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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.
 *
 * 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.LocationIdentity;
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.PiNode;
import org.graalvm.compiler.nodes.ValueNodeUtil;
import org.graalvm.compiler.nodes.extended.GuardingNode;
import org.graalvm.compiler.nodes.memory.address.AddressNode;
import org.graalvm.compiler.nodes.memory.address.OffsetAddressNode;
import org.graalvm.compiler.nodes.spi.LIRLowerable;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;

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 LIRLowerable, 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; } @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()); gen.setResult(this, gen.getLIRGeneratorTool().getArithmetic().emitLoad(readKind, gen.operand(address), null)); } @Override public Node canonical(CanonicalizerTool tool) { if (getAddress() instanceof OffsetAddressNode) { OffsetAddressNode objAddress = (OffsetAddressNode) getAddress(); if (objAddress.getBase() instanceof PiNode) { PiNode piBase = (PiNode) objAddress.getBase(); /* * If the Pi and the read have the same guard or the read is unguarded, use the * guard of the Pi along with the original value. This encourages a canonical form * guarded reads. */ if (piBase.getGuard() == getGuard() || getGuard() == null) { OffsetAddressNode newAddress = new OffsetAddressNode(piBase.getOriginalNode(), objAddress.getOffset()); return new FloatingReadNode(newAddress, getLocationIdentity(), getLastLocationAccess(), stamp(), getGuard() == null ? piBase.getGuard() : getGuard(), getBarrierType()); } } } return ReadNode.canonicalizeRead(this, getAddress(), getLocationIdentity(), tool); } @SuppressWarnings("try") @Override public FixedAccessNode asFixedNode() { try (DebugCloseable position = withNodeSourcePosition()) { return graph().add(new ReadNode(getAddress(), getLocationIdentity(), stamp(), getGuard(), getBarrierType())); } } @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(); } }