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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package org.openjdk.bench.vm.compiler; 26 27 import org.openjdk.jmh.annotations.Benchmark; 28 import org.openjdk.jmh.annotations.BenchmarkMode; 29 import org.openjdk.jmh.annotations.Mode; 30 import org.openjdk.jmh.annotations.OutputTimeUnit; 31 import org.openjdk.jmh.annotations.Param; 32 import org.openjdk.jmh.annotations.Scope; 33 import org.openjdk.jmh.annotations.Setup; 34 import org.openjdk.jmh.annotations.State; 35 36 import java.util.concurrent.TimeUnit; 37 38 /** 39 * Tests speed of multiplication calculations with constants. 40 */ 41 @BenchmarkMode(Mode.AverageTime) 42 @OutputTimeUnit(TimeUnit.NANOSECONDS) 43 @State(Scope.Thread) 44 public class Multiplication { 45 46 @Param("500") 47 private int arraySize; 48 49 private long[] longArraySmall, longArrayBig; 50 51 @Setup 52 public void setupSubclass() { 53 longArraySmall = new long[arraySize]; 54 longArrayBig = new long[arraySize]; 55 56 /* 57 * small values always have higher 32 bits cleared. big values always 58 * have higher 32 bits set. 59 */ 60 for (int i = 0; i < arraySize; i++) { 61 longArraySmall[i] = 100L * i + i; 62 longArrayBig[i] = ((100L * i + i) << 32) + 4543 + i * 4; 63 } 64 } 65 66 /* helper for small constant benchmarks. */ 67 private static long smallConstantHelper(long[] values) { 68 long sum = 0; 69 for (long value : values) { 70 sum += value * 453543L; 71 } 72 return sum; 73 } 74 75 /* helper for big constant benchmarks. */ 76 private static long bigConstantHelper(long[] values) { 77 long sum = 0; 78 for (long value : values) { 79 sum += value * 4554345533543L; 80 } 81 return sum; 82 } 83 84 /** 85 * Test multiplications of longs. One of the operands is a small constant and the other is a variable that always is 86 * small. 87 */ 88 @Benchmark 89 public long testLongSmallVariableSmallConstantMul() { 90 return smallConstantHelper(longArraySmall); 91 } 92 93 /** 94 * Test multiplications of longs. One of the operands is a big constant and the other is a variable that always is 95 * small. 96 */ 97 @Benchmark 98 public long testLongSmallVariableBigConstantMul() { 99 return bigConstantHelper(longArraySmall); 100 } 101 102 /** 103 * Test multiplications of longs. One of the operands is a small constant and the other is a variable that always is 104 * big. 105 */ 106 @Benchmark 107 public long testLongBigVariableSmallConstantMul() { 108 return smallConstantHelper(longArrayBig); 109 } 110 111 /** 112 * Test multiplications of longs. One of the operands is a big constant and the other is a variable that always is 113 * big. 114 */ 115 @Benchmark 116 public long testLongBigVariableBigConstantMul() { 117 return bigConstantHelper(longArrayBig); 118 } 119 120 }