/*

 * Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved.

 * 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package org.graalvm.compiler.hotspot.meta;

import static jdk.vm.ci.services.Services.IS_IN_NATIVE_IMAGE;

import static org.graalvm.compiler.core.common.GraalOptions.AlwaysInlineVTableStubs;

import static org.graalvm.compiler.core.common.GraalOptions.InlineVTableStubs;

import static org.graalvm.compiler.core.common.GraalOptions.OmitHotExceptionStacktrace;

import static org.graalvm.compiler.hotspot.meta.HotSpotForeignCallsProviderImpl.OSR_MIGRATION_END;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.CLASS_KLASS_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.CLASS_MIRROR_HANDLE_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.CLASS_MIRROR_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.COMPRESSED_HUB_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.DISPLACED_MARK_WORD_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.HUB_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.HUB_WRITE_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.KLASS_LAYOUT_HELPER_LOCATION;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.OBJ_ARRAY_KLASS_ELEMENT_KLASS_LOCATION;

import static jdk.internal.vm.compiler.word.LocationIdentity.any;

import java.lang.ref.Reference;

import java.util.EnumMap;

import org.graalvm.compiler.api.directives.GraalDirectives;

import org.graalvm.compiler.core.common.CompressEncoding;

import org.graalvm.compiler.core.common.GraalOptions;

import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;

import org.graalvm.compiler.core.common.spi.ForeignCallsProvider;

import org.graalvm.compiler.core.common.type.ObjectStamp;

import org.graalvm.compiler.core.common.type.Stamp;

import org.graalvm.compiler.core.common.type.StampFactory;

import org.graalvm.compiler.core.common.type.StampPair;

import org.graalvm.compiler.debug.DebugCloseable;

import org.graalvm.compiler.debug.DebugHandlersFactory;

import org.graalvm.compiler.debug.GraalError;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.graph.NodeInputList;

import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;

import org.graalvm.compiler.hotspot.HotSpotGraalRuntimeProvider;

import org.graalvm.compiler.hotspot.nodes.BeginLockScopeNode;

import org.graalvm.compiler.hotspot.nodes.HotSpotCompressionNode;

import org.graalvm.compiler.hotspot.nodes.HotSpotDirectCallTargetNode;

import org.graalvm.compiler.hotspot.nodes.HotSpotIndirectCallTargetNode;

import org.graalvm.compiler.hotspot.nodes.KlassBeingInitializedCheckNode;

import org.graalvm.compiler.hotspot.nodes.aot.InitializeKlassNode;

import org.graalvm.compiler.hotspot.nodes.aot.ResolveConstantNode;

import org.graalvm.compiler.hotspot.nodes.aot.ResolveDynamicConstantNode;

import org.graalvm.compiler.hotspot.nodes.aot.ResolveMethodAndLoadCountersNode;

import org.graalvm.compiler.hotspot.nodes.profiling.ProfileNode;

import org.graalvm.compiler.hotspot.nodes.type.HotSpotNarrowOopStamp;

import org.graalvm.compiler.hotspot.nodes.type.KlassPointerStamp;

import org.graalvm.compiler.hotspot.nodes.type.MethodPointerStamp;

import org.graalvm.compiler.hotspot.replacements.AssertionSnippets;

import org.graalvm.compiler.hotspot.replacements.ClassGetHubNode;

import org.graalvm.compiler.hotspot.replacements.HashCodeSnippets;

import org.graalvm.compiler.hotspot.replacements.HotSpotG1WriteBarrierSnippets;

import org.graalvm.compiler.hotspot.replacements.HotSpotSerialWriteBarrierSnippets;

import org.graalvm.compiler.hotspot.replacements.HubGetClassNode;

import org.graalvm.compiler.hotspot.replacements.IdentityHashCodeNode;

import org.graalvm.compiler.hotspot.replacements.InstanceOfSnippets;

import org.graalvm.compiler.hotspot.replacements.KlassLayoutHelperNode;

import org.graalvm.compiler.hotspot.replacements.LoadExceptionObjectSnippets;

import org.graalvm.compiler.hotspot.replacements.MonitorSnippets;

import org.graalvm.compiler.hotspot.replacements.NewObjectSnippets;

import org.graalvm.compiler.hotspot.replacements.ObjectCloneSnippets;

