Mercurial > hg > graal-jvmci-8
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/LoadFieldNode.java @ 18937:ff232ff8d028
Add utility Node#hasNoUsages.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Fri, 23 Jan 2015 11:52:36 +0100 |
parents | f57d86eb036f |
children | ec0733b5a90a |
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/* * Copyright (c) 2009, 2014, 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 static com.oracle.graal.graph.iterators.NodePredicates.*; import com.oracle.graal.api.meta.*; import com.oracle.graal.compiler.common.type.*; import com.oracle.graal.graph.spi.*; import com.oracle.graal.nodeinfo.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.nodes.type.*; import com.oracle.graal.nodes.virtual.*; /** * The {@code LoadFieldNode} represents a read of a static or instance field. */ @NodeInfo(nameTemplate = "LoadField#{p#field/s}") public class LoadFieldNode extends AccessFieldNode implements Canonicalizable.Unary<ValueNode>, VirtualizableRoot, UncheckedInterfaceProvider { public LoadFieldNode(ValueNode object, ResolvedJavaField field) { super(createStamp(field), object, field); } public ValueNode getValue() { return object(); } private static Stamp createStamp(ResolvedJavaField field) { Kind kind = field.getKind(); if (kind == Kind.Object && field.getType() instanceof ResolvedJavaType) { return StampFactory.declared((ResolvedJavaType) field.getType()); } else { return StampFactory.forKind(kind); } } public ValueNode canonical(CanonicalizerTool tool, ValueNode forObject) { if (hasNoUsages() && !isVolatile() && (isStatic() || StampTool.isPointerNonNull(forObject.stamp()))) { return null; } MetaAccessProvider metaAccess = tool.getMetaAccess(); ConstantReflectionProvider constantReflection = tool.getConstantReflection(); if (tool.canonicalizeReads() && metaAccess != null) { ConstantNode constant = asConstant(metaAccess, constantReflection, forObject); if (constant != null) { return constant; } PhiNode phi = asPhi(metaAccess, constantReflection, forObject); if (phi != null) { return phi; } } if (!isStatic() && forObject.isNullConstant()) { return new DeoptimizeNode(DeoptimizationAction.None, DeoptimizationReason.NullCheckException); } return this; } /** * Gets a constant value for this load if possible. */ public ConstantNode asConstant(MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection, ValueNode forObject) { JavaConstant constant = null; if (isStatic()) { constant = constantReflection.readConstantFieldValue(field(), null); } else if (forObject.isConstant() && !forObject.isNullConstant()) { constant = constantReflection.readConstantFieldValue(field(), forObject.asJavaConstant()); } if (constant != null) { return ConstantNode.forConstant(constant, metaAccess); } return null; } private PhiNode asPhi(MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection, ValueNode forObject) { if (!isStatic() && field.isFinal() && forObject instanceof ValuePhiNode && ((ValuePhiNode) forObject).values().filter(isNotA(ConstantNode.class)).isEmpty()) { PhiNode phi = (PhiNode) forObject; JavaConstant[] constants = new JavaConstant[phi.valueCount()]; for (int i = 0; i < phi.valueCount(); i++) { JavaConstant constantValue = constantReflection.readConstantFieldValue(field(), phi.valueAt(i).asJavaConstant()); if (constantValue == null) { return null; } constants[i] = constantValue; } ConstantNode[] constantNodes = new ConstantNode[phi.valueCount()]; for (int i = 0; i < phi.valueCount(); i++) { constantNodes[i] = ConstantNode.forConstant(constants[i], metaAccess); } return new ValuePhiNode(stamp(), phi.merge(), constantNodes); } return null; } @Override public void virtualize(VirtualizerTool tool) { State state = tool.getObjectState(object()); if (state != null && state.getState() == EscapeState.Virtual) { int fieldIndex = ((VirtualInstanceNode) state.getVirtualObject()).fieldIndex(field()); if (fieldIndex != -1) { tool.replaceWith(state.getEntry(fieldIndex)); } } } public Stamp uncheckedStamp() { return UncheckedInterfaceProvider.uncheckedOrNull(field().getType(), stamp()); } }