Mercurial > hg > truffle
view graal/com.oracle.graal.loop/src/com/oracle/graal/loop/LoopPolicies.java @ 19162:c06f39fa2228
Move HIR independent utilities to c.o.g.compiler.common.
author | Josef Eisl <josef.eisl@jku.at> |
---|---|
date | Wed, 04 Feb 2015 18:24:05 +0100 |
parents | 81e464d45137 |
children | b42653236a83 |
line wrap: on
line source
/* * 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 java.util.function.*; 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.debug.*; 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, ToDoubleFunction<FixedNode> probabilities) { if (loop.detectCounted()) { return false; } LoopBeginNode loopBegin = loop.loopBegin(); double entryProbability = probabilities.applyAsDouble(loopBegin.forwardEnd()); 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) { return loop.loopBegin().unswitches() <= LoopMaxUnswitch.getValue(); } public static boolean shouldUnswitch(LoopEx loop, List<ControlSplitNode> controlSplits) { int loopTotal = loop.size(); int inBranchTotal = 0; double maxProbability = 0; for (ControlSplitNode controlSplit : controlSplits) { Block postDomBlock = loop.loopsData().controlFlowGraph().blockFor(controlSplit).getPostdominator(); AbstractBeginNode postDom = postDomBlock != null ? postDomBlock.getBeginNode() : null; for (Node successor : controlSplit.successors()) { AbstractBeginNode branch = (AbstractBeginNode) successor; // this may count twice because of fall-through in switches inBranchTotal += loop.nodesInLoopFrom(branch, postDom).count(); 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, controlSplits, netDiff, maxDiff, (double) (inBranchTotal) / loopTotal * 100); return netDiff <= maxDiff; } }