import org.graalvm.compiler.hotspot.replacements.StringToBytesSnippets;

import org.graalvm.compiler.hotspot.replacements.UnsafeLoadSnippets;

import org.graalvm.compiler.hotspot.replacements.aot.ResolveConstantSnippets;

import org.graalvm.compiler.hotspot.replacements.arraycopy.HotSpotArraycopySnippets;

import org.graalvm.compiler.hotspot.replacements.profiling.ProfileSnippets;

import org.graalvm.compiler.hotspot.stubs.ForeignCallSnippets;

import org.graalvm.compiler.hotspot.word.KlassPointer;

import org.graalvm.compiler.nodes.AbstractBeginNode;

import org.graalvm.compiler.nodes.AbstractDeoptimizeNode;

import org.graalvm.compiler.nodes.CompressionNode.CompressionOp;

import org.graalvm.compiler.nodes.ComputeObjectAddressNode;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.FixedNode;

import org.graalvm.compiler.nodes.GetObjectAddressNode;

import org.graalvm.compiler.nodes.Invoke;

import org.graalvm.compiler.nodes.LogicNode;

import org.graalvm.compiler.nodes.LoweredCallTargetNode;

import org.graalvm.compiler.nodes.NodeView;

import org.graalvm.compiler.nodes.ParameterNode;

import org.graalvm.compiler.nodes.SafepointNode;

import org.graalvm.compiler.nodes.StartNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.UnwindNode;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.calc.AddNode;

import org.graalvm.compiler.nodes.calc.FloatingNode;

import org.graalvm.compiler.nodes.calc.IntegerDivRemNode;

import org.graalvm.compiler.nodes.calc.IsNullNode;

import org.graalvm.compiler.nodes.calc.RemNode;

import org.graalvm.compiler.nodes.debug.StringToBytesNode;

import org.graalvm.compiler.nodes.debug.VerifyHeapNode;

import org.graalvm.compiler.nodes.extended.BytecodeExceptionNode;

import org.graalvm.compiler.nodes.extended.BytecodeExceptionNode.BytecodeExceptionKind;

import org.graalvm.compiler.nodes.extended.ForeignCallNode;

import org.graalvm.compiler.nodes.extended.GetClassNode;

import org.graalvm.compiler.nodes.extended.GuardedUnsafeLoadNode;

import org.graalvm.compiler.nodes.extended.LoadHubNode;

import org.graalvm.compiler.nodes.extended.LoadMethodNode;

import org.graalvm.compiler.nodes.extended.OSRLocalNode;

import org.graalvm.compiler.nodes.extended.OSRLockNode;

import org.graalvm.compiler.nodes.extended.OSRMonitorEnterNode;

import org.graalvm.compiler.nodes.extended.OSRStartNode;

import org.graalvm.compiler.nodes.extended.RawLoadNode;

import org.graalvm.compiler.nodes.extended.StoreHubNode;

import org.graalvm.compiler.nodes.gc.G1ArrayRangePostWriteBarrier;

import org.graalvm.compiler.nodes.gc.G1ArrayRangePreWriteBarrier;

import org.graalvm.compiler.nodes.gc.G1PostWriteBarrier;

import org.graalvm.compiler.nodes.gc.G1PreWriteBarrier;

import org.graalvm.compiler.nodes.gc.G1ReferentFieldReadBarrier;

import org.graalvm.compiler.nodes.gc.SerialArrayRangeWriteBarrier;

import org.graalvm.compiler.nodes.gc.SerialWriteBarrier;

import org.graalvm.compiler.nodes.java.ClassIsAssignableFromNode;

import org.graalvm.compiler.nodes.java.DynamicNewArrayNode;

import org.graalvm.compiler.nodes.java.DynamicNewInstanceNode;

import org.graalvm.compiler.nodes.java.InstanceOfDynamicNode;

import org.graalvm.compiler.nodes.java.InstanceOfNode;

import org.graalvm.compiler.nodes.java.LoadExceptionObjectNode;

import org.graalvm.compiler.nodes.java.MethodCallTargetNode;

import org.graalvm.compiler.nodes.java.MonitorExitNode;

import org.graalvm.compiler.nodes.java.MonitorIdNode;

