIC1;
		tst_resm(TINFO,"t_total = %.15f\n", t_total);
		tst_resm(TINFO,"expected  %.15f\n", MAGIC1);
		tst_resm(TINFO,"diff = %.15f\n", v);
		tst_exit();
	}

	v = avgspd - MAGIC2;
	if (v < 0.0)
		v *= -1.0;

	if (v > DIFF2) {
		tst_resm(TFAIL,"FAIL");
		v = avgspd - MAGIC2;
		tst_resm(TINFO,"avgspd  = %.15f\n", avgspd);
		tst_resm(TINFO,"expected  %.15f\n", MAGIC2);
		tst_resm(TINFO,"diff = %.15f\n", v);
		tst_exit();
	}
	return(0);
}
/*
	add an event to the event queue
*/
int
addevent(int type,int proc, double t)
{
	int i;
	int ok=FALSE;

	for (i=1; i<=nproc; i++) {
		if (eventtab[i].type==NULLEVENT) {
			eventtab[i].type=type;
			eventtab[i].proc=proc;
			eventtab[i].time=t;
			ok=TRUE;
			break;
		}
	}
	if (ok)
		return(0);
	else
		tst_brkm(TBROK, NULL, "No room for event");
	return(0);
}
/*
	get earliest event in event queue
*/
struct event *nextevent()
{
	double mintime=BIG;
	int imin=0;
	int i;

	for (i=1; i<=nproc; i++) {
		if (eventtab[i].type != NULLEVENT &&
		    eventtab[i].time<mintime) {
			imin=i;
			mintime=eventtab[i].time;
		}
	}

	if (imin) {
		rtrevent.type = eventtab[imin].type;
		rtrevent.proc = eventtab[imin].proc;
		rtrevent.time = eventtab[imin].time;
		eventtab[imin].type=NULLEVENT;
		return(&rtrevent);
	} else
		return((struct event *)NULL);
}
/*
	add a processor to the waiting queue
*/
int
addwaiting(p)
int p;
{
	waiting[++nwaiting]=p;
	return(0);
}
/*
	remove the next processor from the waiting queue
*/
int
getwaiting()
{
	if (nwaiting)
		return(waiting[nwaiting--]);
	else
		return(0);
}
double dtcrit()
{
	return(dtc);
}
double dtspinoff()
{
	return(dts);
}
double dtwork()
{
	return(gauss());
}
/*
	take the action prescribed by 'ev', update the clock, and
	generate any subsequent events
*/
int
doevent(ev)
struct event *ev;
{
	double nxttime;
	int i, p, proc;

	global_time = ev->time;
	proc = ev->proc;

	switch (ev->type) {
	case TRYCRIT:
		if (critfree==TRUE)
			addevent(ENTERCRIT,proc,global_time);
		else
			addwaiting(proc);
		break;
	case ENTERCRIT:
		critfree = FALSE;
		nxttime=global_time+dtcrit();
		addevent(LEAVECRIT,proc,nxttime);
		break;
	case LEAVECRIT:
		critfree = TRUE;
		addevent(ATBARRIER,proc,global_time);
		if ((p=getwaiting())!=0) {
			nxttime=global_time;
			addevent(ENTERCRIT,p,nxttime);
		}
		break;
	case ATBARRIER:
		barcnt++;
		if (barcnt==nproc) {
			nxttime=global_time;
			for (i=1; i<=nproc; i++) {
				nxttime+=dtspinoff();
				addevent(ENTERWORK,i,nxttime);
			}
			barcnt=0;
			ncycle++;
		}
		break;
	case ENTERWORK:
		nxttime=global_time+dtwork();
		if (ncycle<ncycmax)
			addevent(LEAVEWORK,proc,nxttime);
		break;
	case LEAVEWORK:
		addevent(TRYCRIT,proc,global_time);
		break;
	default:
		tst_brkm(TBROK, NULL, "Illegal event");
		break;
	}
	return(0);
}

static int alternator=1;
static double mean;
static double stdev;
static double u1,u2;
static double twopi;

void gaussinit(double m, double s)
{
	mean=m;
	stdev=s;
	twopi=2.*acos((double)-1.0);
	u1 = twopi / 400.0;
	u2 = twopi / 500.0;
}

double gauss()
{
	double x1,x2;

	gcount++;

	u1 += u2;
	if (u1 > 0.99)
		u1 = twopi / 500.0;
	u2 += u1;
	if (u2 > 0.99)
		u2 = twopi / 400.0;

	if (alternator==1) {
		alternator = -1;
		x1 = sqrt(-2.0*log(u1))*cos(twopi*u2);
		return(mean + stdev*x1);
	} else {
		alternator = 1;
		x2 = sqrt(-2.0*log(u1))*sin(twopi*u2);
		return(mean + stdev*x2);
	}
}