/*

 * Copyright (c) 2011, 2017, 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.virtual.phases.ea;

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

import java.util.List;

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

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.graph.spi.CanonicalizerTool;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.FixedNode;

import org.graalvm.compiler.nodes.FixedWithNextNode;

import org.graalvm.compiler.nodes.NodeView;

import org.graalvm.compiler.nodes.ValueNode;

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

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

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

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

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

import org.graalvm.compiler.nodes.virtual.VirtualInstanceNode;

import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;

import org.graalvm.compiler.options.OptionValues;

import jdk.vm.ci.meta.Assumptions;

import jdk.vm.ci.meta.ConstantReflectionProvider;

import jdk.vm.ci.meta.JavaConstant;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.MetaAccessProvider;

/**

 * Forwards calls from {@link VirtualizerTool} to the actual {@link PartialEscapeBlockState}.

 */

class VirtualizerToolImpl implements VirtualizerTool, CanonicalizerTool {

    private final MetaAccessProvider metaAccess;

    private final ConstantReflectionProvider constantReflection;

    private final ConstantFieldProvider constantFieldProvider;

    private final PartialEscapeClosure<?> closure;

    private final Assumptions assumptions;

    private final OptionValues options;

    private final DebugContext debug;

    private final LoweringProvider loweringProvider;

    private ConstantNode illegalConstant;

    VirtualizerToolImpl(MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection, ConstantFieldProvider constantFieldProvider, PartialEscapeClosure<?> closure,

                    Assumptions assumptions, OptionValues options, DebugContext debug, LoweringProvider loweringProvider) {

        this.metaAccess = metaAccess;

        this.constantReflection = constantReflection;

        this.constantFieldProvider = constantFieldProvider;

        this.closure = closure;

        this.assumptions = assumptions;

        this.options = options;

        this.debug = debug;

        this.loweringProvider = loweringProvider;

    }

    private boolean deleted;

    private PartialEscapeBlockState<?> state;

    private ValueNode current;

    private FixedNode position;

    private GraphEffectList effects;

    @Override

    public OptionValues getOptions() {

        return options;

    }

    @Override

    public DebugContext getDebug() {

        return debug;

    }

    @Override

    public MetaAccessProvider getMetaAccessProvider() {

        return metaAccess;

    }

    @Override

    public ConstantReflectionProvider getConstantReflectionProvider() {

        return constantReflection;

    }

    @Override

    public ConstantFieldProvider getConstantFieldProvider() {

        return constantFieldProvider;

    }

    public void reset(PartialEscapeBlockState<?> newState, ValueNode newCurrent, FixedNode newPosition, GraphEffectList newEffects) {

        deleted = false;

        state = newState;

        current = newCurrent;

        position = newPosition;

        effects = newEffects;

    }

    public boolean isDeleted() {

        return deleted;

    }

    @Override

    public ValueNode getAlias(ValueNode value) {

        return closure.getAliasAndResolve(state, value);

    }

    @Override

    public ValueNode getEntry(VirtualObjectNode virtualObject, int index) {

        return state.getObjectState(virtualObject).getEntry(index);

    }

    @Override

    public boolean setVirtualEntry(VirtualObjectNode virtual, int index, ValueNode value, JavaKind theAccessKind, long offset) {

        ObjectState obj = state.getObjectState(virtual);

        assert obj.isVirtual() : "not virtual: " + obj;

        ValueNode newValue;

        JavaKind entryKind = virtual.entryKind(index);

        JavaKind accessKind = theAccessKind != null ? theAccessKind : entryKind;

        if (value == null) {

            newValue = null;

        } else {

            newValue = closure.getAliasAndResolve(state, value);

        }

        getDebug().log(DebugContext.DETAILED_LEVEL, "Setting entry %d in virtual object %s %s results in %s", index, virtual.getObjectId(), virtual, state.getObjectState(virtual.getObjectId()));

        ValueNode oldValue = getEntry(virtual, index);

        boolean canVirtualize = entryKind == accessKind || (entryKind == accessKind.getStackKind() && virtual instanceof VirtualInstanceNode);

        if (!canVirtualize) {

            if (entryKind == JavaKind.Long && oldValue.getStackKind() == newValue.getStackKind() && oldValue.getStackKind().isPrimitive()) {

                /*

                 * Special case: If the entryKind is long, allow arbitrary kinds as long as a value

                 * of the same kind is already there. This can only happen if some other node

                 * initialized the entry with a value of a different kind. One example where this

                 * happens is the Truffle NewFrameNode.

                 */

                getDebug().log(DebugContext.DETAILED_LEVEL, "virtualizing %s with primitive of kind %s in long entry ", current, oldValue.getStackKind());

                canVirtualize = true;

            } else if (entryKind == JavaKind.Int && (accessKind == JavaKind.Long || accessKind == JavaKind.Double) && offset % 8 == 0) {

                /*

                 * Special case: Allow storing a single long or double value into two consecutive

                 * int slots.

