Mercurial > hg > truffle
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ReadNode.java @ 11397:956bf8c5bd8f
Fix for ReadNode.push which could cause some reads to float before the necessary checkcast.
This would cause loading non-oops as if they were oops in some rare cases.
author | Gilles Duboscq <duboscq@ssw.jku.at> |
---|---|
date | Thu, 22 Aug 2013 20:04:51 +0200 |
parents | ef6915cf1e59 |
children | 95cbf029018c |
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/* * Copyright (c) 2011, 2012, 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.extended; import com.oracle.graal.api.meta.*; import com.oracle.graal.graph.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.nodes.type.*; import com.oracle.graal.nodes.virtual.*; /** * Reads an {@linkplain AccessNode accessed} value. */ public final class ReadNode extends FloatableAccessNode implements Node.IterableNodeType, LIRLowerable, Canonicalizable, PiPushable, Virtualizable { public ReadNode(ValueNode object, ValueNode location, Stamp stamp, BarrierType barrierType, boolean compressible) { super(object, location, stamp, barrierType, compressible); } public ReadNode(ValueNode object, ValueNode location, Stamp stamp, GuardingNode guard, BarrierType barrierType, boolean compressible) { super(object, location, stamp, guard, barrierType, compressible); } public ReadNode(ValueNode object, int displacement, LocationIdentity locationIdentity, Kind kind) { super(object, ConstantLocationNode.create(locationIdentity, kind, displacement, object.graph()), StampFactory.forKind(kind)); } private ReadNode(ValueNode object, ValueNode location, ValueNode guard) { /* * Used by node intrinsics. Since the initial value for location is a parameter, i.e., a * LocalNode, the constructor cannot use the declared type LocationNode. */ super(object, location, StampFactory.forNodeIntrinsic(), (GuardingNode) guard, BarrierType.NONE, false); } @Override public void generate(LIRGeneratorTool gen) { Value address = location().generateAddress(gen, gen.operand(object())); gen.setResult(this, gen.emitLoad(location().getValueKind(), address, this)); } @Override public ValueNode canonical(CanonicalizerTool tool) { return canonicalizeRead(this, location(), object(), tool, isCompressible()); } @Override public FloatingAccessNode asFloatingNode(ValueNode lastLocationAccess) { return graph().unique(new FloatingReadNode(object(), location(), lastLocationAccess, stamp(), getGuard(), getBarrierType(), isCompressible())); } public static ValueNode canonicalizeRead(ValueNode read, LocationNode location, ValueNode object, CanonicalizerTool tool, boolean compressible) { MetaAccessProvider runtime = tool.runtime(); if (read.usages().count() == 0) { // Read without usages can be savely removed. return null; } if (tool.canonicalizeReads() && runtime != null && object != null && object.isConstant()) { if (location.getLocationIdentity() == LocationIdentity.FINAL_LOCATION && location instanceof ConstantLocationNode) { long displacement = ((ConstantLocationNode) location).getDisplacement(); Kind kind = location.getValueKind(); if (object.kind() == Kind.Object) { Object base = object.asConstant().asObject(); if (base != null) { Constant constant = tool.runtime().readUnsafeConstant(kind, base, displacement, compressible); if (constant != null) { return ConstantNode.forConstant(constant, runtime, read.graph()); } } } else if (object.kind() == Kind.Long || object.kind().getStackKind() == Kind.Int) { long base = object.asConstant().asLong(); if (base != 0L) { Constant constant = tool.runtime().readUnsafeConstant(kind, null, base + displacement, compressible); if (constant != null) { return ConstantNode.forConstant(constant, runtime, read.graph()); } } } } } return read; } @Override public boolean push(PiNode parent) { if (location() instanceof ConstantLocationNode) { long displacement = ((ConstantLocationNode) location()).getDisplacement(); if (parent.stamp() instanceof ObjectStamp) { ObjectStamp piStamp = (ObjectStamp) parent.stamp(); ResolvedJavaType receiverType = piStamp.type(); if (receiverType != null) { ResolvedJavaField field = receiverType.findInstanceFieldWithOffset(displacement); if (field != null && parent.object().stamp() instanceof ObjectStamp) { ResolvedJavaType declaringClass = field.getDeclaringClass(); ObjectStamp piValueStamp = (ObjectStamp) parent.object().stamp(); ResolvedJavaType piValueType = ObjectStamp.typeOrNull(piValueStamp); if (piValueType != null && declaringClass.isAssignableFrom(piValueType) && declaringClass != receiverType) { if (piStamp.nonNull() == piValueStamp.nonNull() && piStamp.alwaysNull() == piValueStamp.alwaysNull()) { replaceFirstInput(parent, parent.object()); return true; } } } } } } return false; } @Override public void virtualize(VirtualizerTool tool) { if (location() instanceof ConstantLocationNode) { ConstantLocationNode constantLocation = (ConstantLocationNode) location(); State state = tool.getObjectState(object()); if (state != null && state.getState() == EscapeState.Virtual) { VirtualObjectNode virtual = state.getVirtualObject(); int entryIndex = virtual.entryIndexForOffset(constantLocation.getDisplacement()); if (entryIndex != -1 && virtual.entryKind(entryIndex) == constantLocation.getValueKind()) { tool.replaceWith(state.getEntry(entryIndex)); } } } } }