Mercurial > hg > graal-jvmci-8
view graal/com.oracle.max.graal.nodes/src/com/oracle/max/graal/nodes/calc/NullCheckNode.java @ 4309:4a609a685fa4
changes to Node structures:
* add more uses of higher-level graph manipulation methods
* CanonicalierPhase cleanup
* introduce FloatingReadNode, make ReadNode an ordinary fixed nodeToBlock
* let Canonicalizable.canonical return ValueNode (instead of Node)
author | Lukas Stadler <lukas.stadler@jku.at> |
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date | Tue, 17 Jan 2012 19:45:39 +0100 |
parents | aaac4894175c |
children |
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/* * Copyright (c) 2009, 2011, 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.max.graal.nodes.calc; import com.oracle.max.cri.ci.*; import com.oracle.max.graal.nodes.*; import com.oracle.max.graal.nodes.spi.*; import com.oracle.max.graal.nodes.type.*; public final class NullCheckNode extends BooleanNode implements Canonicalizable, LIRLowerable { @Input private ValueNode object; @Data public final boolean expectedNull; public ValueNode object() { return object; } /** * Constructs a new NullCheck instruction. * * @param object the instruction producing the object to check against null * @param expectedNull True when this node checks that the value is null, false when this node checks for non-null */ public NullCheckNode(ValueNode object, boolean expectedNull) { super(StampFactory.illegal()); assert object.kind() == CiKind.Object : object.kind(); this.object = object; this.expectedNull = expectedNull; } @Override public void generate(LIRGeneratorTool gen) { // Nothing to do. } @Override public boolean verify() { assertTrue(object().kind().isObject(), "null check input must be an object"); return super.verify(); } @Override public ValueNode canonical(CanonicalizerTool tool) { CiConstant constant = object().asConstant(); if (constant != null) { assert constant.kind == CiKind.Object; return ConstantNode.forBoolean(constant.isNull() == expectedNull, graph()); } if (object.stamp().nonNull()) { return ConstantNode.forBoolean(!expectedNull, graph()); } return this; } @Override public BooleanNode negate() { return graph().unique(new NullCheckNode(object(), !expectedNull)); } }