--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/Math/HypotTests.java Mon Jan 26 19:49:26 2009 -0800
@@ -0,0 +1,245 @@
+/*
+ * Copyright 2003 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test
+ * @bug 4851638 4939441
+ * @summary Tests for {Math, StrictMath}.hypot
+ * @author Joseph D. Darcy
+ */
+
+import sun.misc.DoubleConsts;
+import sun.misc.FpUtils;
+
+public class HypotTests {
+ private HypotTests(){}
+
+ static final double infinityD = Double.POSITIVE_INFINITY;
+ static final double NaNd = Double.NaN;
+
+ /**
+ * Given integers m and n, assuming m < n, the triple (n^2 - m^2,
+ * 2mn, and n^2 + m^2) is a Pythagorean triple with a^2 + b^2 =
+ * c^2. This methods returns a long array holding the Pythagorean
+ * triple corresponding to the inputs.
+ */
+ static long [] pythagoreanTriple(int m, int n) {
+ long M = m;
+ long N = n;
+ long result[] = new long[3];
+
+
+ result[0] = Math.abs(M*M - N*N);
+ result[1] = Math.abs(2*M*N);
+ result[2] = Math.abs(M*M + N*N);
+
+ return result;
+ }
+
+ static int testHypot() {
+ int failures = 0;
+
+ double [][] testCases = {
+ // Special cases
+ {infinityD, infinityD, infinityD},
+ {infinityD, 0.0, infinityD},
+ {infinityD, 1.0, infinityD},
+ {infinityD, NaNd, infinityD},
+ {NaNd, NaNd, NaNd},
+ {0.0, NaNd, NaNd},
+ {1.0, NaNd, NaNd},
+ {Double.longBitsToDouble(0x7FF0000000000001L), 1.0, NaNd},
+ {Double.longBitsToDouble(0xFFF0000000000001L), 1.0, NaNd},
+ {Double.longBitsToDouble(0x7FF8555555555555L), 1.0, NaNd},
+ {Double.longBitsToDouble(0xFFF8555555555555L), 1.0, NaNd},
+ {Double.longBitsToDouble(0x7FFFFFFFFFFFFFFFL), 1.0, NaNd},
+ {Double.longBitsToDouble(0xFFFFFFFFFFFFFFFFL), 1.0, NaNd},
+ {Double.longBitsToDouble(0x7FFDeadBeef00000L), 1.0, NaNd},
+ {Double.longBitsToDouble(0xFFFDeadBeef00000L), 1.0, NaNd},
+ {Double.longBitsToDouble(0x7FFCafeBabe00000L), 1.0, NaNd},
+ {Double.longBitsToDouble(0xFFFCafeBabe00000L), 1.0, NaNd},
+ };
+
+ for(int i = 0; i < testCases.length; i++) {
+ failures += testHypotCase(testCases[i][0], testCases[i][1],
+ testCases[i][2]);
+ }
+
+ // Verify hypot(x, 0.0) is close to x over the entire exponent
+ // range.
+ for(int i = DoubleConsts.MIN_SUB_EXPONENT;
+ i <= DoubleConsts.MAX_EXPONENT;
+ i++) {
+ double input = FpUtils.scalb(2, i);
+ failures += testHypotCase(input, 0.0, input);
+ }
+
+
+ // Test Pythagorean triples
+
+ // Small ones
+ for(int m = 1; m < 10; m++) {
+ for(int n = m+1; n < 11; n++) {
+ long [] result = pythagoreanTriple(m, n);
+ failures += testHypotCase(result[0], result[1], result[2]);
+ }
+ }
+
+ // Big ones
+ for(int m = 100000; m < 100100; m++) {
+ for(int n = m+100000; n < 200200; n++) {
+ long [] result = pythagoreanTriple(m, n);
+ failures += testHypotCase(result[0], result[1], result[2]);
+ }
+ }
+
+ // Approaching overflow tests
+
+ /*
+ * Create a random value r with an large-ish exponent. The
+ * result of hypot(3*r, 4*r) should be approximately 5*r. (The
+ * computation of 4*r is exact since it just changes the
+ * exponent). While the exponent of r is less than or equal
+ * to (MAX_EXPONENT - 3), the computation should not overflow.
