Mercurial > hg > truffle
view graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/UseTrappingNullChecksPhase.java @ 17054:fb8fe09c00a3
Don't remove LoopExitNodes in UseTrappingNullChecksPhase.
author | Roland Schatz <roland.schatz@oracle.com> |
---|---|
date | Fri, 05 Sep 2014 12:27:04 +0200 |
parents | 06c15e88d383 |
children | 45b45f902bed |
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/* * Copyright (c) 2014, 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 java.util.*; import com.oracle.graal.api.meta.*; import com.oracle.graal.debug.*; import com.oracle.graal.graph.*; import com.oracle.graal.nodeinfo.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.StructuredGraph.GuardsStage; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.extended.*; import com.oracle.graal.nodes.util.*; import com.oracle.graal.phases.*; import com.oracle.graal.phases.tiers.*; public class UseTrappingNullChecksPhase extends BasePhase<LowTierContext> { private static final DebugMetric metricTrappingNullCheck = Debug.metric("TrappingNullCheck"); private static final DebugMetric metricTrappingNullCheckUnreached = Debug.metric("TrappingNullCheckUnreached"); private static final DebugMetric metricTrappingNullCheckDynamicDeoptimize = Debug.metric("TrappingNullCheckDynamicDeoptimize"); @Override protected void run(StructuredGraph graph, LowTierContext context) { if (context.getTarget().implicitNullCheckLimit <= 0) { return; } assert graph.getGuardsStage().ordinal() >= GuardsStage.AFTER_FSA.ordinal(); for (DeoptimizeNode deopt : graph.getNodes(DeoptimizeNode.class)) { tryUseTrappingNullCheck(deopt, deopt.predecessor(), deopt.reason(), deopt.getSpeculation()); } for (DynamicDeoptimizeNode deopt : graph.getNodes(DynamicDeoptimizeNode.class)) { tryUseTrappingNullCheck(context.getMetaAccess(), deopt); } } private static void tryUseTrappingNullCheck(MetaAccessProvider metaAccessProvider, DynamicDeoptimizeNode deopt) { Node predecessor = deopt.predecessor(); if (predecessor instanceof MergeNode) { MergeNode merge = (MergeNode) predecessor; // Process each predecessor at the merge, unpacking the reasons and speculations as // needed. ValueNode reason = deopt.getActionAndReason(); ValuePhiNode reasonPhi = null; List<ValueNode> reasons = null; int expectedPhis = 0; if (reason instanceof ValuePhiNode) { reasonPhi = (ValuePhiNode) reason; if (reasonPhi.merge() != merge) { return; } reasons = reasonPhi.values().snapshot(); expectedPhis++; } else if (!reason.isConstant()) { return; } ValueNode speculation = deopt.getSpeculation(); ValuePhiNode speculationPhi = null; List<ValueNode> speculations = null; if (speculation instanceof ValuePhiNode) { speculationPhi = (ValuePhiNode) speculation; if (speculationPhi.merge() != merge) { return; } speculations = speculationPhi.values().snapshot(); expectedPhis++; } if (merge.phis().count() != expectedPhis) { return; } int index = 0; for (AbstractEndNode end : merge.cfgPredecessors().snapshot()) { ValueNode thisReason = reasons != null ? reasons.get(index) : reason; ValueNode thisSpeculation = speculations != null ? speculations.get(index++) : speculation; if (!thisReason.isConstant() || !thisSpeculation.isConstant() || !thisSpeculation.asConstant().equals(Constant.NULL_OBJECT)) { continue; } DeoptimizationReason deoptimizationReason = metaAccessProvider.decodeDeoptReason(thisReason.asConstant()); tryUseTrappingNullCheck(deopt, end.predecessor(), deoptimizationReason, null); } } } private static void tryUseTrappingNullCheck(AbstractDeoptimizeNode deopt, Node predecessor, DeoptimizationReason deoptimizationReason, Constant speculation) { if (deoptimizationReason != DeoptimizationReason.NullCheckException && deoptimizationReason != DeoptimizationReason.UnreachedCode) { return; } if (speculation != null && !speculation.equals(Constant.NULL_OBJECT)) { return; } if (predecessor instanceof MergeNode) { MergeNode merge = (MergeNode) predecessor; if (merge.phis().isEmpty()) { for (AbstractEndNode end : merge.cfgPredecessors().snapshot()) { checkPredecessor(deopt, end.predecessor(), deoptimizationReason); } } } else if (predecessor instanceof BeginNode) { checkPredecessor(deopt, predecessor, deoptimizationReason); } } private static void checkPredecessor(AbstractDeoptimizeNode deopt, Node predecessor, DeoptimizationReason deoptimizationReason) { Node current = predecessor; BeginNode branch = null; while (current instanceof BeginNode) { branch = (BeginNode) current; if (branch.anchored().isNotEmpty()) { // some input of the deopt framestate is anchored to this branch return; } current = current.predecessor(); } if (current instanceof IfNode) { IfNode ifNode = (IfNode) current; if (branch != ifNode.trueSuccessor()) { return; } LogicNode condition = ifNode.condition(); if (condition instanceof IsNullNode) { replaceWithTrappingNullCheck(deopt, ifNode, condition, deoptimizationReason); } } } private static void replaceWithTrappingNullCheck(AbstractDeoptimizeNode deopt, IfNode ifNode, LogicNode condition, DeoptimizationReason deoptimizationReason) { metricTrappingNullCheck.increment(); if (deopt instanceof DynamicDeoptimizeNode) { metricTrappingNullCheckDynamicDeoptimize.increment(); } if (deoptimizationReason == DeoptimizationReason.UnreachedCode) { metricTrappingNullCheckUnreached.increment(); } IsNullNode isNullNode = (IsNullNode) condition; BeginNode nonTrappingContinuation = ifNode.falseSuccessor(); BeginNode trappingContinuation = ifNode.trueSuccessor(); NullCheckNode trappingNullCheck = deopt.graph().add(NullCheckNode.create(isNullNode.getValue())); trappingNullCheck.setStateBefore(deopt.stateBefore()); deopt.graph().replaceSplit(ifNode, trappingNullCheck, nonTrappingContinuation); /* * We now have the pattern NullCheck/BeginNode/... It's possible some node is using the * BeginNode as a guard input, so replace guard users of the Begin with the NullCheck and * then remove the Begin from the graph. */ nonTrappingContinuation.replaceAtUsages(InputType.Guard, trappingNullCheck); if (nonTrappingContinuation.getNodeClass().is(BeginNode.class)) { FixedNode next = nonTrappingContinuation.next(); nonTrappingContinuation.clearSuccessors(); trappingNullCheck.setNext(next); nonTrappingContinuation.safeDelete(); } else { trappingNullCheck.setNext(nonTrappingContinuation); } GraphUtil.killCFG(trappingContinuation); if (isNullNode.usages().isEmpty()) { GraphUtil.killWithUnusedFloatingInputs(isNullNode); } } }