import org.graalvm.compiler.nodes.java.NewArrayNode;

import org.graalvm.compiler.nodes.java.NewInstanceNode;

import org.graalvm.compiler.nodes.java.NewMultiArrayNode;

import org.graalvm.compiler.nodes.java.RawMonitorEnterNode;

import org.graalvm.compiler.nodes.memory.FloatingReadNode;

import org.graalvm.compiler.nodes.memory.HeapAccess.BarrierType;

import org.graalvm.compiler.nodes.memory.ReadNode;

import org.graalvm.compiler.nodes.memory.WriteNode;

import org.graalvm.compiler.nodes.memory.address.AddressNode;

import org.graalvm.compiler.nodes.spi.LoweringProvider;

import org.graalvm.compiler.nodes.spi.LoweringTool;

import org.graalvm.compiler.nodes.spi.StampProvider;

import org.graalvm.compiler.nodes.type.StampTool;

import org.graalvm.compiler.nodes.util.GraphUtil;

import org.graalvm.compiler.options.OptionValues;

import org.graalvm.compiler.replacements.DefaultJavaLoweringProvider;

import org.graalvm.compiler.replacements.arraycopy.ArrayCopyNode;

import org.graalvm.compiler.replacements.arraycopy.ArrayCopySnippets;

import org.graalvm.compiler.replacements.arraycopy.ArrayCopyWithDelayedLoweringNode;

import org.graalvm.compiler.replacements.nodes.AssertionNode;

import org.graalvm.compiler.serviceprovider.JavaVersionUtil;

import jdk.internal.vm.compiler.word.LocationIdentity;

import jdk.vm.ci.code.TargetDescription;

import jdk.vm.ci.hotspot.HotSpotCallingConventionType;

import jdk.vm.ci.hotspot.HotSpotConstantReflectionProvider;

import jdk.vm.ci.hotspot.HotSpotResolvedJavaField;

import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;

import jdk.vm.ci.meta.JavaConstant;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.JavaType;

import jdk.vm.ci.meta.MetaAccessProvider;

import jdk.vm.ci.meta.ResolvedJavaField;

import jdk.vm.ci.meta.ResolvedJavaType;

/**

 * HotSpot implementation of {@link LoweringProvider}.

 */

public abstract class DefaultHotSpotLoweringProvider extends DefaultJavaLoweringProvider implements HotSpotLoweringProvider {

    protected final HotSpotGraalRuntimeProvider runtime;

    protected final HotSpotRegistersProvider registers;

    protected final HotSpotConstantReflectionProvider constantReflection;

    protected InstanceOfSnippets.Templates instanceofSnippets;

    protected NewObjectSnippets.Templates newObjectSnippets;

    protected MonitorSnippets.Templates monitorSnippets;

    protected HotSpotSerialWriteBarrierSnippets.Templates serialWriteBarrierSnippets;

    protected HotSpotG1WriteBarrierSnippets.Templates g1WriteBarrierSnippets;

    protected LoadExceptionObjectSnippets.Templates exceptionObjectSnippets;

    protected UnsafeLoadSnippets.Templates unsafeLoadSnippets;

    protected AssertionSnippets.Templates assertionSnippets;

    protected ArrayCopySnippets.Templates arraycopySnippets;

    protected StringToBytesSnippets.Templates stringToBytesSnippets;

    protected HashCodeSnippets.Templates hashCodeSnippets;

    protected ResolveConstantSnippets.Templates resolveConstantSnippets;

    protected ProfileSnippets.Templates profileSnippets;

    protected ObjectCloneSnippets.Templates objectCloneSnippets;

    protected ForeignCallSnippets.Templates foreignCallSnippets;

    public DefaultHotSpotLoweringProvider(HotSpotGraalRuntimeProvider runtime, MetaAccessProvider metaAccess, ForeignCallsProvider foreignCalls, HotSpotRegistersProvider registers,

                    HotSpotConstantReflectionProvider constantReflection, TargetDescription target) {

        super(metaAccess, foreignCalls, target, runtime.getVMConfig().useCompressedOops);

        this.runtime = runtime;

        this.registers = registers;

        this.constantReflection = constantReflection;

