/* * Copyright (c) 2003, 2024, 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 4851638 * @key randomness * @summary Tests for StrictMath.atan2 * @library /test/lib * @build jdk.test.lib.RandomFactory * @build Tests * @build FdlibmTranslit * @build Atan2Tests * @run main Atan2Tests */ import jdk.test.lib.RandomFactory; /** * The tests in ../Math/Atan2Tests.java test properties that should * hold for any atan2 implementation, including the FDLIBM-based one * required for StrictMath.atan2. Therefore, the test cases in * ../Math/Atan2Tests.java are run against both the Math and * StrictMath versions of atan2. The role of this test is to verify * that the FDLIBM atan2 algorithm is being used by running golden * file tests on values that may vary from one conforming atan2 * implementation to another. */ public class Atan2Tests { private Atan2Tests(){} public static void main(String... args) { int failures = 0; failures += testAtan2(); failures += testAgainstTranslit(); if (failures > 0) { System.err.println("Testing atan2 incurred " + failures + " failures."); throw new RuntimeException(); } } private static int testAtan2() { int failures = 0; // Empirical worst-case points in other libraries with larger // worst-case errors than FDLIBM double[][] testCases = { {-0x0.00000000039a2p-1022, 0x0.000fdf02p-1022, -0x1.d0ce6fac85de9p-27}, { 0x1.9173ea8221453p+842, 0x1.8c6f1b4b72f3ap+842, 0x1.9558272cbbdf9p-1}, { 0x1.9cde4ff190e45p+931, 0x1.37d91467e558bp+931, 0x1.d909432d6f9c8p-1}, { 0x1.401ec07d65549p+888, 0x1.3c3976605bb0cp+888, 0x1.95421cda9c65bp-1}, }; for (double[] testCase : testCases) { failures += testAtan2Case(testCase[0], testCase[1], testCase[2]); } return failures; } // Initialize shared random number generator private static java.util.Random random = RandomFactory.getRandom(); /** * Test StrictMath.atan2 against transliteration port of atan2. */ private static int testAgainstTranslit() { int failures = 0; double MIN_VALUE = Double.MIN_VALUE; double MIN_NORM = Double.MIN_NORMAL; double MAX_VALUE = Double.MAX_VALUE; double InfinityD = Double.POSITIVE_INFINITY; double PI = Math.PI; // The exact special cases for infinity, NaN, zero, // etc. inputs are checked in the Math tests. // Test exotic NaN bit patterns double[][] exoticNaNs = { {Double.longBitsToDouble(0x7FF0_0000_0000_0001L), 0.0}, {0.0, Double.longBitsToDouble(0x7FF0_0000_0000_0001L)}, {Double.longBitsToDouble(0xFFF_00000_0000_0001L), 0.0}, {0.0, Double.longBitsToDouble(0xFFF0_0000_0000_0001L)}, {Double.longBitsToDouble(0x7FF_00000_7FFF_FFFFL), 0.0}, {0.0, Double.longBitsToDouble(0x7FF0_7FFF_0000_FFFFL)}, {Double.longBitsToDouble(0xFFF_00000_7FFF_FFFFL), 0.0}, {0.0, Double.longBitsToDouble(0xFFF0_7FFF_0000_FFFFL)}, }; for (double[] exoticNaN: exoticNaNs) { failures += testAtan2Case(exoticNaN[0], exoticNaN[1], FdlibmTranslit.atan2(exoticNaN[0], exoticNaN[1])); } // Probe near decision points in the FDLIBM algorithm. double[][] decisionPoints = { // If x == 1, return atan(y) {0.5, Math.nextDown(1.0)}, {0.5, 1.0}, {0.5, Math.nextUp(1.0)}, { MIN_VALUE, MIN_VALUE}, { MIN_VALUE, -MIN_VALUE}, {-MIN_VALUE, MIN_VALUE}, {-MIN_VALUE, -MIN_VALUE}, { MAX_VALUE, MAX_VALUE}, { MAX_VALUE, -MAX_VALUE}, {-MAX_VALUE, MAX_VALUE}, {-MAX_VALUE, -MAX_VALUE}, { MIN_VALUE, MAX_VALUE}, { MAX_VALUE, MIN_VALUE}, {-MIN_VALUE, MAX_VALUE}, {-MAX_VALUE, MIN_VALUE}, {MIN_VALUE, -MAX_VALUE}, {MAX_VALUE, -MIN_VALUE}, {-MIN_VALUE, -MAX_VALUE}, {-MAX_VALUE, -MIN_VALUE}, }; for (double[] decisionPoint: decisionPoints) { failures += testAtan2Case(decisionPoint[0], decisionPoint[1], FdlibmTranslit.atan2(decisionPoint[0], decisionPoint[1])); } // atan2 looks at the ratio y/x and executes different code // paths accordingly: tests for 2^60 and 2^-60. double y = 1.0; double x = 0x1.0p60; double increment_x = Math.ulp(x); double increment_y = Math.ulp(y); y = y - 128*increment_y; x = x - 128*increment_x; for (int i = 0; i < 256; i++, x += increment_x) { for (int j = 0; j < 256; j++, y += increment_y) { failures += testAtan2Case( y, x, FdlibmTranslit.atan2( y, x)); failures += testAtan2Case(-y, x, FdlibmTranslit.atan2(-y, x)); failures += testAtan2Case( y, -x, FdlibmTranslit.atan2( y, -x)); failures += testAtan2Case(-y, -x, FdlibmTranslit.atan2(-y, -x)); failures += testAtan2Case( 2.0*y, 2.0*x, FdlibmTranslit.atan2( 2.0*y, 2.0*x)); failures += testAtan2Case(-2.0*y, 2.0*x, FdlibmTranslit.atan2(-2.0*y, 2.0*x)); failures += testAtan2Case( 2.0*y, -2.0*x, FdlibmTranslit.atan2( 2.0*y, -2.0*x)); failures += testAtan2Case(-2.0*y, -2.0*x, FdlibmTranslit.atan2(-2.0*y, -2.0*x)); failures += testAtan2Case( 0.5*y, 0.5*x, FdlibmTranslit.atan2( 0.5*y, 0.5*x)); failures += testAtan2Case(-0.5*y, 0.5*x, FdlibmTranslit.atan2(-0.5*y, 0.5*x)); failures += testAtan2Case( 0.5*y, -0.5*x, FdlibmTranslit.atan2( 0.5*y, -0.5*x)); failures += testAtan2Case(-0.5*y, -0.5*x, FdlibmTranslit.atan2(-0.5*y, -0.5*x)); // Switch argument position failures += testAtan2Case( x, y, FdlibmTranslit.atan2( x, y)); failures += testAtan2Case(-x, y, FdlibmTranslit.atan2(-x, y)); failures += testAtan2Case( x, -y, FdlibmTranslit.atan2( x, -y)); failures += testAtan2Case(-x, -y, FdlibmTranslit.atan2(-x, -y)); failures += testAtan2Case( 0.5*x, 0.5*y, FdlibmTranslit.atan2( 0.5*x, 0.5*y)); failures += testAtan2Case(-0.5*x, 0.5*y, FdlibmTranslit.atan2(-0.5*x, 0.5*y)); failures += testAtan2Case( 0.5*x, -0.5*y, FdlibmTranslit.atan2( 0.5*x, -0.5*y)); failures += testAtan2Case(-0.5*x, -0.5*y, FdlibmTranslit.atan2(-0.5*x, -0.5*y)); } } // Check random values for (int k = 0; k < 200; k++ ) { y = random.nextDouble(); x = random.nextDouble(); failures += testAtan2Case(y, x, FdlibmTranslit.atan2(y, x)); } return failures; } private static int testAtan2Case(double input1, double input2, double expected) { int failures = 0; failures += Tests.test("StrictMath.atan2(double)", input1, input2, StrictMath::atan2, expected); return failures; } }