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/*
* Copyright 2009 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/**
* @test
* @bug 6603011
* @summary long/int division by constant
*
* @run main/othervm -Xcomp -Xbatch -XX:-Inline Test
*/
//
// -XX:-Inline is essential to this test so that verification functions
// divi, modi, divl and modl generate "plain" divides.
// -Xcomp -Xbatch are also useful to ensure the full range of
// dividend and divisor combinations are tested
//
import java.net.*;
class s {
static int divi(int dividend, int divisor) { return dividend / divisor; }
static int modi(int dividend, int divisor) { return dividend % divisor; }
static long divl(long dividend, long divisor) { return dividend / divisor; }
static long modl(long dividend, long divisor) { return dividend % divisor; }
}
public class Test implements Runnable {
// Report verbose messages on failure; turn off to suppress
// too much output with gross numbers of failures.
static final boolean VERBOSE = true;
// Initailize DIVISOR so that it is final in this class.
static final int DIVISOR;
static {
int value = 0;
try {
value = Integer.decode(System.getProperty("divisor"));
} catch (Throwable e) {
}
DIVISOR = value;
}
// The methods of interest. We want the JIT to compile these
// and convert the divide into a multiply.
public int divbyI (int dividend) { return dividend / DIVISOR; }
public int modbyI (int dividend) { return dividend % DIVISOR; }
public long divbyL (long dividend) { return dividend / DIVISOR; }
public long modbyL (long dividend) { return dividend % DIVISOR; }
public int divisor() { return DIVISOR; }
public boolean checkI (int dividend) {
int quo = divbyI(dividend);
int rem = modbyI(dividend);
int quo0 = s.divi(dividend, divisor());
int rem0 = s.modi(dividend, divisor());
if (quo != quo0 || rem != rem0) {
if (VERBOSE) {
System.out.println("Computed: " + dividend + " / " + divisor() + " = " +
quo + ", " + dividend + " % " + divisor() + " = " + rem );
System.out.println("expected: " + dividend + " / " + divisor() + " = " +
quo0 + ", " + dividend + " % " + divisor() + " = " + rem0);
// Report sign of rem failure
if (rem != 0 && (rem ^ dividend) < 0) {
System.out.println(" rem & dividend have different signs");
}
// Report range of rem failure
if (java.lang.Math.abs(rem) >= java.lang.Math.abs(divisor())) {
System.out.println(" remainder out of range");
}
// Report quo/rem identity relationship failure
if ((quo * divisor()) + rem != dividend) {
System.out.println(" quotien/remainder invariant broken");
}
}
return false;
}
return true;
}
public boolean checkL (long dividend) {
long quo = divbyL(dividend);
long rem = modbyL(dividend);
long quo0 = s.divl(dividend, divisor());
long rem0 = s.modl(dividend, divisor());
if (quo != quo0 || rem != rem0) {
if (VERBOSE) {
System.out.println(" " + dividend + " / " + divisor() + " = " +
quo + ", " + dividend + " % " + divisor() + " = " + rem);
// Report sign of rem failure
if (rem != 0 && (rem ^ dividend) < 0) {
System.out.println(" rem & dividend have different signs");
}
// Report range of rem failure
if (java.lang.Math.abs(rem) >= java.lang.Math.abs(divisor())) {
System.out.println(" remainder out of range");
}
// Report quo/rem identity relationship failure
if ((quo * divisor()) + rem != dividend) {
System.out.println(" (" + quo + " * " + divisor() + ") + " + rem + " != "
+ dividend);
}
}
return false;
}
return true;
}
public void run() {
// Don't try to divide by zero
if (divisor() == 0) return;
// Range of dividends to check. Try dividends from start to end
// inclusive, as well as variations on those values as shifted
// left.
int start = -1024;
int end = 1024;
// Test int division using a variety of dividends.
int wrong = 0;
int total = 0;
outerloop:
for (int i = start; i <= end; i++) {
for (int s = 0; s < 32; s += 4) {
total++;
int dividend = i << s;
if (!checkI(dividend)) {
wrong++;
// Stop on the first failure
// break outerloop;
}
}
}
if (wrong > 0) {
System.out.println("divisor " + divisor() + ": " +
wrong + "/" + total + " wrong int divisions");
}
// Test long division using a variety of dividends.
wrong = 0;
total = 0;
outerloop:
for (int i = start; i <= end; i++) {
for (int s = 0; s < 64; s += 4) {
total++;
long dividend = i << s;
if (!checkL(dividend)) {
wrong++;
// Stop on the first failure
// break outerloop;
}
}
}
if (wrong > 0) {
System.out.println("divisor " + divisor() + ": " +
wrong + "/" + total + " wrong long divisions");
}
}
// Reload this class with the "divisor" property set to the input parameter.
// This allows the JIT to see q.DIVISOR as a final constant, and change
// any divisions or mod operations into multiplies.
public static void test_divisor(int divisor,
URLClassLoader apploader) throws Exception {
System.setProperty("divisor", "" + divisor);
ClassLoader loader = new URLClassLoader(apploader.getURLs(),
apploader.getParent());
Class c = loader.loadClass("Test");
Runnable r = (Runnable)c.newInstance();
r.run();
}
public static void main(String[] args) throws Exception {
Class cl = Class.forName("Test");
URLClassLoader apploader = (URLClassLoader)cl.getClassLoader();
// Test every divisor between -100 and 100.
for (int i = -100; i <= 100; i++) {
test_divisor(i, apploader);
}
// Try a few divisors outside the typical range.
// The values below have been observed in rt.jar.
test_divisor(101, apploader);
test_divisor(400, apploader);
test_divisor(1000, apploader);
test_divisor(3600, apploader);
test_divisor(9973, apploader);
test_divisor(86400, apploader);
test_divisor(1000000, apploader);
}
}
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