1 /* 2 * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.openjdk.bench.vm.compiler; 24 25 import org.openjdk.jmh.annotations.Benchmark; 26 import org.openjdk.jmh.annotations.BenchmarkMode; 27 import org.openjdk.jmh.annotations.Mode; 28 import org.openjdk.jmh.annotations.OutputTimeUnit; 29 import org.openjdk.jmh.annotations.Param; 30 import org.openjdk.jmh.annotations.Scope; 31 import org.openjdk.jmh.annotations.Setup; 32 import org.openjdk.jmh.annotations.State; 33 34 import java.util.concurrent.TimeUnit; 35 36 /** 37 * Tests speed of multiplication calculations with constants. 38 */ 39 @BenchmarkMode(Mode.AverageTime) 40 @OutputTimeUnit(TimeUnit.NANOSECONDS) 41 @State(Scope.Thread) 42 public class Multiplication { 43 44 @Param("500") 45 private int arraySize; 46 47 private long[] longArraySmall, longArrayBig; 48 49 @Setup 50 public void setupSubclass() { 51 longArraySmall = new long[arraySize]; 52 longArrayBig = new long[arraySize]; 53 54 /* 55 * small values always have higher 32 bits cleared. big values always 56 * have higher 32 bits set. 57 */ 58 for (int i = 0; i < arraySize; i++) { 59 longArraySmall[i] = 100L * i + i; 60 longArrayBig[i] = ((100L * i + i) << 32) + 4543 + i * 4; 61 } 62 } 63 64 /* helper for small constant benchmarks. */ 65 private static long smallConstantHelper(long[] values) { 66 long sum = 0; 67 for (long value : values) { 68 sum += value * 453543L; 69 } 70 return sum; 71 } 72 73 /* helper for big constant benchmarks. */ 74 private static long bigConstantHelper(long[] values) { 75 long sum = 0; 76 for (long value : values) { 77 sum += value * 4554345533543L; 78 } 79 return sum; 80 } 81 82 /** 83 * Test multiplications of longs. One of the operands is a small constant and the other is a variable that always is 84 * small. 85 */ 86 @Benchmark 87 public long testLongSmallVariableSmallConstantMul() { 88 return smallConstantHelper(longArraySmall); 89 } 90 91 /** 92 * Test multiplications of longs. One of the operands is a big constant and the other is a variable that always is 93 * small. 94 */ 95 @Benchmark 96 public long testLongSmallVariableBigConstantMul() { 97 return bigConstantHelper(longArraySmall); 98 } 99 100 /** 101 * Test multiplications of longs. One of the operands is a small constant and the other is a variable that always is 102 * big. 103 */ 104 @Benchmark 105 public long testLongBigVariableSmallConstantMul() { 106 return smallConstantHelper(longArrayBig); 107 } 108 109 /** 110 * Test multiplications of longs. One of the operands is a big constant and the other is a variable that always is 111 * big. 112 */ 113 @Benchmark 114 public long testLongBigVariableBigConstantMul() { 115 return bigConstantHelper(longArrayBig); 116 } 117 118 }