                 */

                if (nextIndex != -1) {

                    canVirtualize = true;

                    assert nextIndex == index + 1 : "expected to be sequential";

                    getDebug().log(DebugContext.DETAILED_LEVEL, "virtualizing %s for double word stored in two ints", current);

                }

            }

        }

        if (canVirtualize) {

            getDebug().log(DebugContext.DETAILED_LEVEL, "virtualizing %s for entryKind %s and access kind %s", current, entryKind, accessKind);

            state.setEntry(virtual.getObjectId(), index, newValue);

            if (entryKind == JavaKind.Int) {

                if (accessKind.needsTwoSlots()) {

                    // Storing double word value two int slots

                    assert virtual.entryKind(index + 1) == JavaKind.Int;

                    state.setEntry(virtual.getObjectId(), index + 1, getIllegalConstant());

                } else if (oldValue.getStackKind() == JavaKind.Double || oldValue.getStackKind() == JavaKind.Long) {

                    // Splitting double word constant by storing over it with an int

                    getDebug().log(DebugContext.DETAILED_LEVEL, "virtualizing %s producing second half of double word value %s", current, oldValue);

                    ValueNode secondHalf = UnpackEndianHalfNode.create(oldValue, false, NodeView.DEFAULT);

                    addNode(secondHalf);

                    state.setEntry(virtual.getObjectId(), index + 1, secondHalf);

                }

            }

            if (oldValue.isConstant() && oldValue.asConstant().equals(JavaConstant.forIllegal())) {

                // Storing into second half of double, so replace previous value

                ValueNode previous = getEntry(virtual, index - 1);

                getDebug().log(DebugContext.DETAILED_LEVEL, "virtualizing %s producing first half of double word value %s", current, previous);

                ValueNode firstHalf = UnpackEndianHalfNode.create(previous, true, NodeView.DEFAULT);

                addNode(firstHalf);

                state.setEntry(virtual.getObjectId(), index - 1, firstHalf);

            }

            return true;

        }

        // Should only occur if there are mismatches between the entry and access kind

        assert entryKind != accessKind;

        return false;

    }

    private ValueNode getIllegalConstant() {

        if (illegalConstant == null) {

            illegalConstant = ConstantNode.forConstant(JavaConstant.forIllegal(), getMetaAccessProvider());

            addNode(illegalConstant);

        }

        return illegalConstant;

    }

    @Override

    public void setEnsureVirtualized(VirtualObjectNode virtualObject, boolean ensureVirtualized) {

        int id = virtualObject.getObjectId();

        state.setEnsureVirtualized(id, ensureVirtualized);

    }

    @Override

    public boolean getEnsureVirtualized(VirtualObjectNode virtualObject) {

        return state.getObjectState(virtualObject).getEnsureVirtualized();

    }

    @Override

    public void replaceWithVirtual(VirtualObjectNode virtual) {

        closure.addVirtualAlias(virtual, current);

        effects.deleteNode(current);

        deleted = true;

    }

    @Override

    public void replaceWithValue(ValueNode replacement) {

        effects.replaceAtUsages(current, closure.getScalarAlias(replacement), position);

        closure.addScalarAlias(current, replacement);

        deleted = true;

    }

    @Override

    public void delete() {

        effects.deleteNode(current);

        deleted = true;

    }

    @Override

    public void replaceFirstInput(Node oldInput, Node replacement) {

        effects.replaceFirstInput(current, oldInput, replacement);

    }

    @Override

    public void addNode(ValueNode node) {

        if (node instanceof FloatingNode) {

            effects.addFloatingNode(node, "VirtualizerTool");

        } else {

            effects.addFixedNodeBefore((FixedWithNextNode) node, position);

        }

    }

    @Override

    public void createVirtualObject(VirtualObjectNode virtualObject, ValueNode[] entryState, List<MonitorIdNode> locks, boolean ensureVirtualized) {

        VirtualUtil.trace(options, debug, "{{%s}} ", current);

        if (!virtualObject.isAlive()) {

            effects.addFloatingNode(virtualObject, "newVirtualObject");

        }

        for (int i = 0; i < entryState.length; i++) {

            ValueNode entry = entryState[i];

            entryState[i] = entry instanceof VirtualObjectNode ? entry : closure.getAliasAndResolve(state, entry);

        }

        int id = virtualObject.getObjectId();

        if (id == -1) {

            id = closure.virtualObjects.size();

            closure.virtualObjects.add(virtualObject);

            virtualObject.setObjectId(id);

        }

        state.addObject(id, new ObjectState(entryState, locks, ensureVirtualized));

        closure.addVirtualAlias(virtualObject, virtualObject);

        PartialEscapeClosure.COUNTER_ALLOCATION_REMOVED.increment(debug);

        effects.addVirtualizationDelta(1);

    }

    @Override

    public int getMaximumEntryCount() {

        return MaximumEscapeAnalysisArrayLength.getValue(current.getOptions());

    }

    @Override

    public void replaceWith(ValueNode node) {

        if (node instanceof VirtualObjectNode) {

            replaceWithVirtual((VirtualObjectNode) node);

        } else {

            replaceWithValue(node);

        }

    }

    @Override

    public boolean ensureMaterialized(VirtualObjectNode virtualObject) {

        return closure.ensureMaterialized(state, virtualObject.getObjectId(), position, effects, PartialEscapeClosure.COUNTER_MATERIALIZATIONS_UNHANDLED);

    }

    @Override

    public void addLock(VirtualObjectNode virtualObject, MonitorIdNode monitorId) {

        int id = virtualObject.getObjectId();

        state.addLock(id, monitorId);

    }

    @Override

    public MonitorIdNode removeLock(VirtualObjectNode virtualObject) {

        int id = virtualObject.getObjectId();

        return state.removeLock(id);

    }

    @Override

    public MetaAccessProvider getMetaAccess() {

        return metaAccess;

    }

    @Override

    public ConstantReflectionProvider getConstantReflection() {

        return constantReflection;

    }

    @Override

    public boolean canonicalizeReads() {

        return false;

    }

    @Override

    public boolean allUsagesAvailable() {

        return true;

    }

    @Override

    public Assumptions getAssumptions() {

        return assumptions;

    }

    @Override

    public Integer smallestCompareWidth() {

        if (loweringProvider != null) {

            return loweringProvider.smallestCompareWidth();

        } else {

            return null;

        }

    }

}