    }

    @Override

    public void initialize(OptionValues options, Iterable<DebugHandlersFactory> factories, HotSpotProviders providers, GraalHotSpotVMConfig config) {

        super.initialize(options, factories, runtime, providers, providers.getSnippetReflection());

        assert target == providers.getCodeCache().getTarget();

        instanceofSnippets = new InstanceOfSnippets.Templates(options, factories, runtime, providers, target);

        newObjectSnippets = new NewObjectSnippets.Templates(options, factories, runtime, providers, target, config);

        monitorSnippets = new MonitorSnippets.Templates(options, factories, runtime, providers, target, config.useFastLocking);

        g1WriteBarrierSnippets = new HotSpotG1WriteBarrierSnippets.Templates(options, factories, runtime, providers, target, config);

        serialWriteBarrierSnippets = new HotSpotSerialWriteBarrierSnippets.Templates(options, factories, runtime, providers, target, config);

        exceptionObjectSnippets = new LoadExceptionObjectSnippets.Templates(options, factories, providers, target);

        unsafeLoadSnippets = new UnsafeLoadSnippets.Templates(options, factories, providers, target);

        assertionSnippets = new AssertionSnippets.Templates(options, factories, providers, target);

        arraycopySnippets = new ArrayCopySnippets.Templates(new HotSpotArraycopySnippets(), options, factories, runtime, providers, providers.getSnippetReflection(), target);

        stringToBytesSnippets = new StringToBytesSnippets.Templates(options, factories, providers, target);

        hashCodeSnippets = new HashCodeSnippets.Templates(options, factories, providers, target);

        resolveConstantSnippets = new ResolveConstantSnippets.Templates(options, factories, providers, target);

        objectCloneSnippets = new ObjectCloneSnippets.Templates(options, factories, providers, target);

        foreignCallSnippets = new ForeignCallSnippets.Templates(options, factories, providers, target);

        if (JavaVersionUtil.JAVA_SPEC <= 8) {

            // AOT only introduced in JDK 9

            profileSnippets = null;

        } else {

            profileSnippets = new ProfileSnippets.Templates(options, factories, providers, target);

        }

    }

    public ArrayCopySnippets.Templates getArraycopySnippets() {

        return arraycopySnippets;

    }

    public MonitorSnippets.Templates getMonitorSnippets() {

        return monitorSnippets;

    }

    @Override

    @SuppressWarnings("try")

    public void lower(Node n, LoweringTool tool) {

        StructuredGraph graph = (StructuredGraph) n.graph();

        try (DebugCloseable context = n.withNodeSourcePosition()) {

            if (n instanceof Invoke) {

                lowerInvoke((Invoke) n, tool, graph);

            } else if (n instanceof LoadMethodNode) {

                lowerLoadMethodNode((LoadMethodNode) n);

            } else if (n instanceof GetClassNode) {

                lowerGetClassNode((GetClassNode) n, tool, graph);

            } else if (n instanceof StoreHubNode) {

                lowerStoreHubNode((StoreHubNode) n, graph);

            } else if (n instanceof OSRStartNode) {

                lowerOSRStartNode((OSRStartNode) n);

            } else if (n instanceof BytecodeExceptionNode) {

                lowerBytecodeExceptionNode((BytecodeExceptionNode) n);

            } else if (n instanceof InstanceOfNode) {

                InstanceOfNode instanceOfNode = (InstanceOfNode) n;

                if (graph.getGuardsStage().areDeoptsFixed()) {

                    instanceofSnippets.lower(instanceOfNode, tool);

                } else {

                    if (instanceOfNode.allowsNull()) {

                        ValueNode object = instanceOfNode.getValue();

                        LogicNode newTypeCheck = graph.addOrUniqueWithInputs(InstanceOfNode.create(instanceOfNode.type(), object, instanceOfNode.profile(), instanceOfNode.getAnchor()));

                        LogicNode newNode = LogicNode.or(graph.unique(IsNullNode.create(object)), newTypeCheck, GraalDirectives.UNLIKELY_PROBABILITY);

                        instanceOfNode.replaceAndDelete(newNode);

                    }

                }

            } else if (n instanceof InstanceOfDynamicNode) {

                InstanceOfDynamicNode instanceOfDynamicNode = (InstanceOfDynamicNode) n;

                if (graph.getGuardsStage().areDeoptsFixed()) {

                    instanceofSnippets.lower(instanceOfDynamicNode, tool);

