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 * version 2 for more details (a copy is included in the LICENSE file that
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package org.graalvm.compiler.nodes.calc;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_1;

import org.graalvm.compiler.core.common.calc.CanonicalCondition;
import org.graalvm.compiler.core.common.type.ArithmeticOpTable;
import org.graalvm.compiler.core.common.type.ArithmeticOpTable.IntegerConvertOp;
import org.graalvm.compiler.core.common.type.ArithmeticOpTable.IntegerConvertOp.Narrow;
import org.graalvm.compiler.core.common.type.ArithmeticOpTable.IntegerConvertOp.ZeroExtend;
import org.graalvm.compiler.core.common.type.IntegerStamp;
import org.graalvm.compiler.core.common.type.PrimitiveStamp;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
import org.graalvm.compiler.lir.gen.ArithmeticLIRGeneratorTool;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.NodeView;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;

import jdk.vm.ci.code.CodeUtil;

The ZeroExtendNode converts an integer to a wider integer using zero extension.
/** * The {@code ZeroExtendNode} converts an integer to a wider integer using zero extension. */
@NodeInfo(cycles = CYCLES_1) public final class ZeroExtendNode extends IntegerConvertNode<ZeroExtend, Narrow> { public static final NodeClass<ZeroExtendNode> TYPE = NodeClass.create(ZeroExtendNode.class); private final boolean inputAlwaysPositive; public ZeroExtendNode(ValueNode input, int resultBits) { this(input, PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)), resultBits, false); assert 0 < PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)) && PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)) <= resultBits; } public ZeroExtendNode(ValueNode input, int inputBits, int resultBits, boolean inputAlwaysPositive) { super(TYPE, ArithmeticOpTable::getZeroExtend, ArithmeticOpTable::getNarrow, inputBits, resultBits, input); this.inputAlwaysPositive = inputAlwaysPositive; } public static ValueNode create(ValueNode input, int resultBits, NodeView view) { return create(input, PrimitiveStamp.getBits(input.stamp(view)), resultBits, view, false); } public static ValueNode create(ValueNode input, int inputBits, int resultBits, NodeView view) { return create(input, inputBits, resultBits, view, false); } public static ValueNode create(ValueNode input, int inputBits, int resultBits, NodeView view, boolean alwaysPositive) { IntegerConvertOp<ZeroExtend> signExtend = ArithmeticOpTable.forStamp(input.stamp(view)).getZeroExtend(); ValueNode synonym = findSynonym(signExtend, input, inputBits, resultBits, signExtend.foldStamp(inputBits, resultBits, input.stamp(view))); if (synonym != null) { return synonym; } return canonical(null, input, inputBits, resultBits, view, alwaysPositive); } @Override public boolean isLossless() { return true; } public boolean isInputAlwaysPositive() { return inputAlwaysPositive; } @Override public boolean preservesOrder(CanonicalCondition cond) { switch (cond) { case LT: return false; default: return true; } } @Override public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) { NodeView view = NodeView.from(tool); ValueNode ret = super.canonical(tool, forValue); if (ret != this) { return ret; } return canonical(this, forValue, getInputBits(), getResultBits(), view, inputAlwaysPositive); } private static ValueNode canonical(ZeroExtendNode zeroExtendNode, ValueNode forValue, int inputBits, int resultBits, NodeView view, boolean alwaysPositive) { ZeroExtendNode self = zeroExtendNode; if (forValue instanceof ZeroExtendNode) { // xxxx -(zero-extend)-> 0000 xxxx -(zero-extend)-> 00000000 0000xxxx // ==> xxxx -(zero-extend)-> 00000000 0000xxxx ZeroExtendNode other = (ZeroExtendNode) forValue; return new ZeroExtendNode(other.getValue(), other.getInputBits(), resultBits, other.isInputAlwaysPositive()); } if (forValue instanceof NarrowNode) { NarrowNode narrow = (NarrowNode) forValue; Stamp inputStamp = narrow.getValue().stamp(view); if (inputStamp instanceof IntegerStamp) { IntegerStamp istamp = (IntegerStamp) inputStamp; long mask = CodeUtil.mask(PrimitiveStamp.getBits(narrow.stamp(view))); if ((istamp.upMask() & ~mask) == 0) { // The original value cannot change because of the narrow and zero extend. if (istamp.getBits() < resultBits) { // Need to keep the zero extend, skip the narrow. return create(narrow.getValue(), resultBits, view); } else if (istamp.getBits() > resultBits) { // Need to keep the narrow, skip the zero extend. return NarrowNode.create(narrow.getValue(), resultBits, view); } else { assert istamp.getBits() == resultBits; // Just return the original value. return narrow.getValue(); } } } } if (self == null) { self = new ZeroExtendNode(forValue, inputBits, resultBits, alwaysPositive); } return self; } @Override public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) { nodeValueMap.setResult(this, gen.emitZeroExtend(nodeValueMap.operand(getValue()), getInputBits(), getResultBits())); } @Override public boolean mayNullCheckSkipConversion() { return true; } }