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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *   http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 
     18 package com.hp.creals;
     19 
     20 import junit.framework.AssertionFailedError;
     21 import junit.framework.TestCase;
     22 
     23 import java.util.Random;
     24 
     25 public class ConversionTest extends TestCase {
     26     private static void check(boolean x, String s) {
     27         if (!x) throw new AssertionFailedError(s);
     28     }
     29     final static int NRANDOM = 100;    // Number of random values to
     30                                        // test.  Bigger ==> slower
     31     final CR BIG = CR.valueOf(Double.MAX_VALUE);
     32     final CR HUGE = BIG.multiply(BIG);
     33     final CR TINY = CR.ONE.shiftRight(1078);
     34 
     35     public void checkDoubleConversion(double x) {
     36         if (!Double.isNaN(x) && !Double.isInfinite(x)) {
     37             CR crValue = CR.valueOf(x);
     38             check(x == crValue.doubleValue(), "double conversion: " + x);
     39         }
     40     }
     41 
     42     public void checkFloatConversion(float f) {
     43         if (!Float.isNaN(f) && !Float.isInfinite(f)) {
     44             CR crValue = CR.valueOf(f);
     45             check(f == crValue.floatValue(), "float conversion: " + f);
     46         }
     47     }
     48 
     49     public void checkNearbyConversions(double x) {
     50         checkDoubleConversion(x);
     51         checkDoubleConversion(Math.nextAfter(x, Double.NEGATIVE_INFINITY));
     52         checkDoubleConversion(Math.nextAfter(x, Double.POSITIVE_INFINITY));
     53         float f = (float)x;
     54         checkFloatConversion(f);
     55         checkFloatConversion(Math.nextAfter(f, Double.NEGATIVE_INFINITY));
     56         checkFloatConversion(Math.nextAfter(f, Double.POSITIVE_INFINITY));
     57     }
     58 
     59     public void testConversions() {
     60         check(TINY.doubleValue() == 0.0d, "Tiny.doubleValue()");
     61         checkNearbyConversions(0.0d);
     62         checkNearbyConversions(Double.MAX_VALUE);
     63         checkNearbyConversions(Double.MIN_VALUE);
     64         check(HUGE.doubleValue() == Double.POSITIVE_INFINITY,
     65                 "double +infinity");
     66         check(HUGE.negate().doubleValue() == Double.NEGATIVE_INFINITY,
     67                 "double -infinity");
     68         check(HUGE.floatValue() == Float.POSITIVE_INFINITY,
     69                 "float +infinity");
     70         check(HUGE.negate().floatValue() == Float.NEGATIVE_INFINITY,
     71                 "float -infinity");
     72         for (double x = 1.0d; x != 0.0d; x /= 2.0d) {
     73             checkNearbyConversions(x);
     74         }
     75         for (double x = -1.0d; x != Double.NEGATIVE_INFINITY; x *= 2.0d) {
     76             checkNearbyConversions(x);
     77         }
     78         Random r = new Random();  // Random seed!
     79         for (int i = 0; i < NRANDOM; ++i) {
     80             double d = Math.exp(1000.0 * r.nextDouble());
     81             if (r.nextBoolean()) d = -d;
     82             checkNearbyConversions(d);
     83         }
     84     }
     85 }
     86