                } else {

                    ValueNode mirror = instanceOfDynamicNode.getMirrorOrHub();

                    if (mirror.stamp(NodeView.DEFAULT).getStackKind() == JavaKind.Object) {

                        ClassGetHubNode classGetHub = graph.unique(new ClassGetHubNode(mirror));

                        instanceOfDynamicNode.setMirror(classGetHub);

                    }

                    if (instanceOfDynamicNode.allowsNull()) {

                        ValueNode object = instanceOfDynamicNode.getObject();

                        LogicNode newTypeCheck = graph.addOrUniqueWithInputs(

                                        InstanceOfDynamicNode.create(graph.getAssumptions(), tool.getConstantReflection(), instanceOfDynamicNode.getMirrorOrHub(), object, false));

                        LogicNode newNode = LogicNode.or(graph.unique(IsNullNode.create(object)), newTypeCheck, GraalDirectives.UNLIKELY_PROBABILITY);

                        instanceOfDynamicNode.replaceAndDelete(newNode);

                    }

                }

            } else if (n instanceof ClassIsAssignableFromNode) {

                if (graph.getGuardsStage().areDeoptsFixed()) {

                    instanceofSnippets.lower((ClassIsAssignableFromNode) n, tool);

                }

            } else if (n instanceof NewInstanceNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    newObjectSnippets.lower((NewInstanceNode) n, registers, tool);

                }

            } else if (n instanceof DynamicNewInstanceNode) {

                DynamicNewInstanceNode newInstanceNode = (DynamicNewInstanceNode) n;

                if (newInstanceNode.getClassClass() == null) {

                    JavaConstant classClassMirror = constantReflection.asJavaClass(metaAccess.lookupJavaType(Class.class));

                    ConstantNode classClass = ConstantNode.forConstant(classClassMirror, tool.getMetaAccess(), graph);

                    newInstanceNode.setClassClass(classClass);

                }

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    newObjectSnippets.lower(newInstanceNode, registers, tool);

                }

            } else if (n instanceof NewArrayNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    newObjectSnippets.lower((NewArrayNode) n, registers, tool);

                }

            } else if (n instanceof DynamicNewArrayNode) {

                DynamicNewArrayNode dynamicNewArrayNode = (DynamicNewArrayNode) n;

                if (dynamicNewArrayNode.getVoidClass() == null) {

                    JavaConstant voidClassMirror = constantReflection.asJavaClass(metaAccess.lookupJavaType(void.class));

                    ConstantNode voidClass = ConstantNode.forConstant(voidClassMirror, tool.getMetaAccess(), graph);

                    dynamicNewArrayNode.setVoidClass(voidClass);

                }

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    newObjectSnippets.lower(dynamicNewArrayNode, registers, tool);

                }

            } else if (n instanceof VerifyHeapNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    newObjectSnippets.lower((VerifyHeapNode) n, registers, tool);

                }

            } else if (n instanceof RawMonitorEnterNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    monitorSnippets.lower((RawMonitorEnterNode) n, registers, tool);

                }

            } else if (n instanceof MonitorExitNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    monitorSnippets.lower((MonitorExitNode) n, registers, tool);

                }

            } else if (n instanceof ArrayCopyNode) {

                arraycopySnippets.lower((ArrayCopyNode) n, tool);

            } else if (n instanceof ArrayCopyWithDelayedLoweringNode) {

                arraycopySnippets.lower((ArrayCopyWithDelayedLoweringNode) n, tool);

            } else if (n instanceof G1PreWriteBarrier) {

                g1WriteBarrierSnippets.lower((G1PreWriteBarrier) n, tool);

            } else if (n instanceof G1PostWriteBarrier) {

                g1WriteBarrierSnippets.lower((G1PostWriteBarrier) n, tool);

            } else if (n instanceof G1ReferentFieldReadBarrier) {

                g1WriteBarrierSnippets.lower((G1ReferentFieldReadBarrier) n, tool);

            } else if (n instanceof SerialWriteBarrier) {

                serialWriteBarrierSnippets.lower((SerialWriteBarrier) n, tool);

