/*
 * Copyright (c) 2011, 2016, 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.nodes.memory;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_3;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;

import org.graalvm.compiler.core.common.LocationIdentity;
import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.nodeinfo.InputType;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.FrameState;
import org.graalvm.compiler.nodes.StateSplit;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.ValueNodeUtil;
import org.graalvm.compiler.nodes.extended.GuardingNode;
import org.graalvm.compiler.nodes.memory.address.AddressNode;

@NodeInfo(allowedUsageTypes = {InputType.Memory, InputType.Guard}, cycles = CYCLES_3, size = SIZE_1)
public abstract class AbstractWriteNode extends FixedAccessNode implements StateSplit, MemoryCheckpoint.Single, MemoryAccess, GuardingNode {

    public static final NodeClass<AbstractWriteNode> TYPE = NodeClass.create(AbstractWriteNode.class);
    @Input ValueNode value;
    @OptionalInput(InputType.State) FrameState stateAfter;
    @OptionalInput(InputType.Memory) Node lastLocationAccess;

    protected final boolean initialization;

    @Override
    public FrameState stateAfter() {
        return stateAfter;
    }

    @Override
    public void setStateAfter(FrameState x) {
        assert x == null || x.isAlive() : "frame state must be in a graph";
        updateUsages(stateAfter, x);
        stateAfter = x;
    }

    @Override
    public boolean hasSideEffect() {
        return true;
    }

    public ValueNode value() {
        return value;
    }

    
Returns whether this write is the initialization of the written location. If it is true, the
old value of the memory location is either uninitialized or zero. If it is false, the memory
location is guaranteed to contain a valid value or zero.
/**
     * Returns whether this write is the initialization of the written location. If it is true, the
     * old value of the memory location is either uninitialized or zero. If it is false, the memory
     * location is guaranteed to contain a valid value or zero.
     */
    public boolean isInitialization() {
        return initialization;
    }

    protected AbstractWriteNode(NodeClass<? extends AbstractWriteNode> c, AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType) {
        this(c, address, location, value, barrierType, false);
    }

    protected AbstractWriteNode(NodeClass<? extends AbstractWriteNode> c, AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType, boolean initialization) {
        super(c, address, location, StampFactory.forVoid(), barrierType);
        this.value = value;
        this.initialization = initialization;
    }

    protected AbstractWriteNode(NodeClass<? extends AbstractWriteNode> c, AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType, GuardingNode guard,
                    boolean initialization) {
        super(c, address, location, StampFactory.forVoid(), guard, barrierType, false, null);
        this.value = value;
        this.initialization = initialization;
    }

    @Override
    public boolean isAllowedUsageType(InputType type) {
        return (type == InputType.Guard && getNullCheck()) ? true : super.isAllowedUsageType(type);
    }

    @Override
    public MemoryNode getLastLocationAccess() {
        return (MemoryNode) lastLocationAccess;
    }

    @Override
    public void setLastLocationAccess(MemoryNode lla) {
        Node newLla = ValueNodeUtil.asNode(lla);
        updateUsages(lastLocationAccess, newLla);
        lastLocationAccess = newLla;
    }
}