| /* |
| * Copyright (c) 2012, 2016, 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 org.graalvm.compiler.loop; |
| |
| import static org.graalvm.compiler.core.common.GraalOptions.LoopMaxUnswitch; |
| import static org.graalvm.compiler.core.common.GraalOptions.MaximumDesiredSize; |
| import static org.graalvm.compiler.core.common.GraalOptions.MinimumPeelProbability; |
| |
| import java.util.List; |
| |
| import org.graalvm.compiler.debug.Debug; |
| import org.graalvm.compiler.debug.DebugCounter; |
| import org.graalvm.compiler.graph.Node; |
| import org.graalvm.compiler.graph.NodeBitMap; |
| import org.graalvm.compiler.nodes.AbstractBeginNode; |
| import org.graalvm.compiler.nodes.ControlSplitNode; |
| import org.graalvm.compiler.nodes.DeoptimizeNode; |
| import org.graalvm.compiler.nodes.FixedNode; |
| import org.graalvm.compiler.nodes.FixedWithNextNode; |
| import org.graalvm.compiler.nodes.LoopBeginNode; |
| import org.graalvm.compiler.nodes.MergeNode; |
| import org.graalvm.compiler.nodes.VirtualState; |
| import org.graalvm.compiler.nodes.VirtualState.VirtualClosure; |
| import org.graalvm.compiler.nodes.cfg.Block; |
| import org.graalvm.compiler.nodes.cfg.ControlFlowGraph; |
| import org.graalvm.compiler.nodes.java.TypeSwitchNode; |
| import org.graalvm.compiler.options.Option; |
| import org.graalvm.compiler.options.OptionType; |
| import org.graalvm.compiler.options.OptionValue; |
| |
| import jdk.vm.ci.meta.MetaAccessProvider; |
| |
| public class DefaultLoopPolicies implements LoopPolicies { |
| @Option(help = "", type = OptionType.Expert) public static final OptionValue<Integer> LoopUnswitchMaxIncrease = new OptionValue<>(500); |
| @Option(help = "", type = OptionType.Expert) public static final OptionValue<Integer> LoopUnswitchTrivial = new OptionValue<>(10); |
| @Option(help = "", type = OptionType.Expert) public static final OptionValue<Double> LoopUnswitchFrequencyBoost = new OptionValue<>(10.0); |
| |
| @Option(help = "", type = OptionType.Expert) public static final OptionValue<Integer> FullUnrollMaxNodes = new OptionValue<>(300); |
| @Option(help = "", type = OptionType.Expert) public static final OptionValue<Integer> FullUnrollMaxIterations = new OptionValue<>(600); |
| @Option(help = "", type = OptionType.Expert) public static final OptionValue<Integer> ExactFullUnrollMaxNodes = new OptionValue<>(1200); |
| |
| @Override |
| public boolean shouldPeel(LoopEx loop, ControlFlowGraph cfg, MetaAccessProvider metaAccess) { |
| LoopBeginNode loopBegin = loop.loopBegin(); |
| double entryProbability = cfg.blockFor(loopBegin.forwardEnd()).probability(); |
| if (entryProbability > MinimumPeelProbability.getValue() && loop.size() + loopBegin.graph().getNodeCount() < MaximumDesiredSize.getValue()) { |
| // check whether we're allowed to peel this loop |
| return loop.canDuplicateLoop(); |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public boolean shouldFullUnroll(LoopEx loop) { |
| if (!loop.isCounted() || !loop.counted().isConstantMaxTripCount()) { |
| return false; |
| } |
| CountedLoopInfo counted = loop.counted(); |
| long maxTrips = counted.constantMaxTripCount(); |
| int maxNodes = (counted.isExactTripCount() && counted.isConstantExactTripCount()) ? ExactFullUnrollMaxNodes.getValue() : FullUnrollMaxNodes.getValue(); |
| maxNodes = Math.min(maxNodes, Math.max(0, MaximumDesiredSize.getValue() - loop.loopBegin().graph().getNodeCount())); |
