1 /*
   2  * Copyright (c) 2011, 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.graalvm.compiler.core.test;
  24 
  25 import org.junit.Test;
  26 
  27 import org.graalvm.compiler.debug.Debug;
  28 import org.graalvm.compiler.debug.Debug.Scope;
  29 import org.graalvm.compiler.debug.DebugDumpScope;
  30 import org.graalvm.compiler.loop.DefaultLoopPolicies;
  31 import org.graalvm.compiler.loop.phases.LoopUnswitchingPhase;
  32 import org.graalvm.compiler.nodes.StructuredGraph;
  33 import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
  34 import org.graalvm.compiler.phases.common.CanonicalizerPhase;
  35 import org.graalvm.compiler.phases.tiers.PhaseContext;
  36 
  37 public class LoopUnswitchTest extends GraalCompilerTest {
  38 
  39     public static int referenceSnippet1(int a) {
  40         int sum = 0;
  41         if (a > 2) {
  42             for (int i = 0; i < 1000; i++) {
  43                 sum += 2;
  44             }
  45         } else {
  46             for (int i = 0; i < 1000; i++) {
  47                 sum += a;
  48             }
  49         }
  50         return sum;
  51     }
  52 
  53     public static int test1Snippet(int a) {
  54         int sum = 0;
  55         for (int i = 0; i < 1000; i++) {
  56             if (a > 2) {
  57                 sum += 2;
  58             } else {
  59                 sum += a;
  60             }
  61         }
  62         return sum;
  63     }
  64 
  65     public static int referenceSnippet2(int a) {
  66         int sum = 0;
  67         switch (a) {
  68             case 0:
  69                 for (int i = 0; i < 1000; i++) {
  70                     sum += System.currentTimeMillis();
  71                 }
  72                 break;
  73             case 1:
  74                 for (int i = 0; i < 1000; i++) {
  75                     sum += 1;
  76                     sum += 5;
  77                 }
  78                 break;
  79             case 55:
  80                 for (int i = 0; i < 1000; i++) {
  81                     sum += 5;
  82                 }
  83                 break;
  84             default:
  85                 for (int i = 0; i < 1000; i++) {
  86                     // nothing
  87                 }
  88                 break;
  89         }
  90         return sum;
  91     }
  92 
  93     @SuppressWarnings("fallthrough")
  94     public static int test2Snippet(int a) {
  95         int sum = 0;
  96         for (int i = 0; i < 1000; i++) {
  97             switch (a) {
  98                 case 0:
  99                     sum += System.currentTimeMillis();
 100                     break;
 101                 case 1:
 102                     sum += 1;
 103                     // fall through
 104                 case 55:
 105                     sum += 5;
 106                     break;
 107                 default:
 108                     // nothing
 109                     break;
 110             }
 111         }
 112         return sum;
 113     }
 114 
 115     @Test
 116     public void test1() {
 117         test("test1Snippet", "referenceSnippet1");
 118     }
 119 
 120     @Test
 121     public void test2() {
 122         test("test2Snippet", "referenceSnippet2");
 123     }
 124 
 125     @SuppressWarnings("try")
 126     private void test(String snippet, String referenceSnippet) {
 127         final StructuredGraph graph = parseEager(snippet, AllowAssumptions.NO);
 128         final StructuredGraph referenceGraph = parseEager(referenceSnippet, AllowAssumptions.NO);
 129 
 130         new LoopUnswitchingPhase(new DefaultLoopPolicies()).apply(graph);
 131 
 132         // Framestates create comparison problems
 133         graph.clearAllStateAfter();
 134         referenceGraph.clearAllStateAfter();
 135 
 136         new CanonicalizerPhase().apply(graph, new PhaseContext(getProviders()));
 137         new CanonicalizerPhase().apply(referenceGraph, new PhaseContext(getProviders()));
 138         try (Scope s = Debug.scope("Test", new DebugDumpScope("Test:" + snippet))) {
 139             assertEquals(referenceGraph, graph);
 140         } catch (Throwable e) {
 141             throw Debug.handle(e);
 142         }
 143     }
 144 }