Mercurial > hg > truffle
view graal/com.oracle.graal.loop/src/com/oracle/graal/loop/LoopPolicies.java @ 14106:ca37cb080dad
reorganized graalCompilerToVM.cpp
author | twisti |
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date | Thu, 06 Mar 2014 22:45:25 -0800 |
parents | dca16b3416ab |
children | df2ef5204f2b |
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/* * Copyright (c) 2012, 2012, 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.phases.GraalOptions.*; import com.oracle.graal.debug.*; import com.oracle.graal.graph.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.cfg.*; import com.oracle.graal.nodes.util.*; public abstract class LoopPolicies { private LoopPolicies() { // does not need to be instantiated } // TODO (gd) change when inversion is available public static boolean shouldPeel(LoopEx loop, NodesToDoubles probabilities) { if (loop.detectCounted()) { return false; } LoopBeginNode loopBegin = loop.loopBegin(); double entryProbability = probabilities.get(loopBegin.forwardEnd()); return entryProbability > MinimumPeelProbability.getValue() && loop.size() + loopBegin.graph().getNodeCount() < MaximumDesiredSize.getValue(); } 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()); return size * maxTrips <= maxNodes; } public static boolean shouldTryUnswitch(LoopEx loop) { return loop.loopBegin().unswitches() <= LoopMaxUnswitch.getValue(); } public static boolean shouldUnswitch(LoopEx loop, ControlSplitNode controlSplit) { Block postDomBlock = loop.loopsData().controlFlowGraph().blockFor(controlSplit).getPostdominator(); AbstractBeginNode postDom = postDomBlock != null ? postDomBlock.getBeginNode() : null; int loopTotal = loop.size(); int inBranchTotal = 0; double maxProbability = 0; for (Node successor : controlSplit.successors()) { AbstractBeginNode branch = (AbstractBeginNode) successor; inBranchTotal += loop.nodesInLoopFrom(branch, postDom).cardinality(); // this may count // twice because // of fall-through // in switches double probability = controlSplit.probability(branch); if (probability > maxProbability) { maxProbability = probability; } } int netDiff = loopTotal - (inBranchTotal); double uncertainty = 1 - maxProbability; int maxDiff = LoopUnswitchMaxIncrease.getValue() + (int) (LoopUnswitchUncertaintyBoost.getValue() * loop.loopBegin().loopFrequency() * uncertainty); Debug.log("shouldUnswitch(%s, %s) : delta=%d, max=%d, %.2f%% inside of branches", loop, controlSplit, netDiff, maxDiff, (double) (inBranchTotal) / loopTotal * 100); return netDiff <= maxDiff; } }