jdk-24/test/jdk/java/lang/StrictMath/Atan2Tests.java
Joe Darcy fcaf871408 8302028: Port fdlibm atan2 to Java
Reviewed-by: bpb
2023-02-22 22:49:59 +00:00

192 lines
7.5 KiB
Java

/*
* Copyright (c) 2003, 2023, 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 += testAgainstTranslit();
if (failures > 0) {
System.err.println("Testing atan2 incurred "
+ failures + " failures.");
throw new RuntimeException();
}
}
// 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;
}
}