| /* |
| * 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.core.common.util.UnsignedLong; |
| import org.graalvm.compiler.debug.CounterKey; |
| import org.graalvm.compiler.debug.DebugContext; |
| 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.InvokeNode; |
| import org.graalvm.compiler.nodes.LoopBeginNode; |
| import org.graalvm.compiler.nodes.MergeNode; |
| import org.graalvm.compiler.nodes.StructuredGraph; |
| 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.debug.ControlFlowAnchorNode; |
| import org.graalvm.compiler.nodes.java.TypeSwitchNode; |
| import org.graalvm.compiler.options.Option; |
| import org.graalvm.compiler.options.OptionKey; |
| import org.graalvm.compiler.options.OptionType; |
| import org.graalvm.compiler.options.OptionValues; |
| |
| import jdk.vm.ci.meta.MetaAccessProvider; |
| |
| public class DefaultLoopPolicies implements LoopPolicies { |
| |
| public static class Options { |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Integer> LoopUnswitchMaxIncrease = new OptionKey<>(500); |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Integer> LoopUnswitchTrivial = new OptionKey<>(10); |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Double> LoopUnswitchFrequencyBoost = new OptionKey<>(10.0); |
| |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Integer> FullUnrollMaxNodes = new OptionKey<>(300); |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Integer> FullUnrollMaxIterations = new OptionKey<>(600); |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Integer> ExactFullUnrollMaxNodes = new OptionKey<>(1200); |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Integer> ExactPartialUnrollMaxNodes = new OptionKey<>(200); |
| |
| @Option(help = "", type = OptionType.Expert) public static final OptionKey<Integer> UnrollMaxIterations = new OptionKey<>(16); |
| } |
| |
| @Override |
| public boolean shouldPeel(LoopEx loop, ControlFlowGraph cfg, MetaAccessProvider metaAccess) { |
| LoopBeginNode loopBegin = loop.loopBegin(); |
| double entryProbability = cfg.blockFor(loopBegin.forwardEnd()).probability(); |
| OptionValues options = cfg.graph.getOptions(); |
| if (entryProbability > MinimumPeelProbability.getValue(options) && loop.size() + loopBegin.graph().getNodeCount() < MaximumDesiredSize.getValue(options)) { |
| // 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; |
| } |
| OptionValues options = loop.entryPoint().getOptions(); |
| CountedLoopInfo counted = loop.counted(); |
| UnsignedLong maxTrips = counted.constantMaxTripCount(); |
| if (maxTrips.equals(0)) { |
| return loop.canDuplicateLoop(); |
| } |
| int maxNodes = (counted.isExactTripCount() && counted.isConstantExactTripCount()) ? Options.ExactFullUnrollMaxNodes.getValue(options) : Options.FullUnrollMaxNodes.getValue(options); |
| maxNodes = Math.min(maxNodes, Math.max(0, MaximumDesiredSize.getValue(options) - loop.loopBegin().graph().getNodeCount())); |
| int size = Math.max(1, loop.size() - 1 - loop.loopBegin().phis().count()); |
| /* @formatter:off |
| * The check below should not throw ArithmeticException because: |
| * maxTrips is guaranteed to be >= 1 by the check above |
| * - maxTrips * size can not overfow because: |
| * - maxTrips <= FullUnrollMaxIterations <= Integer.MAX_VALUE |
| * - 1 <= size <= Integer.MAX_VALUE |
| * @formatter:on |
| */ |
| if (maxTrips.isLessOrEqualTo(Options.FullUnrollMaxIterations.getValue(options)) && maxTrips.minus(1).times(size).isLessOrEqualTo(maxNodes)) { |
| // check whether we're allowed to unroll this loop |
| return loop.canDuplicateLoop(); |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public boolean shouldPartiallyUnroll(LoopEx loop) { |