+ */
+ java.util.Random rand = new java.util.Random();
+ for(int i = 0; i < 1000; i++) {
+ double d = rand.nextDouble();
+ // Scale d to have an exponent equal to MAX_EXPONENT -15
+ d = FpUtils.scalb(d, DoubleConsts.MAX_EXPONENT
+ -15 - FpUtils.ilogb(d));
+ for(int j = 0; j <= 13; j += 1) {
+ failures += testHypotCase(3*d, 4*d, 5*d, 2.5);
+ d *= 2.0; // increase exponent by 1
+ }
+ }
+
+ // Test for monotonicity failures. Fix one argument and test
+ // two numbers before and two numbers after each chosen value;
+ // i.e.
+ //
+ // pcNeighbors[] =
+ // {nextDown(nextDown(pc)),
+ // nextDown(pc),
+ // pc,
+ // nextUp(pc),
+ // nextUp(nextUp(pc))}
+ //
+ // and we test that hypot(pcNeighbors[i]) <= hypot(pcNeighbors[i+1])
+ {
+ double pcNeighbors[] = new double[5];
+ double pcNeighborsHypot[] = new double[5];
+ double pcNeighborsStrictHypot[] = new double[5];
+
+
+ for(int i = -18; i <= 18; i++) {
+ double pc = FpUtils.scalb(1.0, i);
+
+ pcNeighbors[2] = pc;
+ pcNeighbors[1] = FpUtils.nextDown(pc);
+ pcNeighbors[0] = FpUtils.nextDown(pcNeighbors[1]);
+ pcNeighbors[3] = FpUtils.nextUp(pc);
+ pcNeighbors[4] = FpUtils.nextUp(pcNeighbors[3]);
+
+ for(int j = 0; j < pcNeighbors.length; j++) {
+ pcNeighborsHypot[j] = Math.hypot(2.0, pcNeighbors[j]);
+ pcNeighborsStrictHypot[j] = StrictMath.hypot(2.0, pcNeighbors[j]);
+ }
+
+ for(int j = 0; j < pcNeighborsHypot.length-1; j++) {
+ if(pcNeighborsHypot[j] > pcNeighborsHypot[j+1] ) {
+ failures++;
+ System.err.println("Monotonicity failure for Math.hypot on " +
+ pcNeighbors[j] + " and " +
+ pcNeighbors[j+1] + "\n\treturned " +
+ pcNeighborsHypot[j] + " and " +
+ pcNeighborsHypot[j+1] );
+ }
+
+ if(pcNeighborsStrictHypot[j] > pcNeighborsStrictHypot[j+1] ) {
+ failures++;
+ System.err.println("Monotonicity failure for StrictMath.hypot on " +
+ pcNeighbors[j] + " and " +
+ pcNeighbors[j+1] + "\n\treturned " +
+ pcNeighborsStrictHypot[j] + " and " +
+ pcNeighborsStrictHypot[j+1] );
+ }
+
+
+ }
+
+ }
+ }
+
+
+ return failures;
+ }
+
+ static int testHypotCase(double input1, double input2, double expected) {
+ return testHypotCase(input1,input2, expected, 1);
+ }
+
+ static int testHypotCase(double input1, double input2, double expected,
+ double ulps) {
+ int failures = 0;
+ if (expected < 0.0) {
+ throw new AssertionError("Result of hypot must be greater than " +
+ "or equal to zero");
+ }
+
+ // Test Math and StrictMath methods with no inputs negated,
+ // each input negated singly, and both inputs negated. Also
+ // test inputs in reversed order.
+
+ for(int i = -1; i <= 1; i+=2) {
+ for(int j = -1; j <= 1; j+=2) {
+ double x = i * input1;
+ double y = j * input2;
+ failures += Tests.testUlpDiff("Math.hypot", x, y,
+ Math.hypot(x, y), expected, ulps);
+ failures += Tests.testUlpDiff("Math.hypot", y, x,
+ Math.hypot(y, x ), expected, ulps);
+
+ failures += Tests.testUlpDiff("StrictMath.hypot", x, y,
+ StrictMath.hypot(x, y), expected, ulps);
+ failures += Tests.testUlpDiff("StrictMath.hypot", y, x,
+ StrictMath.hypot(y, x), expected, ulps);
+ }
+ }
+
+ return failures;
+ }
+
+ public static void main(String argv[]) {
+ int failures = 0;
+
+ failures += testHypot();
+
+ if (failures > 0) {
+ System.err.println("Testing the hypot incurred "
+ + failures + " failures.");
+ throw new RuntimeException();
+ }
+ }
+
+}