1 /*
   2  * Copyright (c) 2009, 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.replacements.nodes;
  24 
  25 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
  26 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;
  27 
  28 import org.graalvm.compiler.api.replacements.Snippet.VarargsParameter;
  29 import org.graalvm.compiler.core.common.type.Stamp;
  30 import org.graalvm.compiler.graph.Node;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.graph.NodeInputList;
  33 import org.graalvm.compiler.graph.spi.Canonicalizable;
  34 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  35 import org.graalvm.compiler.nodeinfo.NodeInfo;
  36 import org.graalvm.compiler.nodes.FixedWithNextNode;
  37 import org.graalvm.compiler.nodes.ParameterNode;
  38 import org.graalvm.compiler.nodes.ValueNode;
  39 
  40 /**
  41  * Implements the semantics of {@link VarargsParameter}.
  42  */
  43 @NodeInfo(cycles = CYCLES_0, size = SIZE_0)
  44 public final class LoadSnippetVarargParameterNode extends FixedWithNextNode implements Canonicalizable {
  45 
  46     public static final NodeClass<LoadSnippetVarargParameterNode> TYPE = NodeClass.create(LoadSnippetVarargParameterNode.class);
  47     @Input ValueNode index;
  48 
  49     @Input NodeInputList<ParameterNode> parameters;
  50 
  51     public LoadSnippetVarargParameterNode(ParameterNode[] locals, ValueNode index, Stamp stamp) {
  52         super(TYPE, stamp);
  53         this.index = index;
  54         this.parameters = new NodeInputList<>(this, locals);
  55     }
  56 
  57     @Override
  58     public Node canonical(CanonicalizerTool tool) {
  59         if (index.isConstant()) {
  60             int indexValue = index.asJavaConstant().asInt();
  61             if (indexValue < parameters.size()) {
  62                 return parameters.get(indexValue);
  63             }
  64         }
  65         return this;
  66     }
  67 }