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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 jdk.vm.ci.code.CodeUtil;
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.SignExtend;
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;

The SignExtendNode converts an integer to a wider integer using sign extension.
/** * The {@code SignExtendNode} converts an integer to a wider integer using sign extension. */
@NodeInfo(cycles = CYCLES_1) public final class SignExtendNode extends IntegerConvertNode<SignExtend, Narrow> { public static final NodeClass<SignExtendNode> TYPE = NodeClass.create(SignExtendNode.class); public SignExtendNode(ValueNode input, int resultBits) { this(input, PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)), resultBits); assert 0 < PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)) && PrimitiveStamp.getBits(input.stamp(NodeView.DEFAULT)) <= resultBits; } public SignExtendNode(ValueNode input, int inputBits, int resultBits) { super(TYPE, ArithmeticOpTable::getSignExtend, ArithmeticOpTable::getNarrow, inputBits, resultBits, input); } public static ValueNode create(ValueNode input, int resultBits, NodeView view) { return create(input, PrimitiveStamp.getBits(input.stamp(view)), resultBits, view); } public static ValueNode create(ValueNode input, int inputBits, int resultBits, NodeView view) { IntegerConvertOp<SignExtend> signExtend = ArithmeticOpTable.forStamp(input.stamp(view)).getSignExtend(); 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); } @Override public boolean isLossless() { 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); } private static ValueNode canonical(SignExtendNode self, ValueNode forValue, int inputBits, int resultBits, NodeView view) { if (forValue instanceof SignExtendNode) { // sxxx -(sign-extend)-> ssss sxxx -(sign-extend)-> ssssssss sssssxxx // ==> sxxx -(sign-extend)-> ssssssss sssssxxx SignExtendNode other = (SignExtendNode) forValue; return SignExtendNode.create(other.getValue(), other.getInputBits(), resultBits, view); } else if (forValue instanceof ZeroExtendNode) { ZeroExtendNode other = (ZeroExtendNode) forValue; if (other.getResultBits() > other.getInputBits()) { // sxxx -(zero-extend)-> 0000 sxxx -(sign-extend)-> 00000000 0000sxxx // ==> sxxx -(zero-extend)-> 00000000 0000sxxx return ZeroExtendNode.create(other.getValue(), other.getInputBits(), resultBits, view, other.isInputAlwaysPositive()); } } if (forValue.stamp(view) instanceof IntegerStamp) { IntegerStamp inputStamp = (IntegerStamp) forValue.stamp(view); if ((inputStamp.upMask() & (1L << (inputBits - 1))) == 0L) { // 0xxx -(sign-extend)-> 0000 0xxx // ==> 0xxx -(zero-extend)-> 0000 0xxx return ZeroExtendNode.create(forValue, inputBits, resultBits, view, true); } } 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)) - 1); if (~mask <= istamp.lowerBound() && istamp.upperBound() <= mask) { // The original value cannot change because of the narrow and sign extend. if (istamp.getBits() < resultBits) { // Need to keep the sign extend, skip the narrow. return create(narrow.getValue(), resultBits, view); } else if (istamp.getBits() > resultBits) { // Need to keep the narrow, skip the sign extend. return NarrowNode.create(narrow.getValue(), resultBits, view); } else { assert istamp.getBits() == resultBits; // Just return the original value. return narrow.getValue(); } } } } return self != null ? self : new SignExtendNode(forValue, inputBits, resultBits); } @Override public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) { nodeValueMap.setResult(this, gen.emitSignExtend(nodeValueMap.operand(getValue()), getInputBits(), getResultBits())); } @Override public boolean mayNullCheckSkipConversion() { return true; } }