/*
 * Copyright (c) 2009, 2011, 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 com.oracle.graal.nodes.java;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.spi.*;
import com.oracle.graal.nodes.type.*;

/**
 * The {@code StoreIndexedNode} represents a write to an array element.
 */
public final class StoreIndexedNode extends AccessIndexedNode implements StateSplit, Lowerable, Virtualizable {

    @Input private ValueNode value;
    @Input(notDataflow = true) private FrameState stateAfter;

    public FrameState stateAfter() {
        return stateAfter;
    }

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

    public boolean hasSideEffect() {
        return true;
    }

    public ValueNode value() {
        return value;
    }

    /**
     * Creates a new StoreIndexedNode.
     * 
     * @param array the node producing the array
     * @param index the node producing the index
     * @param elementKind the element type
     * @param value the value to store into the array
     */
    public StoreIndexedNode(ValueNode array, ValueNode index, Kind elementKind, ValueNode value) {
        super(StampFactory.forVoid(), array, index, elementKind);
        this.value = value;
    }

    @Override
    public void virtualize(VirtualizerTool tool) {
        State arrayState = tool.getObjectState(array());
        if (arrayState != null && arrayState.getState() == EscapeState.Virtual) {
            ValueNode indexValue = tool.getReplacedValue(index());
            int index = indexValue.isConstant() ? indexValue.asConstant().asInt() : -1;
            if (index >= 0 && index < arrayState.getVirtualObject().entryCount()) {
                ResolvedJavaType componentType = arrayState.getVirtualObject().type().getComponentType();
                if (componentType.isPrimitive() || ObjectStamp.isObjectAlwaysNull(value) || componentType.getSuperclass() == null ||
                                (ObjectStamp.typeOrNull(value) != null && componentType.isAssignableFrom(ObjectStamp.typeOrNull(value)))) {
                    tool.setVirtualEntry(arrayState, index, value());
                    tool.delete();
                }
            }
        }
    }

    public FrameState getState() {
        return stateAfter;
    }
}