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.java.lang;
  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 import org.openjdk.jmh.annotations.Threads;
  34 import org.openjdk.jmh.infra.Blackhole;
  35 
  36 import java.util.concurrent.TimeUnit;
  37 
  38 @BenchmarkMode(Mode.AverageTime)
  39 @OutputTimeUnit(TimeUnit.MICROSECONDS)
  40 @State(Scope.Thread)
  41 public class Longs {
  42 
  43     @Param("500")
  44     private int size;
  45 
  46     private long[] longArraySmall;
  47     private long[] longArrayBig;
  48 
  49     @Setup
  50     public void setup() {
  51         longArraySmall = new long[size];
  52         longArrayBig = new long[size];
  53         for (int i = 0; i < size; i++) {
  54             longArraySmall[i] = 100L * i + i + 103L;
  55             longArrayBig[i] = ((100L * i + i) << 32) + 4543 + i * 4;
  56         }
  57     }
  58 
  59     /** Performs toString on a bunch of java.lang.Long:s, all with small values, just a couple of digits. */
  60     @Benchmark
  61     @Threads(Threads.MAX)
  62     public void toStringSmall(Blackhole bh) {
  63         for (long value : longArraySmall) {
  64             bh.consume(Long.toString(value));
  65         }
  66     }
  67 
  68     /** Performs toString on a bunch of java.lang.Long:s, all with large values, around 10 digits. */
  69     @Benchmark
  70     @Threads(Threads.MAX)
  71     public void toStringBig(Blackhole bh) {
  72         for (long value : longArrayBig) {
  73             bh.consume(Long.toString(value));
  74         }
  75     }
  76 
  77     /*
  78      * Have them public to avoid total unrolling
  79      */
  80     public int innerLoops = 1500;
  81 
  82     @Benchmark
  83     @Threads(Threads.MAX)
  84     public long repetitiveSubtraction() {
  85         long x = 127, dx = 0;
  86 
  87         for (int i = 0; i < innerLoops; i++) {
  88             x -= dx;
  89             dx = (dx - x);
  90         }
  91         return x;
  92     }
  93 }