Mercurial > hg > graal-compiler
view test/compiler/loopopts/TestLogSum.java @ 22266:e743cde3ff3a
Add ConstantStackCastTest.
author | Josef Eisl <josef.eisl@jku.at> |
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date | Tue, 21 Jul 2015 10:55:01 +0200 |
parents | 4077c61b03a0 |
children |
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/* * Copyright (c) 2014, 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 8046516 * @summary Segmentation fault in JVM (easily reproducible) * @run main/othervm -XX:-TieredCompilation -Xbatch TestLogSum * @author jackkamm@gmail.com */ import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; public class TestLogSum { public static void main(String[] args) { double sum; for (int i = 0; i < 6; i++) { for (int n = 2; n < 30; n++) { for (int j = 1; j <= n; j++) { for (int k = 1; k <= j; k++) { // System.out.println(computeSum(k, j)); sum = computeSum(k, j); } } } } } private static Map<List<Integer>, Double> cache = new HashMap<List<Integer>, Double>(); public static double computeSum(int x, int y) { List<Integer> key = Arrays.asList(new Integer[] {x, y}); if (!cache.containsKey(key)) { // explicitly creating/updating a double[] array, instead of using the LogSumArray wrapper object, will prevent the error LogSumArray toReturn = new LogSumArray(x); // changing loop indices will prevent the error // in particular, for(z=0; z<x-1; z++), and then using z+1 in place of z, will not produce error for (int z = 1; z < x+1; z++) { double logSummand = Math.log(z + x + y); toReturn.addLogSummand(logSummand); } // returning the value here without cacheing it will prevent the segfault cache.put(key, toReturn.retrieveLogSum()); } return cache.get(key); } /* * Given a bunch of logarithms log(X),log(Y),log(Z),... * This class is used to compute the log of the sum, log(X+Y+Z+...) */ private static class LogSumArray { private double[] logSummandArray; private int currSize; private double maxLogSummand; public LogSumArray(int maxEntries) { this.logSummandArray = new double[maxEntries]; this.currSize = 0; this.maxLogSummand = Double.NEGATIVE_INFINITY; } public void addLogSummand(double logSummand) { logSummandArray[currSize] = logSummand; currSize++; // removing this line will prevent the error maxLogSummand = Math.max(maxLogSummand, logSummand); } public double retrieveLogSum() { if (maxLogSummand == Double.NEGATIVE_INFINITY) return Double.NEGATIVE_INFINITY; assert currSize <= logSummandArray.length; double factorSum = 0; for (int i = 0; i < currSize; i++) { factorSum += Math.exp(logSummandArray[i] - maxLogSummand); } return Math.log(factorSum) + maxLogSummand; } } }