| LoopBeginNode loopBegin = loop.loopBegin(); |
| if (!loop.isCounted()) { |
| loopBegin.getDebug().log(DebugContext.VERBOSE_LEVEL, "shouldPartiallyUnroll %s isn't counted", loopBegin); |
| return false; |
| } |
| OptionValues options = loop.entryPoint().getOptions(); |
| int maxNodes = Options.ExactPartialUnrollMaxNodes.getValue(options); |
| maxNodes = Math.min(maxNodes, Math.max(0, MaximumDesiredSize.getValue(options) - loop.loopBegin().graph().getNodeCount())); |
| int size = Math.max(1, loop.size() - 1 - loop.loopBegin().phis().count()); |
| int unrollFactor = loopBegin.getUnrollFactor(); |
| if (unrollFactor == 1) { |
| double loopFrequency = loopBegin.loopFrequency(); |
| if (loopBegin.isSimpleLoop() && loopFrequency < 5.0) { |
| loopBegin.getDebug().log(DebugContext.VERBOSE_LEVEL, "shouldPartiallyUnroll %s frequency too low %s ", loopBegin, loopFrequency); |
| return false; |
| } |
| loopBegin.setLoopOrigFrequency(loopFrequency); |
| } |
| int maxUnroll = Options.UnrollMaxIterations.getValue(options); |
| // Now correct size for the next unroll. UnrollMaxIterations == 1 means perform the |
| // pre/main/post transformation but don't actually unroll the main loop. |
| size += size; |
| if (maxUnroll == 1 && loopBegin.isSimpleLoop() || size <= maxNodes && unrollFactor < maxUnroll) { |
| // Will the next unroll fit? |
| if ((int) loopBegin.loopOrigFrequency() < (unrollFactor * 2)) { |
| return false; |
| } |
| // Check whether we're allowed to unroll this loop |
| for (Node node : loop.inside().nodes()) { |
| if (node instanceof ControlFlowAnchorNode) { |
| return false; |
| } |
| if (node instanceof InvokeNode) { |
| return false; |
| } |
| } |
| return true; |
| } else { |
| loopBegin.getDebug().log(DebugContext.VERBOSE_LEVEL, "shouldPartiallyUnroll %s unrolled loop is too large %s ", loopBegin, size); |
| return false; |
| } |
| } |
| |
| @Override |
| public boolean shouldTryUnswitch(LoopEx loop) { |
| LoopBeginNode loopBegin = loop.loopBegin(); |
| double loopFrequency = loopBegin.loopFrequency(); |
| if (loopFrequency <= 1.0) { |
| return false; |
| } |
| OptionValues options = loop.entryPoint().getOptions(); |
| return loopBegin.unswitches() <= LoopMaxUnswitch.getValue(options); |
| } |
| |
| private static final class CountingClosure implements VirtualClosure { |
| int count; |
| |
| @Override |
| public void apply(VirtualState node) { |
| count++; |
| } |
| } |
| |
| private static class IsolatedInitialization { |
| static final CounterKey UNSWITCH_SPLIT_WITH_PHIS = DebugContext.counter("UnswitchSplitWithPhis"); |
| } |
| |
| @Override |
| public boolean shouldUnswitch(LoopEx loop, List<ControlSplitNode> controlSplits) { |
| int phis = 0; |
| StructuredGraph graph = loop.loopBegin().graph(); |
| DebugContext debug = graph.getDebug(); |
| NodeBitMap branchNodes = 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(debug); |
| phis += ((MergeNode) postDomBlock.getBeginNode()).phis().count(); |
| } |
| } |
| int inBranchTotal = branchNodes.count(); |
| |
| CountingClosure stateNodesCount = new CountingClosure(); |
| double loopFrequency = loop.loopBegin().loopFrequency(); |
| OptionValues options = loop.loopBegin().getOptions(); |
| int maxDiff = Options.LoopUnswitchTrivial.getValue(options) + (int) (Options.LoopUnswitchFrequencyBoost.getValue(options) * (loopFrequency - 1.0 + phis)); |
| |
| maxDiff = Math.min(maxDiff, Options.LoopUnswitchMaxIncrease.getValue(options)); |
| int remainingGraphSpace = MaximumDesiredSize.getValue(options) - 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; |
| } |
| } |
| |
| } |
