Mercurial > hg > graal-compiler
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ValueAnchorNode.java @ 5447:78a6f682326f
Canonicalize away ValueAnchors that only anchor a begin node
author | Gilles Duboscq <duboscq@ssw.jku.at> |
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date | Fri, 25 May 2012 13:21:43 +0200 |
parents | 1d63466ba795 |
children | 56f4afcf71f7 |
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/* * Copyright (c) 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.graal.nodes.extended; import static com.oracle.graal.graph.iterators.NodePredicates.*; import com.oracle.graal.graph.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.nodes.type.*; import com.oracle.max.cri.ci.*; /** * The ValueAnchor instruction keeps non-CFG (floating) nodes above a certain point in the graph. */ public final class ValueAnchorNode extends FixedWithNextNode implements Canonicalizable, LIRLowerable, Node.IterableNodeType { public ValueAnchorNode(ValueNode... values) { super(StampFactory.illegal(), values); } @Override public void generate(LIRGeneratorTool gen) { // Nothing to emit, since this node is used for structural purposes only. } public void addAnchoredNode(Node value) { if (!this.dependencies().contains(value)) { this.dependencies().add(value); } } @Override public ValueNode canonical(CanonicalizerTool tool) { if (this.predecessor() instanceof ValueAnchorNode) { // transfer values and remove ValueAnchorNode previousAnchor = (ValueAnchorNode) this.predecessor(); for (Node node : dependencies().nonNull().distinct()) { previousAnchor.addAnchoredNode(node); } return null; } for (Node node : dependencies().nonNull().and(isNotA(BeginNode.class))) { if (node instanceof ConstantNode) { continue; } if (node instanceof IntegerDivNode || node instanceof IntegerRemNode) { ArithmeticNode arithmeticNode = (ArithmeticNode) node; if (arithmeticNode.y().isConstant()) { CiConstant constant = arithmeticNode.y().asConstant(); assert constant.kind == arithmeticNode.kind() : constant.kind + " != " + arithmeticNode.kind(); if (constant.asLong() != 0) { continue; } } } return this; // still necessary } return null; // no node which require an anchor found } }