| int size = Math.max(1, loop.size() - 1 - loop.loopBegin().phis().count()); |
| if (maxTrips <= FullUnrollMaxIterations.getValue() && size * (maxTrips - 1) <= maxNodes) { |
| // check whether we're allowed to unroll this loop |
| return loop.canDuplicateLoop(); |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public boolean shouldTryUnswitch(LoopEx loop) { |
| LoopBeginNode loopBegin = loop.loopBegin(); |
| double loopFrequency = loopBegin.loopFrequency(); |
| if (loopFrequency <= 1.0) { |
| return false; |
| } |
| return loopBegin.unswitches() <= LoopMaxUnswitch.getValue(); |
| } |
| |
| private static final class CountingClosure implements VirtualClosure { |
| int count; |
| |
| @Override |
| public void apply(VirtualState node) { |
| count++; |
| } |
| } |
| |
| private static class IsolatedInitialization { |
| static final DebugCounter UNSWITCH_SPLIT_WITH_PHIS = Debug.counter("UnswitchSplitWithPhis"); |
| } |
| |
| @Override |
| public boolean shouldUnswitch(LoopEx loop, List<ControlSplitNode> controlSplits) { |
| int phis = 0; |
| NodeBitMap branchNodes = loop.loopBegin().graph().createNodeBitMap(); |
| for (ControlSplitNode controlSplit : controlSplits) { |
| for (Node successor : controlSplit.successors()) { |
| AbstractBeginNode branch = (AbstractBeginNode) successor; |
| // this may count twice because of fall-through in switches |
| loop.nodesInLoopBranch(branchNodes, branch); |
| } |
| Block postDomBlock = loop.loopsData().getCFG().blockFor(controlSplit).getPostdominator(); |
| if (postDomBlock != null) { |
| IsolatedInitialization.UNSWITCH_SPLIT_WITH_PHIS.increment(); |
| phis += ((MergeNode) postDomBlock.getBeginNode()).phis().count(); |
| } |
| } |
| int inBranchTotal = branchNodes.count(); |
| |
| CountingClosure stateNodesCount = new CountingClosure(); |
| double loopFrequency = loop.loopBegin().loopFrequency(); |
| int maxDiff = LoopUnswitchTrivial.getValue() + (int) (LoopUnswitchFrequencyBoost.getValue() * (loopFrequency - 1.0 + phis)); |
| |
| maxDiff = Math.min(maxDiff, LoopUnswitchMaxIncrease.getValue()); |
| int remainingGraphSpace = MaximumDesiredSize.getValue() - loop.loopBegin().graph().getNodeCount(); |
| maxDiff = Math.min(maxDiff, remainingGraphSpace); |
| |
| loop.loopBegin().stateAfter().applyToVirtual(stateNodesCount); |
| int loopTotal = loop.size() - loop.loopBegin().phis().count() - stateNodesCount.count - 1; |
| int actualDiff = (loopTotal - inBranchTotal); |
| ControlSplitNode firstSplit = controlSplits.get(0); |
| if (firstSplit instanceof TypeSwitchNode) { |
| int copies = firstSplit.successors().count() - 1; |
| for (Node succ : firstSplit.successors()) { |
| FixedNode current = (FixedNode) succ; |
| while (current instanceof FixedWithNextNode) { |
| current = ((FixedWithNextNode) current).next(); |
| } |
| if (current instanceof DeoptimizeNode) { |
| copies--; |
| } |
| } |
| actualDiff = actualDiff * copies; |
| } |
| |
| Debug.log("shouldUnswitch(%s, %s) : delta=%d (%.2f%% inside of branches), max=%d, f=%.2f, phis=%d -> %b", loop, controlSplits, actualDiff, (double) (inBranchTotal) / loopTotal * 100, maxDiff, |
| loopFrequency, phis, actualDiff <= maxDiff); |
| if (actualDiff <= maxDiff) { |
| // check whether we're allowed to unswitch this loop |
| return loop.canDuplicateLoop(); |
| } else { |
| return false; |
| } |
| } |
| |
| } |
