1 /* 2 * Copyright (c) 2013, 2016, 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.nodes.memory; 24 25 import org.graalvm.compiler.core.common.LocationIdentity; 26 import org.graalvm.compiler.core.common.type.Stamp; 27 import org.graalvm.compiler.graph.NodeClass; 28 import org.graalvm.compiler.nodeinfo.NodeInfo; 29 import org.graalvm.compiler.nodes.FrameState; 30 import org.graalvm.compiler.nodes.extended.GuardingNode; 31 import org.graalvm.compiler.nodes.memory.address.AddressNode; 32 33 /** 34 * An {@link FixedAccessNode} that can be converted to a {@link FloatingAccessNode}. 35 */ 36 @NodeInfo 37 public abstract class FloatableAccessNode extends FixedAccessNode { 38 public static final NodeClass<FloatableAccessNode> TYPE = NodeClass.create(FloatableAccessNode.class); 39 40 protected FloatableAccessNode(NodeClass<? extends FloatableAccessNode> c, AddressNode address, LocationIdentity location, Stamp stamp) { 41 super(c, address, location, stamp); 42 } 43 44 protected FloatableAccessNode(NodeClass<? extends FloatableAccessNode> c, AddressNode address, LocationIdentity location, Stamp stamp, GuardingNode guard, BarrierType barrierType) { 45 super(c, address, location, stamp, guard, barrierType, false, null); 46 } 47 48 protected FloatableAccessNode(NodeClass<? extends FloatableAccessNode> c, AddressNode address, LocationIdentity location, Stamp stamp, GuardingNode guard, BarrierType barrierType, 49 boolean nullCheck, FrameState stateBefore) { 50 super(c, address, location, stamp, guard, barrierType, nullCheck, stateBefore); 51 } 52 53 public abstract FloatingAccessNode asFloatingNode(MemoryNode lastLocationAccess); 54 55 protected boolean forceFixed; 56 57 public void setForceFixed(boolean flag) { 58 this.forceFixed = flag; 59 } 60 61 /** 62 * AccessNodes can float only if their location identities are not ANY_LOCATION. Furthermore, in 63 * case G1 is enabled any access (read) to the java.lang.ref.Reference.referent field which has 64 * an attached write barrier with pre-semantics can not also float. 65 */ 66 public boolean canFloat() { 67 return !forceFixed && getLocationIdentity().isSingle() && getBarrierType() == BarrierType.NONE; 68 } 69 }