1 /* 2 * Copyright (c) 2014, 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.calc; 26 27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_1; 28 29 import org.graalvm.compiler.core.common.calc.CanonicalCondition; 30 import org.graalvm.compiler.core.common.type.ArithmeticOpTable; 31 import org.graalvm.compiler.core.common.type.ArithmeticOpTable.IntegerConvertOp; 32 import org.graalvm.compiler.core.common.type.ArithmeticOpTable.IntegerConvertOp.Narrow; 33 import org.graalvm.compiler.core.common.type.ArithmeticOpTable.IntegerConvertOp.ZeroExtend; 34 import org.graalvm.compiler.core.common.type.IntegerStamp; 35 import org.graalvm.compiler.core.common.type.PrimitiveStamp; 36 import org.graalvm.compiler.core.common.type.Stamp; 37 import org.graalvm.compiler.graph.NodeClass; 38 import org.graalvm.compiler.graph.spi.CanonicalizerTool; 39 import org.graalvm.compiler.lir.gen.ArithmeticLIRGeneratorTool; 40 import org.graalvm.compiler.nodeinfo.NodeInfo; 41 import org.graalvm.compiler.nodes.NodeView; 42 import org.graalvm.compiler.nodes.ValueNode; 43 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool; 44 45 import jdk.vm.ci.code.CodeUtil; 46 47 /** 48 * The {@code ZeroExtendNode} converts an integer to a wider integer using zero extension. 49 */ 50 @NodeInfo(cycles = CYCLES_1) 51 public final class ZeroExtendNode extends IntegerConvertNode<ZeroExtend, Narrow> { 52 53 public static final NodeClass<ZeroExtendNode> TYPE = NodeClass.create(ZeroExtendNode.class); 54 55 private final boolean inputAlwaysPositive; 56 ZeroExtendNode(ValueNode input, int resultBits)57 public ZeroExtendNode(ValueNode input, int resultBits) { 58 this(input, PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)), resultBits, false); 59 assert 0 < PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)) && PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)) <= resultBits; 60 } 61 62 public ZeroExtendNode(ValueNode input, int inputBits, int resultBits, boolean inputAlwaysPositive) { 63 super(TYPE, ArithmeticOpTable::getZeroExtend, ArithmeticOpTable::getNarrow, inputBits, resultBits, input); 64 this.inputAlwaysPositive = inputAlwaysPositive; 65 } 66 67 public static ValueNode create(ValueNode input, int resultBits, NodeView view) { 68 return create(input, PrimitiveStamp.getBits(input.stamp(view)), resultBits, view, false); 69 } 70 71 public static ValueNode create(ValueNode input, int inputBits, int resultBits, NodeView view) { 72 return create(input, inputBits, resultBits, view, false); 73 } 74 75 public static ValueNode create(ValueNode input, int inputBits, int resultBits, NodeView view, boolean alwaysPositive) { 76 IntegerConvertOp<ZeroExtend> signExtend = ArithmeticOpTable.forStamp(input.stamp(view)).getZeroExtend(); 77 ValueNode synonym = findSynonym(signExtend, input, inputBits, resultBits, signExtend.foldStamp(inputBits, resultBits, input.stamp(view))); 78 if (synonym != null) { 79 return synonym; 80 } 81 return canonical(null, input, inputBits, resultBits, view, alwaysPositive); 82 } 83 84 @Override 85 public boolean isLossless() { 86 return true; 87 } 88 89 public boolean isInputAlwaysPositive() { 90 return inputAlwaysPositive; 91 } 92 93 @Override 94 public boolean preservesOrder(CanonicalCondition cond) { 95 switch (cond) { 96 case LT: 97 return false; 98 default: 99 return true; 100 } 101 } 102 103 @Override 104 public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) { 105 NodeView view = NodeView.from(tool); 106 ValueNode ret = super.canonical(tool, forValue); 107 if (ret != this) { 108 return ret; 109 } 110 111 return canonical(this, forValue, getInputBits(), getResultBits(), view, inputAlwaysPositive); 112 } 113 114 private static ValueNode canonical(ZeroExtendNode zeroExtendNode, ValueNode forValue, int inputBits, int resultBits, NodeView view, boolean alwaysPositive) { 115 ZeroExtendNode self = zeroExtendNode; 116 if (forValue instanceof ZeroExtendNode) { 117 // xxxx -(zero-extend)-> 0000 xxxx -(zero-extend)-> 00000000 0000xxxx 118 // ==> xxxx -(zero-extend)-> 00000000 0000xxxx 119 ZeroExtendNode other = (ZeroExtendNode) forValue; 120 return new ZeroExtendNode(other.getValue(), other.getInputBits(), resultBits, other.isInputAlwaysPositive()); 121 } 122 if (forValue instanceof NarrowNode) { 123 NarrowNode narrow = (NarrowNode) forValue; 124 Stamp inputStamp = narrow.getValue().stamp(view); 125 if (inputStamp instanceof IntegerStamp) { 126 IntegerStamp istamp = (IntegerStamp) inputStamp; 127 long mask = CodeUtil.mask(PrimitiveStamp.getBits(narrow.stamp(view))); 128 129 if ((istamp.upMask() & ~mask) == 0) { 130 // The original value cannot change because of the narrow and zero extend. 131 132 if (istamp.getBits() < resultBits) { 133 // Need to keep the zero extend, skip the narrow. 134 return create(narrow.getValue(), resultBits, view); 135 } else if (istamp.getBits() > resultBits) { 136 // Need to keep the narrow, skip the zero extend. 137 return NarrowNode.create(narrow.getValue(), resultBits, view); 138 } else { 139 assert istamp.getBits() == resultBits; 140 // Just return the original value. 141 return narrow.getValue(); 142 } 143 } 144 } 145 } 146 147 if (self == null) { 148 self = new ZeroExtendNode(forValue, inputBits, resultBits, alwaysPositive); 149 } 150 return self; 151 } 152 153 @Override 154 public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) { 155 nodeValueMap.setResult(this, gen.emitZeroExtend(nodeValueMap.operand(getValue()), getInputBits(), getResultBits())); 156 } 157 158 @Override 159 public boolean mayNullCheckSkipConversion() { 160 return true; 161 } 162 } 163