001/*
002 * Copyright (c) 2007, 2012, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023// Checkstyle: stop
024
025package com.oracle.graal.jtt.hotpath;
026
027import org.junit.*;
028
029import com.oracle.graal.jtt.*;
030
031/*
032 */
033public class HP_series extends JTTTest {
034
035    public static double test(int count) {
036        final int arrayRows = count;
037        final double[][] testArray = new double[2][arrayRows];
038        double omega; // Fundamental frequency.
039        testArray[0][0] = TrapezoidIntegrate(0.0, // Lower bound.
040                        2.0, // Upper bound.
041                        1000, // # of steps.
042                        0.0, // No omega*n needed.
043                        0) / 2.0; // 0 = term A[0].
044        omega = 3.1415926535897932;
045        for (int i = 1; i < arrayRows; i++) {
046            testArray[0][i] = TrapezoidIntegrate(0.0, 2.0, 1000, omega * i, 1); // 1 = cosine
047            // term.
048            testArray[1][i] = TrapezoidIntegrate(0.0, 2.0, 1000, omega * i, 2); // 2 = sine
049            // term.
050        }
051        final double ref[][] = {{2.8729524964837996, 0.0}, {1.1161046676147888, -1.8819691893398025}, {0.34429060398168704, -1.1645642623320958}, {0.15238898702519288, -0.8143461113044298}};
052        double error = 0.0;
053        double sum = 0.0;
054        for (int i = 0; i < 4; i++) {
055            for (int j = 0; j < 2; j++) {
056                error += Math.abs(testArray[j][i] - ref[i][j]);
057                sum += testArray[j][i];
058            }
059        }
060        return sum + error;
061    }
062
063    private static double TrapezoidIntegrate(double x0, // Lower bound.
064                    double x1, // Upper bound.
065                    int ns, // # of steps.
066                    double omegan, // omega * n.
067                    int select) // Term type.
068    {
069        int nsteps = ns;
070        double x; // Independent variable.
071        double dx; // Step size.
072        double rvalue; // Return value.
073
074        x = x0;
075        dx = (x1 - x0) / nsteps;
076        rvalue = thefunction(x0, omegan, select) / 2.0;
077        if (nsteps != 1) {
078            --nsteps; // Already done 1 step.
079            while (--nsteps > 0) {
080                x += dx;
081                rvalue += thefunction(x, omegan, select);
082            }
083        }
084        rvalue = (rvalue + thefunction(x1, omegan, select) / 2.0) * dx;
085        return (rvalue);
086    }
087
088    private static double thefunction(double x, // Independent variable.
089                    double omegan, // Omega * term.
090                    int select) // Choose type.
091    {
092        switch (select) {
093            case 0:
094                return (Math.pow(x + 1.0, x));
095            case 1:
096                return (Math.pow(x + 1.0, x) * Math.cos(omegan * x));
097            case 2:
098                return (Math.pow(x + 1.0, x) * Math.sin(omegan * x));
099        }
100        return (0.0);
101    }
102
103    /*
104     * This test is sensible to the implementation of Math.pow, cos and sin. Since for these
105     * functions, the specs says "The computed result must be within 1 ulp of the exact result",
106     * different implementation may return different results. The 11 ulp delta allowed for test(100)
107     * tries to account for that but is not guaranteed to work forever.
108     */
109    @Ignore("failure-prone because of the variabiliy of pow/cos/sin")
110    @Test
111    public void run0() throws Throwable {
112        double expected = 0.6248571921291398d;
113        runTestWithDelta(11 * Math.ulp(expected), "test", 100);
114    }
115
116}