test/java/lang/Math/RoundTests.java

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rev 7994 : 8010430: Math.round has surprising behavior for odd values of ulp 1
Summary: If the effective floating point exponent is zero return the significand including the implicit 1-bit.
Reviewed-by: bpb, darcy, gls
Contributed-by: Dmitry Nadezhin <dmitry.nadezhin@oracle.com>

*** 1,7 **** /* ! * Copyright (c) 2011, 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. --- 1,7 ---- /* ! * Copyright (c) 2011, 2013, 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.
*** 21,39 **** * questions. */ /* * @test ! * @bug 6430675 * @summary Check for correct implementation of {Math, StrictMath}.round */ public class RoundTests { public static void main(String... args) { int failures = 0; failures += testNearFloatHalfCases(); failures += testNearDoubleHalfCases(); if (failures > 0) { System.err.println("Testing {Math, StrictMath}.round incurred " + failures + " failures."); throw new RuntimeException(); --- 21,41 ---- * questions. */ /* * @test ! * @bug 6430675 8010430 * @summary Check for correct implementation of {Math, StrictMath}.round */ public class RoundTests { public static void main(String... args) { int failures = 0; failures += testNearFloatHalfCases(); failures += testNearDoubleHalfCases(); + failures += testUnityULPCases(); + failures += testSpecialCases(); if (failures > 0) { System.err.println("Testing {Math, StrictMath}.round incurred " + failures + " failures."); throw new RuntimeException();
*** 93,98 **** --- 95,165 ---- failures += Tests.test("Math.round", input, Math.round(input), expected); failures += Tests.test("StrictMath.round", input, StrictMath.round(input), expected); return failures; } + + private static int testUnityULPCases() { + int failures = 0; + for (float sign : new float[]{-1, 1}) { + for (float v1 : new float[]{1 << 23, 1 << 24}) { + for (int k = -5; k <= 5; k++) { + float value = (v1 + k) * sign; + float actual = Math.round(value); + failures += Tests.test("Math.round", value, actual, value); + } + } + } + + if (failures != 0) { + System.out.println(); + } + + for (double sign : new double[]{-1, 1}) { + for (double v1 : new double[]{1L << 52, 1L << 53}) { + for (int k = -5; k <= 5; k++) { + double value = (v1 + k) * sign; + double actual = Math.round(value); + failures += Tests.test("Math.round", value, actual, value); + } + } + } + + return failures; + } + + private static int testSpecialCases() { + int failures = 0; + + failures += Tests.test("Math.round", Float.NaN, Math.round(Float.NaN), 0.0F); + failures += Tests.test("Math.round", Float.POSITIVE_INFINITY, + Math.round(Float.POSITIVE_INFINITY), Integer.MAX_VALUE); + failures += Tests.test("Math.round", Float.NEGATIVE_INFINITY, + Math.round(Float.NEGATIVE_INFINITY), Integer.MIN_VALUE); + failures += Tests.test("Math.round", -(float)Integer.MIN_VALUE, + Math.round(-(float)Integer.MIN_VALUE), Integer.MAX_VALUE); + failures += Tests.test("Math.round", (float) Integer.MIN_VALUE, + Math.round((float) Integer.MIN_VALUE), Integer.MIN_VALUE); + failures += Tests.test("Math.round", 0F, Math.round(0F), 0.0F); + failures += Tests.test("Math.round", Float.MIN_VALUE, + Math.round(Float.MIN_VALUE), 0.0F); + failures += Tests.test("Math.round", -Float.MIN_VALUE, + Math.round(-Float.MIN_VALUE), 0.0F); + + failures += Tests.test("Math.round", Double.NaN, Math.round(Double.NaN), 0.0); + failures += Tests.test("Math.round", Double.POSITIVE_INFINITY, + Math.round(Double.POSITIVE_INFINITY), Long.MAX_VALUE); + failures += Tests.test("Math.round", Double.NEGATIVE_INFINITY, + Math.round(Double.NEGATIVE_INFINITY), Long.MIN_VALUE); + failures += Tests.test("Math.round", -(double)Long.MIN_VALUE, + Math.round(-(double)Long.MIN_VALUE), Long.MAX_VALUE); + failures += Tests.test("Math.round", (double) Long.MIN_VALUE, + Math.round((double) Long.MIN_VALUE), Long.MIN_VALUE); + failures += Tests.test("Math.round", 0, Math.round(0), 0.0); + failures += Tests.test("Math.round", Double.MIN_VALUE, + Math.round(Double.MIN_VALUE), 0.0); + failures += Tests.test("Math.round", -Double.MIN_VALUE, + Math.round(-Double.MIN_VALUE), 0.0); + + return failures; + } }