1 /*
   2  * Copyright (c) 2012, 2018, 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 
  24 
  25 package org.graalvm.compiler.hotspot.nodes;
  26 
  27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
  28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  29 
  30 import java.util.BitSet;
  31 
  32 import org.graalvm.compiler.core.common.type.StampFactory;
  33 import org.graalvm.compiler.graph.NodeClass;
  34 import org.graalvm.compiler.lir.VirtualStackSlot;
  35 import org.graalvm.compiler.nodeinfo.NodeInfo;
  36 import org.graalvm.compiler.nodes.FixedWithNextNode;
  37 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  38 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  39 import org.graalvm.compiler.word.Word;
  40 import org.graalvm.compiler.word.WordTypes;
  41 
  42 import jdk.vm.ci.meta.JavaKind;
  43 import jdk.vm.ci.meta.Value;
  44 
  45 /**
  46  * Reserves a block of memory in the stack frame of a method. The block is reserved in the frame for
  47  * the entire execution of the associated method.
  48  */
  49 @NodeInfo(cycles = CYCLES_2, size = SIZE_1)
  50 public final class AllocaNode extends FixedWithNextNode implements LIRLowerable {
  51 
  52     public static final NodeClass<AllocaNode> TYPE = NodeClass.create(AllocaNode.class);
  53     /**
  54      * The number of slots in block.
  55      */
  56     protected final int slots;
  57 
  58     /**
  59      * The indexes of the object pointer slots in the block. Each such object pointer slot must be
  60      * initialized before any safepoint in the method otherwise the garbage collector will see
  61      * garbage values when processing these slots.
  62      */
  63     protected final BitSet objects;
  64 
  65     public AllocaNode(@InjectedNodeParameter WordTypes wordTypes, int slots) {
  66         this(slots, wordTypes.getWordKind(), new BitSet());
  67     }
  68 
  69     public AllocaNode(int slots, JavaKind wordKind, BitSet objects) {
  70         super(TYPE, StampFactory.forKind(wordKind));
  71         this.slots = slots;
  72         this.objects = objects;
  73     }
  74 
  75     @Override
  76     public void generate(NodeLIRBuilderTool gen) {
  77         VirtualStackSlot array = gen.getLIRGeneratorTool().getResult().getFrameMapBuilder().allocateStackSlots(slots, objects, null);
  78         Value result = gen.getLIRGeneratorTool().emitAddress(array);
  79         gen.setResult(this, result);
  80     }
  81 
  82     @NodeIntrinsic
  83     public static native Word alloca(@ConstantNodeParameter int slots);
  84 }