            } else if (n instanceof SerialArrayRangeWriteBarrier) {

                serialWriteBarrierSnippets.lower((SerialArrayRangeWriteBarrier) n, tool);

            } else if (n instanceof G1ArrayRangePreWriteBarrier) {

                g1WriteBarrierSnippets.lower((G1ArrayRangePreWriteBarrier) n, tool);

            } else if (n instanceof G1ArrayRangePostWriteBarrier) {

                g1WriteBarrierSnippets.lower((G1ArrayRangePostWriteBarrier) n, tool);

            } else if (n instanceof NewMultiArrayNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    newObjectSnippets.lower((NewMultiArrayNode) n, tool);

                }

            } else if (n instanceof LoadExceptionObjectNode) {

                exceptionObjectSnippets.lower((LoadExceptionObjectNode) n, registers, tool);

            } else if (n instanceof AssertionNode) {

                assertionSnippets.lower((AssertionNode) n, tool);

            } else if (n instanceof StringToBytesNode) {

                if (graph.getGuardsStage().areDeoptsFixed()) {

                    stringToBytesSnippets.lower((StringToBytesNode) n, tool);

                }

            } else if (n instanceof IntegerDivRemNode) {

                // Nothing to do for division nodes. The HotSpot signal handler catches divisions by

                // zero and the MIN_VALUE / -1 cases.

            } else if (n instanceof AbstractDeoptimizeNode || n instanceof UnwindNode || n instanceof RemNode || n instanceof SafepointNode) {

                /* No lowering, we generate LIR directly for these nodes. */

            } else if (n instanceof ClassGetHubNode) {

                lowerClassGetHubNode((ClassGetHubNode) n, tool);

            } else if (n instanceof HubGetClassNode) {

                lowerHubGetClassNode((HubGetClassNode) n, tool);

            } else if (n instanceof KlassLayoutHelperNode) {

                lowerKlassLayoutHelperNode((KlassLayoutHelperNode) n, tool);

            } else if (n instanceof ComputeObjectAddressNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    lowerComputeObjectAddressNode((ComputeObjectAddressNode) n);

                }

            } else if (n instanceof IdentityHashCodeNode) {

                hashCodeSnippets.lower((IdentityHashCodeNode) n, tool);

            } else if (n instanceof ResolveDynamicConstantNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    resolveConstantSnippets.lower((ResolveDynamicConstantNode) n, tool);

                }

            } else if (n instanceof ResolveConstantNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    resolveConstantSnippets.lower((ResolveConstantNode) n, tool);

                }

            } else if (n instanceof ResolveMethodAndLoadCountersNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    resolveConstantSnippets.lower((ResolveMethodAndLoadCountersNode) n, tool);

                }

            } else if (n instanceof InitializeKlassNode) {

                if (graph.getGuardsStage().areFrameStatesAtDeopts()) {

                    resolveConstantSnippets.lower((InitializeKlassNode) n, tool);

                }

            } else if (n instanceof ProfileNode) {

                profileSnippets.lower((ProfileNode) n, tool);

            } else if (n instanceof KlassBeingInitializedCheckNode) {

                newObjectSnippets.lower((KlassBeingInitializedCheckNode) n, registers, tool);

            } else {

                super.lower(n, tool);

            }

        }

    }

    private static void lowerComputeObjectAddressNode(ComputeObjectAddressNode n) {

        /*

         * Lower the node into a ComputeObjectAddress node and an Add but ensure that it's below any

         * potential safepoints and above it's uses.

         */

        for (Node use : n.usages().snapshot()) {

            if (use instanceof FixedNode) {

                FixedNode fixed = (FixedNode) use;

                StructuredGraph graph = n.graph();

                GetObjectAddressNode address = graph.add(new GetObjectAddressNode(n.getObject()));

                graph.addBeforeFixed(fixed, address);

                AddNode add = graph.addOrUnique(new AddNode(address, n.getOffset()));

                use.replaceFirstInput(n, add);

            } else {

                throw GraalError.shouldNotReachHere("Unexpected floating use of ComputeObjectAddressNode " + n);

            }

        }

        GraphUtil.unlinkFixedNode(n);

        n.safeDelete();

    }

    private void lowerKlassLayoutHelperNode(KlassLayoutHelperNode n, LoweringTool tool) {

        if (tool.getLoweringStage() == LoweringTool.StandardLoweringStage.HIGH_TIER) {

            return;

