Mercurial > hg > graal-compiler
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/UnsafeCastNode.java @ 22349:681c04ce9db2
PEA refactoring: simplify VirtualizerTool, arrays instead of HashMaps, route all modifications through BlockState, copy-on-write in BlockState
author | Lukas Stadler <lukas.stadler@oracle.com> |
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date | Fri, 24 Jul 2015 16:20:56 +0200 |
parents | 0e095e2c24e2 |
children | b611fa9fef24 |
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/* * Copyright (c) 2009, 2015, 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 jdk.internal.jvmci.meta.*; import com.oracle.graal.compiler.common.type.*; import com.oracle.graal.graph.*; 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 UnsafeCastNode} produces the same value as its input, but with a different type. It * allows unsafe casts "sideways" in the type hierarchy. It does not allow to "drop" type * information, i.e., an unsafe cast is removed if the input object has a more precise or equal type * than the type this nodes casts to. */ @NodeInfo public final class UnsafeCastNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, GuardingNode, IterableNodeType, Canonicalizable, ValueProxy { public static final NodeClass<UnsafeCastNode> TYPE = NodeClass.create(UnsafeCastNode.class); @Input ValueNode object; public UnsafeCastNode(ValueNode object, Stamp stamp) { super(TYPE, stamp); this.object = object; } public UnsafeCastNode(ValueNode object, Stamp stamp, ValueNode anchor) { super(TYPE, stamp, (GuardingNode) anchor); this.object = object; } public UnsafeCastNode(ValueNode object, ResolvedJavaType toType, boolean exactType, boolean nonNull) { this(object, toType.getKind() == Kind.Object ? StampFactory.object(toType, exactType, nonNull || StampTool.isPointerNonNull(object.stamp()), true) : StampFactory.forKind(toType.getKind())); } @Override public ValueNode getOriginalNode() { return object; } @Override public Node canonical(CanonicalizerTool tool) { assert getKind() == Kind.Object && object.getKind() == Kind.Object; ObjectStamp my = (ObjectStamp) stamp(); ObjectStamp other = (ObjectStamp) object.stamp(); if (my.type() == null || other.type() == null) { return this; } if (my.isExactType() && !other.isExactType()) { return this; } if (my.nonNull() && !other.nonNull()) { return this; } if (!my.type().isAssignableFrom(other.type())) { return this; } /* * The unsafe cast does not add any new type information, so it can be removed. Note that * this means that the unsafe cast cannot be used to "drop" type information (in which case * it must not be canonicalized in any case). */ return object; } @Override public void virtualize(VirtualizerTool tool) { ValueNode alias = tool.getAlias(object); if (alias instanceof VirtualObjectNode) { VirtualObjectNode virtual = (VirtualObjectNode) alias; if (StampTool.typeOrNull(this) != null && StampTool.typeOrNull(this).isAssignableFrom(virtual.type())) { tool.replaceWithVirtual(virtual); } } } @Override public void generate(NodeLIRBuilderTool generator) { assert getKind() == Kind.Object && object.getKind() == Kind.Object; /* * The LIR only cares about the kind of an operand, not the actual type of an object. So we * do not have to introduce a new operand. */ generator.setResult(this, generator.operand(object)); } }