/*
 * 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.nodes.memory;

import org.graalvm.compiler.core.common.LIRKind;
import org.graalvm.compiler.core.common.type.Stamp;
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.ValueNode;
import org.graalvm.compiler.nodes.memory.address.AddressNode;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
import jdk.internal.vm.compiler.word.LocationIdentity;

/**
 * Writes a given {@linkplain #value() value} a {@linkplain FixedAccessNode memory location}.
 */
@NodeInfo(nameTemplate = "Write#{p#location/s}")
public class WriteNode extends AbstractWriteNode implements LIRLowerableAccess, Canonicalizable {

    public static final NodeClass<WriteNode> TYPE = NodeClass.create(WriteNode.class);
    private final boolean volatileAccess;

    public WriteNode(AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType, boolean volatileAccess) {
        super(TYPE, address, location, value, barrierType);
        this.volatileAccess = volatileAccess;
    }

    protected WriteNode(NodeClass<? extends WriteNode> c, AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType) {
        super(c, address, location, value, barrierType);
        this.volatileAccess = false;
    }

    @Override
    public void generate(NodeLIRBuilderTool gen) {
        LIRKind writeKind = gen.getLIRGeneratorTool().getLIRKind(value().stamp(NodeView.DEFAULT));
        gen.getLIRGeneratorTool().getArithmetic().emitStore(writeKind, gen.operand(address), gen.operand(value()), gen.state(this));
    }

    @Override
    public boolean canNullCheck() {
        return !isVolatile();
    }

    @Override
    public Stamp getAccessStamp() {
        return value().stamp(NodeView.DEFAULT);
    }

    @Override
    public Node canonical(CanonicalizerTool tool) {
        if (tool.canonicalizeReads() && hasExactlyOneUsage() && next() instanceof WriteNode) {
            WriteNode write = (WriteNode) next();
            if (write.lastLocationAccess == this && write.getAddress() == getAddress() && getAccessStamp().isCompatible(write.getAccessStamp()) && !isVolatile()) {
                write.setLastLocationAccess(getLastLocationAccess());
                return write;
            }
        }
        return this;
    }

    @Override
    public LocationIdentity getKilledLocationIdentity() {
        if (isVolatile()) {
            return LocationIdentity.any();
        }
        return getLocationIdentity();
    }

    public boolean isVolatile() {
        return volatileAccess;
    }
}