Mercurial > hg > truffle
view graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/ConvertDeoptimizeToGuardPhase.java @ 19114:b1dbba1f3f03
Restructure CompareNode. Create constant fold utility, store condition as data field.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Wed, 04 Feb 2015 02:28:28 +0100 |
parents | a2cb19764970 |
children | 8ab925a6f724 |
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/* * Copyright (c) 2011, 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.phases.common; import static com.oracle.graal.phases.common.DeadCodeEliminationPhase.Optionality.*; import java.util.*; import com.oracle.graal.api.meta.*; import com.oracle.graal.debug.*; import com.oracle.graal.graph.*; import com.oracle.graal.graph.spi.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.util.*; import com.oracle.graal.phases.*; /** * This phase will find branches which always end with a {@link DeoptimizeNode} and replace their * {@link ControlSplitNode ControlSplitNodes} with {@link FixedGuardNode FixedGuardNodes}. * * This is useful because {@link FixedGuardNode FixedGuardNodes} will be lowered to * {@link GuardNode GuardNodes} which can later be optimized more aggressively than control-flow * constructs. * * This is currently only done for branches that start from a {@link IfNode}. If it encounters a * branch starting at an other kind of {@link ControlSplitNode}, it will only bring the * {@link DeoptimizeNode} as close to the {@link ControlSplitNode} as possible. * */ public class ConvertDeoptimizeToGuardPhase extends Phase { private SimplifierTool simplifierTool = GraphUtil.getDefaultSimplifier(null, null, null, false); private static AbstractBeginNode findBeginNode(FixedNode startNode) { return GraphUtil.predecessorIterable(startNode).filter(AbstractBeginNode.class).first(); } @Override protected void run(final StructuredGraph graph) { assert graph.hasValueProxies() : "ConvertDeoptimizeToGuardPhase always creates proxies"; if (graph.getNodes(DeoptimizeNode.class).isEmpty()) { return; } for (DeoptimizeNode d : graph.getNodes(DeoptimizeNode.class)) { assert d.isAlive(); visitDeoptBegin(AbstractBeginNode.prevBegin(d), d.action(), d.reason(), graph); } for (FixedGuardNode fixedGuard : graph.getNodes(FixedGuardNode.class)) { AbstractBeginNode pred = AbstractBeginNode.prevBegin(fixedGuard); if (pred instanceof AbstractMergeNode) { AbstractMergeNode merge = (AbstractMergeNode) pred; if (fixedGuard.condition() instanceof CompareNode) { CompareNode compare = (CompareNode) fixedGuard.condition(); List<AbstractEndNode> mergePredecessors = merge.cfgPredecessors().snapshot(); Constant[] xs = IfNode.constantValues(compare.getX(), merge, true); if (xs == null) { continue; } Constant[] ys = IfNode.constantValues(compare.getY(), merge, true); if (ys == null) { continue; } for (int i = 0; i < mergePredecessors.size(); ++i) { AbstractEndNode mergePredecessor = mergePredecessors.get(i); if (!mergePredecessor.isAlive()) { break; } if (xs[i] == null) { continue; } if (ys[i] == null) { continue; } if (xs[i] instanceof PrimitiveConstant && ys[i] instanceof PrimitiveConstant && compare.condition().foldCondition(xs[i], ys[i], null, compare.unorderedIsTrue()) == fixedGuard.isNegated()) { visitDeoptBegin(AbstractBeginNode.prevBegin(mergePredecessor), fixedGuard.getAction(), fixedGuard.getReason(), graph); } } } } } new DeadCodeEliminationPhase(Optional).apply(graph); } private void visitDeoptBegin(AbstractBeginNode deoptBegin, DeoptimizationAction deoptAction, DeoptimizationReason deoptReason, StructuredGraph graph) { if (deoptBegin instanceof AbstractMergeNode) { AbstractMergeNode mergeNode = (AbstractMergeNode) deoptBegin; Debug.log("Visiting %s", mergeNode); FixedNode next = mergeNode.next(); while (mergeNode.isAlive()) { AbstractEndNode end = mergeNode.forwardEnds().first(); AbstractBeginNode newBeginNode = findBeginNode(end); visitDeoptBegin(newBeginNode, deoptAction, deoptReason, graph); } assert next.isAlive(); AbstractBeginNode newBeginNode = findBeginNode(next); visitDeoptBegin(newBeginNode, deoptAction, deoptReason, graph); return; } else if (deoptBegin.predecessor() instanceof IfNode) { IfNode ifNode = (IfNode) deoptBegin.predecessor(); AbstractBeginNode otherBegin = ifNode.trueSuccessor(); LogicNode conditionNode = ifNode.condition(); FixedGuardNode guard = graph.add(new FixedGuardNode(conditionNode, deoptReason, deoptAction, deoptBegin == ifNode.trueSuccessor())); FixedWithNextNode pred = (FixedWithNextNode) ifNode.predecessor(); AbstractBeginNode survivingSuccessor; if (deoptBegin == ifNode.trueSuccessor()) { survivingSuccessor = ifNode.falseSuccessor(); } else { survivingSuccessor = ifNode.trueSuccessor(); } graph.removeSplitPropagate(ifNode, survivingSuccessor); ProxyNode proxyGuard = null; for (Node n : survivingSuccessor.usages().snapshot()) { if (n instanceof GuardNode || n instanceof ProxyNode) { // Keep wired to the begin node. } else { // Rewire to the fixed guard. if (survivingSuccessor instanceof LoopExitNode) { if (proxyGuard == null) { proxyGuard = ProxyNode.forGuard(guard, survivingSuccessor, graph); } n.replaceFirstInput(survivingSuccessor, proxyGuard); } else { n.replaceFirstInput(survivingSuccessor, guard); } } } Debug.log("Converting deopt on %-5s branch of %s to guard for remaining branch %s.", deoptBegin == ifNode.trueSuccessor() ? "true" : "false", ifNode, otherBegin); FixedNode next = pred.next(); pred.setNext(guard); guard.setNext(next); survivingSuccessor.simplify(simplifierTool); return; } // We could not convert the control split - at least cut off control flow after the split. FixedWithNextNode deoptPred = deoptBegin; FixedNode next = deoptPred.next(); if (!(next instanceof DeoptimizeNode)) { DeoptimizeNode newDeoptNode = graph.add(new DeoptimizeNode(deoptAction, deoptReason)); deoptPred.setNext(newDeoptNode); assert deoptPred == newDeoptNode.predecessor(); GraphUtil.killCFG(next); } } }