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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package org.graalvm.compiler.replacements.nodes.arithmetic;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_2;

import org.graalvm.compiler.core.common.type.IntegerStamp;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
import org.graalvm.compiler.nodeinfo.InputType;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.AbstractBeginNode;
import org.graalvm.compiler.nodes.ConstantNode;
import org.graalvm.compiler.nodes.NodeView;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.calc.SubNode;
import org.graalvm.compiler.nodes.extended.AnchoringNode;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.nodes.util.GraphUtil;

import jdk.vm.ci.meta.JavaConstant;
import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.SpeculationLog.SpeculationReason;

Node representing an exact integer substraction that will throw an ArithmeticException in case the addition would overflow the 32 bit range.
/** * Node representing an exact integer substraction that will throw an {@link ArithmeticException} in * case the addition would overflow the 32 bit range. */
@NodeInfo(cycles = CYCLES_2, size = SIZE_2) public final class IntegerSubExactNode extends SubNode implements IntegerExactArithmeticNode { public static final NodeClass<IntegerSubExactNode> TYPE = NodeClass.create(IntegerSubExactNode.class); @OptionalInput(InputType.Anchor) protected AnchoringNode anchor; protected final SpeculationReason speculation; public IntegerSubExactNode(ValueNode x, ValueNode y, SpeculationReason speculation) { super(TYPE, x, y); setStamp(x.stamp(NodeView.DEFAULT).unrestricted()); assert x.stamp(NodeView.DEFAULT).isCompatible(y.stamp(NodeView.DEFAULT)) && x.stamp(NodeView.DEFAULT) instanceof IntegerStamp; this.speculation = speculation; } @Override public boolean inferStamp() { /* * Note: it is not allowed to use the foldStamp method of the regular sub node as we do not * know the result stamp of this node if we do not know whether we may deopt. If we know we * can never overflow we will replace this node with its non overflow checking counterpart * anyway. */ return false; } @Override public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) { if (GraphUtil.unproxify(forX) == GraphUtil.unproxify(forY)) { return ConstantNode.forIntegerStamp(stamp(NodeView.DEFAULT), 0); } if (forX.isConstant() && forY.isConstant()) { return canonicalXYconstant(forX, forY); } else if (forY.isConstant()) { long c = forY.asJavaConstant().asLong(); if (c == 0) { return forX; } } if (!IntegerStamp.subtractionCanOverflow((IntegerStamp) x.stamp(NodeView.DEFAULT), (IntegerStamp) y.stamp(NodeView.DEFAULT))) { return new SubNode(x, y).canonical(tool); } return this; } private ValueNode canonicalXYconstant(ValueNode forX, ValueNode forY) { JavaConstant xConst = forX.asJavaConstant(); JavaConstant yConst = forY.asJavaConstant(); assert xConst.getJavaKind() == yConst.getJavaKind(); try { if (xConst.getJavaKind() == JavaKind.Int) { return ConstantNode.forInt(Math.subtractExact(xConst.asInt(), yConst.asInt())); } else { assert xConst.getJavaKind() == JavaKind.Long; return ConstantNode.forLong(Math.subtractExact(xConst.asLong(), yConst.asLong())); } } catch (ArithmeticException ex) { // The operation will result in an overflow exception, so do not canonicalize. } return this; } @Override public IntegerExactArithmeticSplitNode createSplit(AbstractBeginNode next, AbstractBeginNode deopt) { return graph().add(new IntegerSubExactSplitNode(stamp(NodeView.DEFAULT), getX(), getY(), next, deopt)); } @Override public SpeculationReason getSpeculation() { return speculation; } @Override public AnchoringNode getAnchor() { return anchor; } @Override public void setAnchor(AnchoringNode x) { updateUsagesInterface(this.anchor, x); this.anchor = x; } @Override public void lower(LoweringTool tool) { IntegerExactArithmeticSplitNode.lower(tool, this); } }