Mercurial > hg > graal-compiler
view graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/UseTrappingNullChecksPhase.java @ 19450:fb20fbfd6a85
Add a probability-based cut-off to the inlining policy.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
---|---|
date | Tue, 17 Feb 2015 16:31:39 +0100 |
parents | 61d3cb8e1280 |
children | b1530a6cce8c |
line wrap: on
line source
/* * 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.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().areFrameStatesAtDeopts(); for (DeoptimizeNode deopt : graph.getNodes(DeoptimizeNode.TYPE)) { tryUseTrappingNullCheck(deopt, deopt.predecessor(), deopt.reason(), deopt.getSpeculation()); } for (DynamicDeoptimizeNode deopt : graph.getNodes(DynamicDeoptimizeNode.TYPE)) { tryUseTrappingNullCheck(context.getMetaAccess(), deopt); } } private static void tryUseTrappingNullCheck(MetaAccessProvider metaAccessProvider, DynamicDeoptimizeNode deopt) { Node predecessor = deopt.predecessor(); if (predecessor instanceof AbstractMergeNode) { AbstractMergeNode merge = (AbstractMergeNode) 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(JavaConstant.NULL_POINTER)) { continue; } DeoptimizationReason deoptimizationReason = metaAccessProvider.decodeDeoptReason(thisReason.asJavaConstant()); tryUseTrappingNullCheck(deopt, end.predecessor(), deoptimizationReason, null); } } } private static void tryUseTrappingNullCheck(AbstractDeoptimizeNode deopt, Node predecessor, DeoptimizationReason deoptimizationReason, JavaConstant speculation) { if (deoptimizationReason != DeoptimizationReason.NullCheckException && deoptimizationReason != DeoptimizationReason.UnreachedCode) { return; } if (speculation != null && !speculation.equals(JavaConstant.NULL_POINTER)) { return; } if (predecessor instanceof AbstractMergeNode) { AbstractMergeNode merge = (AbstractMergeNode) predecessor; if (merge.phis().isEmpty()) { for (AbstractEndNode end : merge.cfgPredecessors().snapshot()) { checkPredecessor(deopt, end.predecessor(), deoptimizationReason); } } } else if (predecessor instanceof AbstractBeginNode) { checkPredecessor(deopt, predecessor, deoptimizationReason); } } private static void checkPredecessor(AbstractDeoptimizeNode deopt, Node predecessor, DeoptimizationReason deoptimizationReason) { Node current = predecessor; AbstractBeginNode branch = null; while (current instanceof AbstractBeginNode) { branch = (AbstractBeginNode) 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; AbstractBeginNode nonTrappingContinuation = ifNode.falseSuccessor(); AbstractBeginNode trappingContinuation = ifNode.trueSuccessor(); NullCheckNode trappingNullCheck = deopt.graph().add(new NullCheckNode(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 instanceof BeginNode) { FixedNode next = nonTrappingContinuation.next(); nonTrappingContinuation.clearSuccessors(); trappingNullCheck.setNext(next); nonTrappingContinuation.safeDelete(); } else { trappingNullCheck.setNext(nonTrappingContinuation); } GraphUtil.killCFG(trappingContinuation); if (isNullNode.hasNoUsages()) { GraphUtil.killWithUnusedFloatingInputs(isNullNode); } } }