/*
 * Copyright (c) 2012, 2015, 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
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 */
package org.graalvm.compiler.hotspot.nodes;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;

import java.util.BitSet;

import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.lir.VirtualStackSlot;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.FixedWithNextNode;
import org.graalvm.compiler.nodes.spi.LIRLowerable;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
import org.graalvm.compiler.word.Word;
import org.graalvm.compiler.word.WordTypes;

import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.Value;

Reserves a block of memory in the stack frame of a method. The block is reserved in the frame for
the entire execution of the associated method.
/**
 * Reserves a block of memory in the stack frame of a method. The block is reserved in the frame for
 * the entire execution of the associated method.
 */
@NodeInfo(cycles = CYCLES_2, size = SIZE_1)
public final class AllocaNode extends FixedWithNextNode implements LIRLowerable {

    public static final NodeClass<AllocaNode> TYPE = NodeClass.create(AllocaNode.class);
    
The number of slots in block.
/**
     * The number of slots in block.
     */
    protected final int slots;

    
The indexes of the object pointer slots in the block. Each such object pointer slot must be
initialized before any safepoint in the method otherwise the garbage collector will see
garbage values when processing these slots.
/**
     * The indexes of the object pointer slots in the block. Each such object pointer slot must be
     * initialized before any safepoint in the method otherwise the garbage collector will see
     * garbage values when processing these slots.
     */
    protected final BitSet objects;

    public AllocaNode(@InjectedNodeParameter WordTypes wordTypes, int slots) {
        this(slots, wordTypes.getWordKind(), new BitSet());
    }

    public AllocaNode(int slots, JavaKind wordKind, BitSet objects) {
        super(TYPE, StampFactory.forKind(wordKind));
        this.slots = slots;
        this.objects = objects;
    }

    @Override
    public void generate(NodeLIRBuilderTool gen) {
        VirtualStackSlot array = gen.getLIRGeneratorTool().getResult().getFrameMapBuilder().allocateStackSlots(slots, objects, null);
        Value result = gen.getLIRGeneratorTool().emitAddress(array);
        gen.setResult(this, result);
    }

    @NodeIntrinsic
    public static native Word alloca(@ConstantNodeParameter int slots);
}