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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.lang.Math;
24 
25 import java.math.BigInteger;
26 
27 import org.testng.annotations.Test;
28 
29 import static org.testng.Assert.assertEquals;
30 
31 // Android-removed: Private constructor, main() method, randomness tests.
32 public class MultiplicationTests {
33 
34     // Calculate high 64 bits of 128 product using BigInteger.
multiplyHighBigInt(long x, long y)35     private static long multiplyHighBigInt(long x, long y) {
36         return BigInteger.valueOf(x).multiply(BigInteger.valueOf(y))
37             .shiftRight(64).longValue();
38     }
39 
40     @Test
testMultiplyHigh()41     public void testMultiplyHigh() {
42         // check some boundary cases
43         long[][] v = new long[][]{
44             {0L, 0L},
45             {-1L, 0L},
46             {0L, -1L},
47             {1L, 0L},
48             {0L, 1L},
49             {-1L, -1L},
50             {-1L, 1L},
51             {1L, -1L},
52             {1L, 1L},
53             {Long.MAX_VALUE, Long.MAX_VALUE},
54             {Long.MAX_VALUE, -Long.MAX_VALUE},
55             {-Long.MAX_VALUE, Long.MAX_VALUE},
56             {-Long.MAX_VALUE, -Long.MAX_VALUE},
57             {Long.MAX_VALUE, Long.MIN_VALUE},
58             {Long.MIN_VALUE, Long.MAX_VALUE},
59             {Long.MIN_VALUE, Long.MIN_VALUE}
60         };
61 
62         for (long[] xy : v) {
63             long x = xy[0];
64             long y = xy[1];
65             long p1 = multiplyHighBigInt(x, y);
66             long p2 = Math.multiplyHigh(x, y);
67             assertEquals(p1, p2);
68         }
69     }
70 
71 }