1 /* 2 * Copyright (c) 2009, 2018, 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 24 25 package org.graalvm.compiler.nodes.java; 26 27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2; 28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1; 29 30 import org.graalvm.compiler.core.common.type.StampFactory; 31 import org.graalvm.compiler.graph.NodeClass; 32 import org.graalvm.compiler.graph.spi.Canonicalizable; 33 import org.graalvm.compiler.graph.spi.CanonicalizerTool; 34 import org.graalvm.compiler.nodeinfo.NodeInfo; 35 import org.graalvm.compiler.nodes.ConstantNode; 36 import org.graalvm.compiler.nodes.FixedWithNextNode; 37 import org.graalvm.compiler.nodes.ValueNode; 38 import org.graalvm.compiler.nodes.spi.ArrayLengthProvider; 39 import org.graalvm.compiler.nodes.spi.Lowerable; 40 import org.graalvm.compiler.nodes.spi.LoweringTool; 41 import org.graalvm.compiler.nodes.spi.Virtualizable; 42 import org.graalvm.compiler.nodes.spi.VirtualizerTool; 43 import org.graalvm.compiler.nodes.util.GraphUtil; 44 import org.graalvm.compiler.nodes.virtual.VirtualArrayNode; 45 46 import jdk.vm.ci.meta.ConstantReflectionProvider; 47 48 /** 49 * The {@code ArrayLength} instruction gets the length of an array. 50 */ 51 @NodeInfo(cycles = CYCLES_2, size = SIZE_1) 52 public final class ArrayLengthNode extends FixedWithNextNode implements Canonicalizable.Unary<ValueNode>, Lowerable, Virtualizable { 53 54 public static final NodeClass<ArrayLengthNode> TYPE = NodeClass.create(ArrayLengthNode.class); 55 @Input ValueNode array; 56 57 public ValueNode array() { 58 return array; 59 } 60 61 @Override 62 public ValueNode getValue() { 63 return array; 64 } 65 66 public ArrayLengthNode(ValueNode array) { 67 super(TYPE, StampFactory.positiveInt()); 68 this.array = array; 69 } 70 71 public static ValueNode create(ValueNode forValue, ConstantReflectionProvider constantReflection) { 72 if (forValue instanceof NewArrayNode) { 73 NewArrayNode newArray = (NewArrayNode) forValue; 74 return newArray.length(); 75 } 76 77 ValueNode length = readArrayLength(forValue, constantReflection); 78 if (length != null) { 79 return length; 80 } 81 return new ArrayLengthNode(forValue); 82 } 83 84 @Override 85 public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) { 86 ValueNode length = readArrayLength(forValue, tool.getConstantReflection()); 87 if (length != null) { 88 return length; 89 } 90 return this; 91 } 92 93 /** 94 * Gets the length of an array if possible. 95 * 96 * @return a node representing the length of {@code array} or null if it is not available 97 */ 98 public static ValueNode readArrayLength(ValueNode originalArray, ConstantReflectionProvider constantReflection) { 99 return GraphUtil.arrayLength(originalArray, ArrayLengthProvider.FindLengthMode.CANONICALIZE_READ, constantReflection); 100 } 101 102 @Override 103 public void lower(LoweringTool tool) { 104 tool.getLowerer().lower(this, tool); 105 } 106 107 @NodeIntrinsic 108 public static native int arrayLength(Object array); 109 110 @Override 111 public void virtualize(VirtualizerTool tool) { 112 ValueNode alias = tool.getAlias(array()); 113 if (alias instanceof VirtualArrayNode) { 114 VirtualArrayNode virtualArray = (VirtualArrayNode) alias; 115 tool.replaceWithValue(ConstantNode.forInt(virtualArray.entryCount(), graph())); 116 } 117 } 118 }