1 /*
   2  * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.hotspot.nodes;
  24 
  25 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
  26 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  27 
  28 import java.util.BitSet;
  29 
  30 import org.graalvm.compiler.core.common.type.StampFactory;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.lir.VirtualStackSlot;
  33 import org.graalvm.compiler.nodeinfo.NodeInfo;
  34 import org.graalvm.compiler.nodes.FixedWithNextNode;
  35 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  36 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  37 import org.graalvm.compiler.word.Word;
  38 import org.graalvm.compiler.word.WordTypes;
  39 
  40 import jdk.vm.ci.meta.JavaKind;
  41 import jdk.vm.ci.meta.Value;
  42 
  43 /**
  44  * Reserves a block of memory in the stack frame of a method. The block is reserved in the frame for
  45  * the entire execution of the associated method.
  46  */
  47 @NodeInfo(cycles = CYCLES_2, size = SIZE_1)
  48 public final class AllocaNode extends FixedWithNextNode implements LIRLowerable {
  49 
  50     public static final NodeClass<AllocaNode> TYPE = NodeClass.create(AllocaNode.class);
  51     /**
  52      * The number of slots in block.
  53      */
  54     protected final int slots;
  55 
  56     /**
  57      * The indexes of the object pointer slots in the block. Each such object pointer slot must be
  58      * initialized before any safepoint in the method otherwise the garbage collector will see
  59      * garbage values when processing these slots.
  60      */
  61     protected final BitSet objects;
  62 
  63     public AllocaNode(@InjectedNodeParameter WordTypes wordTypes, int slots) {
  64         this(slots, wordTypes.getWordKind(), new BitSet());
  65     }
  66 
  67     public AllocaNode(int slots, JavaKind wordKind, BitSet objects) {
  68         super(TYPE, StampFactory.forKind(wordKind));
  69         this.slots = slots;
  70         this.objects = objects;
  71     }
  72 
  73     @Override
  74     public void generate(NodeLIRBuilderTool gen) {
  75         VirtualStackSlot array = gen.getLIRGeneratorTool().getResult().getFrameMapBuilder().allocateStackSlots(slots, objects, null);
  76         Value result = gen.getLIRGeneratorTool().emitAddress(array);
  77         gen.setResult(this, result);
  78     }
  79 
  80     @NodeIntrinsic
  81     public static native Word alloca(@ConstantNodeParameter int slots);
  82 }