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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * 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).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package org.graalvm.compiler.nodes.memory;

import static org.graalvm.compiler.nodeinfo.InputType.Memory;
import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;

import org.graalvm.compiler.core.common.LIRKind;
import org.graalvm.compiler.core.common.type.ObjectStamp;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.debug.DebugCloseable;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.graph.spi.Canonicalizable;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.NodeView;
import org.graalvm.compiler.nodes.ValueNodeUtil;
import org.graalvm.compiler.nodes.ValuePhiNode;
import org.graalvm.compiler.nodes.extended.GuardingNode;
import org.graalvm.compiler.nodes.memory.address.AddressNode;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
import jdk.internal.vm.compiler.word.LocationIdentity;

A floating read of a value from memory specified in terms of an object base and an object relative location. This node does not null check the object.
/** * A floating read of a value from memory specified in terms of an object base and an object * relative location. This node does not null check the object. */
@NodeInfo(nameTemplate = "Read#{p#location/s}", cycles = CYCLES_2, size = SIZE_1) public final class FloatingReadNode extends FloatingAccessNode implements LIRLowerableAccess, Canonicalizable { public static final NodeClass<FloatingReadNode> TYPE = NodeClass.create(FloatingReadNode.class); @OptionalInput(Memory) MemoryNode lastLocationAccess; public FloatingReadNode(AddressNode address, LocationIdentity location, MemoryNode lastLocationAccess, Stamp stamp) { this(address, location, lastLocationAccess, stamp, null, BarrierType.NONE); } public FloatingReadNode(AddressNode address, LocationIdentity location, MemoryNode lastLocationAccess, Stamp stamp, GuardingNode guard) { this(address, location, lastLocationAccess, stamp, guard, BarrierType.NONE); } public FloatingReadNode(AddressNode address, LocationIdentity location, MemoryNode lastLocationAccess, Stamp stamp, GuardingNode guard, BarrierType barrierType) { super(TYPE, address, location, stamp, guard, barrierType); this.lastLocationAccess = lastLocationAccess; // The input to floating reads must be always non-null or have at least a guard. assert guard != null || !(address.getBase().stamp(NodeView.DEFAULT) instanceof ObjectStamp) || address.getBase() instanceof ValuePhiNode || ((ObjectStamp) address.getBase().stamp(NodeView.DEFAULT)).nonNull() : address.getBase(); } @Override public MemoryNode getLastLocationAccess() { return lastLocationAccess; } @Override public void setLastLocationAccess(MemoryNode newlla) { updateUsages(ValueNodeUtil.asNode(lastLocationAccess), ValueNodeUtil.asNode(newlla)); lastLocationAccess = newlla; } @Override public void generate(NodeLIRBuilderTool gen) { LIRKind readKind = gen.getLIRGeneratorTool().getLIRKind(stamp(NodeView.DEFAULT)); gen.setResult(this, gen.getLIRGeneratorTool().getArithmetic().emitLoad(readKind, gen.operand(address), null)); } @Override public Node canonical(CanonicalizerTool tool) { Node result = ReadNode.canonicalizeRead(this, getAddress(), getLocationIdentity(), tool); if (result != this) { return result; } if (tool.canonicalizeReads() && getAddress().hasMoreThanOneUsage() && lastLocationAccess instanceof WriteNode) { WriteNode write = (WriteNode) lastLocationAccess; if (write.getAddress() == getAddress() && write.getAccessStamp().isCompatible(getAccessStamp())) { // Same memory location with no intervening write return write.value(); } } return this; } @SuppressWarnings("try") @Override public FixedAccessNode asFixedNode() { try (DebugCloseable position = withNodeSourcePosition()) { ReadNode result = graph().add(new ReadNode(getAddress(), getLocationIdentity(), stamp(NodeView.DEFAULT), getBarrierType())); result.setGuard(getGuard()); return result; } } @Override public boolean verify() { MemoryNode lla = getLastLocationAccess(); assert lla != null || getLocationIdentity().isImmutable() : "lastLocationAccess of " + this + " shouldn't be null for mutable location identity " + getLocationIdentity(); return super.verify(); } @Override public Stamp getAccessStamp() { return stamp(NodeView.DEFAULT); } }