| /* |
| * Copyright (c) 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.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("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(" (" + 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 = ((long)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); |
| } |
| |
| } |