Mercurial > hg > graal-compiler
view graal/com.oracle.graal.loop/src/com/oracle/graal/loop/LoopPolicies.java @ 20069:2dbfa1ed5efa
Reduce usages of fixed node probability cache.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Mon, 30 Mar 2015 00:54:07 +0200 |
parents | fdb93d2ed5c8 |
children | b1530a6cce8c |
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/* * Copyright (c) 2012, 2015, 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.loop; import static com.oracle.graal.compiler.common.GraalOptions.*; import java.util.*; import com.oracle.graal.debug.*; import com.oracle.graal.graph.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.VirtualState.VirtualClosure; import com.oracle.graal.nodes.cfg.*; import com.oracle.graal.nodes.debug.*; import com.oracle.graal.options.*; public abstract class 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); private LoopPolicies() { // does not need to be instantiated } // TODO (gd) change when inversion is available public static boolean shouldPeel(LoopEx loop, ControlFlowGraph cfg) { if (loop.detectCounted()) { return false; } 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 for (Node node : loop.inside().nodes()) { if (node instanceof ControlFlowAnchorNode) { return false; } } return true; } else { return false; } } public static 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, MaximumDesiredSize.getValue() - loop.loopBegin().graph().getNodeCount()); int size = Math.max(1, loop.size() - 1 - loop.loopBegin().phis().count()); if (size * maxTrips <= maxNodes) { // check whether we're allowed to unroll this loop for (Node node : loop.inside().nodes()) { if (node instanceof ControlFlowAnchorNode) { return false; } } return true; } else { return false; } } public static 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; public void apply(VirtualState node) { count++; } } private static class IsolatedInitialization { static final DebugMetric UNSWITCH_SPLIT_WITH_PHIS = Debug.metric("UnswitchSplitWithPhis"); } public static boolean shouldUnswitch(LoopEx loop, List<ControlSplitNode> controlSplits) { int inBranchTotal = 0; int phis = 0; for (ControlSplitNode controlSplit : controlSplits) { for (Node successor : controlSplit.successors()) { AbstractBeginNode branch = (AbstractBeginNode) successor; // this may count twice because of fall-through in switches inBranchTotal += loop.nodesInLoopBranch(branch).count(); } Block postDomBlock = loop.loopsData().getCFG().blockFor(controlSplit).getPostdominator(); if (postDomBlock != null) { IsolatedInitialization.UNSWITCH_SPLIT_WITH_PHIS.increment(); phis += ((MergeNode) postDomBlock.getBeginNode()).phis().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; 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); return actualDiff <= maxDiff; } }