1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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13  * accompanied this code).
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23 package test.java.math.BigInteger;
24 
25 import static java.math.BigInteger.ONE;
26 
27 import java.math.BigInteger;
28 import java.util.ArrayList;
29 import java.util.Arrays;
30 import java.util.Collections;
31 import java.util.List;
32 import java.util.Random;
33 
34 import org.testng.Assert;
35 import org.testng.annotations.Test;
36 
37 /**
38  * @test
39  * @bug 7131192
40  * @summary This test ensures that BigInteger.floatValue() and
41  *          BigInteger.doubleValue() behave correctly.
42  * @author Louis Wasserman
43  */
44 
45 // Android-changed: Replace error printing with asserts.
46 public class PrimitiveConversionTests {
47     static final List<BigInteger> ALL_BIGINTEGER_CANDIDATES;
48 
49     static {
50         List<BigInteger> samples = new ArrayList<>();
51         // Now add values near 2^N for lots of values of N.
52         for (int exponent : Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 31, 32, 33,
53                 34, 62, 63, 64, 65, 71, 72, 73, 79, 80, 81, 255, 256, 257, 511,
54                 512, 513, Double.MAX_EXPONENT - 1, Double.MAX_EXPONENT,
55                 Double.MAX_EXPONENT + 1, 2000, 2001, 2002)) {
56             BigInteger x = ONE.shiftLeft(exponent);
57             for (BigInteger y : Arrays.asList(x, x.add(ONE), x.subtract(ONE))) {
58                 samples.add(y);
y.negate()59                 samples.add(y.negate());
60             }
61         }
62 
63         Random rng = new Random(1234567);
64         for (int i = 0; i < 2000; i++) {
samples.add(new BigInteger(rng.nextInt(2000), rng))65             samples.add(new BigInteger(rng.nextInt(2000), rng));
66         }
67 
68         ALL_BIGINTEGER_CANDIDATES = Collections.unmodifiableList(samples);
69     }
70 
71     @Test
testDoubleValue()72     public void testDoubleValue() {
73         for (BigInteger big : ALL_BIGINTEGER_CANDIDATES) {
74             double expected = Double.parseDouble(big.toString());
75             double actual = big.doubleValue();
76 
77             // should be bitwise identical
78             Assert.assertEquals(Double.doubleToRawLongBits(actual),
79                     Double.doubleToRawLongBits(expected));
80         }
81     }
82 
83     @Test
testFloatValue()84     public void testFloatValue() {
85         for (BigInteger big : ALL_BIGINTEGER_CANDIDATES) {
86             float expected = Float.parseFloat(big.toString());
87             float actual = big.floatValue();
88 
89             // should be bitwise identical
90             Assert.assertEquals(Float.floatToRawIntBits(actual),
91                     Float.floatToRawIntBits(expected));
92         }
93     }
94 
95 }
96