        }

        StructuredGraph graph = n.graph();

        assert !n.getHub().isConstant();

        AddressNode address = createOffsetAddress(graph, n.getHub(), runtime.getVMConfig().klassLayoutHelperOffset);

        n.replaceAtUsagesAndDelete(graph.unique(new FloatingReadNode(address, KLASS_LAYOUT_HELPER_LOCATION, null, n.stamp(NodeView.DEFAULT), null, BarrierType.NONE)));

    }

    private void lowerHubGetClassNode(HubGetClassNode n, LoweringTool tool) {

        if (tool.getLoweringStage() == LoweringTool.StandardLoweringStage.HIGH_TIER) {

            return;

        }

        ValueNode hub = n.getHub();

        GraalHotSpotVMConfig vmConfig = runtime.getVMConfig();

        StructuredGraph graph = n.graph();

        assert !hub.isConstant() || GraalOptions.ImmutableCode.getValue(graph.getOptions());

        AddressNode mirrorAddress = createOffsetAddress(graph, hub, vmConfig.classMirrorOffset);

        FloatingReadNode read = graph.unique(

                        new FloatingReadNode(mirrorAddress, CLASS_MIRROR_LOCATION, null, vmConfig.classMirrorIsHandle ? StampFactory.forKind(target.wordJavaKind) : n.stamp(NodeView.DEFAULT),

                                        null, BarrierType.NONE));

        if (vmConfig.classMirrorIsHandle) {

            AddressNode address = createOffsetAddress(graph, read, 0);

            read = graph.unique(new FloatingReadNode(address, CLASS_MIRROR_HANDLE_LOCATION, null, n.stamp(NodeView.DEFAULT), null, BarrierType.NONE));

        }

        n.replaceAtUsagesAndDelete(read);

    }

    private void lowerClassGetHubNode(ClassGetHubNode n, LoweringTool tool) {

        if (tool.getLoweringStage() == LoweringTool.StandardLoweringStage.HIGH_TIER) {

            return;

        }

        StructuredGraph graph = n.graph();

        assert !n.getValue().isConstant();

        AddressNode address = createOffsetAddress(graph, n.getValue(), runtime.getVMConfig().klassOffset);

        FloatingReadNode read = graph.unique(new FloatingReadNode(address, CLASS_KLASS_LOCATION, null, n.stamp(NodeView.DEFAULT), null, BarrierType.NONE));

        n.replaceAtUsagesAndDelete(read);

    }

    private void lowerInvoke(Invoke invoke, LoweringTool tool, StructuredGraph graph) {

        if (invoke.callTarget() instanceof MethodCallTargetNode) {

            MethodCallTargetNode callTarget = (MethodCallTargetNode) invoke.callTarget();

            NodeInputList<ValueNode> parameters = callTarget.arguments();

            ValueNode receiver = parameters.isEmpty() ? null : parameters.get(0);

            if (!callTarget.isStatic()) {

                assert receiver != null : "non-static call must have a receiver";

                if (receiver.stamp(NodeView.DEFAULT) instanceof ObjectStamp && !StampTool.isPointerNonNull(receiver)) {

                    ValueNode nonNullReceiver = createNullCheckedValue(receiver, invoke.asNode(), tool);

                    parameters.set(0, nonNullReceiver);

                    receiver = nonNullReceiver;

                }

            }

            JavaType[] signature = callTarget.targetMethod().getSignature().toParameterTypes(callTarget.isStatic() ? null : callTarget.targetMethod().getDeclaringClass());

            LoweredCallTargetNode loweredCallTarget = null;

            OptionValues options = graph.getOptions();

            if (InlineVTableStubs.getValue(options) && callTarget.invokeKind().isIndirect() && (AlwaysInlineVTableStubs.getValue(options) || invoke.isPolymorphic())) {

                HotSpotResolvedJavaMethod hsMethod = (HotSpotResolvedJavaMethod) callTarget.targetMethod();

                ResolvedJavaType receiverType = invoke.getReceiverType();

                if (hsMethod.isInVirtualMethodTable(receiverType)) {

                    JavaKind wordKind = runtime.getTarget().wordJavaKind;