1 /*
   2  * Copyright (c) 2014, 2015, 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.match;
  24 
  25 import static org.graalvm.compiler.debug.GraalDebugConfig.Options.LogVerbose;
  26 
  27 import java.util.List;
  28 
  29 import jdk.vm.ci.meta.Value;
  30 
  31 import org.graalvm.compiler.core.gen.NodeLIRBuilder;
  32 import org.graalvm.compiler.core.match.MatchPattern.MatchResultCode;
  33 import org.graalvm.compiler.core.match.MatchPattern.Result;
  34 import org.graalvm.compiler.debug.Debug;
  35 import org.graalvm.compiler.debug.DebugCounter;
  36 import org.graalvm.compiler.graph.GraalGraphError;
  37 import org.graalvm.compiler.graph.Node;
  38 import org.graalvm.compiler.nodeinfo.Verbosity;
  39 
  40 /**
  41  * A named {@link MatchPattern} along with a {@link MatchGenerator} that can be evaluated to replace
  42  * one or more {@link Node}s with a single {@link Value}.
  43  */
  44 
  45 public class MatchStatement {
  46     private static final DebugCounter MatchStatementSuccess = Debug.counter("MatchStatementSuccess");
  47 
  48     /**
  49      * A printable name for this statement. Usually it's just the name of the method doing the
  50      * emission.
  51      */
  52     private final String name;
  53 
  54     /**
  55      * The actual match pattern.
  56      */
  57     private final MatchPattern pattern;
  58 
  59     /**
  60      * The method in the {@link NodeLIRBuilder} subclass that will actually do the code emission.
  61      */
  62     private MatchGenerator generatorMethod;
  63 
  64     /**
  65      * The name of arguments in the order they are expected to be passed to the generator method.
  66      */
  67     private String[] arguments;
  68 
  69     public MatchStatement(String name, MatchPattern pattern, MatchGenerator generator, String[] arguments) {
  70         this.name = name;
  71         this.pattern = pattern;
  72         this.generatorMethod = generator;
  73         this.arguments = arguments;
  74     }
  75 
  76     /**
  77      * Attempt to match the current statement against a Node.
  78      *
  79      * @param builder the current builder instance.
  80      * @param node the node to be matched
  81      * @param nodes the nodes in the current block
  82      * @return true if the statement matched something and set a {@link ComplexMatchResult} to be
  83      *         evaluated by the NodeLIRBuilder.
  84      */
  85     public boolean generate(NodeLIRBuilder builder, int index, Node node, List<Node> nodes) {
  86         assert index == nodes.indexOf(node);
  87         // Check that the basic shape matches
  88         Result result = pattern.matchShape(node, this);
  89         if (result != Result.OK) {
  90             return false;
  91         }
  92         // Now ensure that the other safety constraints are matched.
  93         MatchContext context = new MatchContext(builder, this, index, node, nodes);
  94         result = pattern.matchUsage(node, context);
  95         if (result == Result.OK) {
  96             // Invoke the generator method and set the result if it's non null.
  97             ComplexMatchResult value = generatorMethod.match(builder.getNodeMatchRules(), buildArgList(context));
  98             if (value != null) {
  99                 context.setResult(value);
 100                 MatchStatementSuccess.increment();
 101                 Debug.counter("MatchStatement[%s]", getName()).increment();
 102                 return true;
 103             }
 104             // The pattern matched but some other code generation constraint disallowed code
 105             // generation for the pattern.
 106             if (LogVerbose.getValue()) {
 107                 Debug.log("while matching %s|%s %s %s returned null", context.getRoot().toString(Verbosity.Id), context.getRoot().getClass().getSimpleName(), getName(), generatorMethod.getName());
 108                 Debug.log("with nodes %s", formatMatch(node));
 109             }
 110         } else {
 111             if (LogVerbose.getValue() && result.code != MatchResultCode.WRONG_CLASS) {
 112                 Debug.log("while matching %s|%s %s %s", context.getRoot().toString(Verbosity.Id), context.getRoot().getClass().getSimpleName(), getName(), result);
 113             }
 114         }
 115         return false;
 116     }
 117 
 118     /**
 119      * @param context
 120      * @return the Nodes captured by the match rule in the order expected by the generatorMethod
 121      */
 122     private Object[] buildArgList(MatchContext context) {
 123         Object[] result = new Object[arguments.length];
 124         for (int i = 0; i < arguments.length; i++) {
 125             if ("root".equals(arguments[i])) {
 126                 result[i] = context.getRoot();
 127             } else {
 128                 result[i] = context.namedNode(arguments[i]);
 129                 if (result[i] == null) {
 130                     throw new GraalGraphError("Can't find named node %s", arguments[i]);
 131                 }
 132             }
 133         }
 134         return result;
 135     }
 136 
 137     public String formatMatch(Node root) {
 138         return pattern.formatMatch(root);
 139     }
 140 
 141     public MatchPattern getPattern() {
 142         return pattern;
 143     }
 144 
 145     public String getName() {
 146         return name;
 147     }
 148 
 149     @Override
 150     public String toString() {
 151         return pattern.toString();
 152     }
 153 }