Mercurial > hg > truffle
view graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/OptimizeGuardAnchorsPhase.java @ 19304:6135f3a3fa45
Truffle-DSL: fix function call example can throw a guard assertion.
author | Christian Humer <christian.humer@gmail.com> |
---|---|
date | Wed, 11 Feb 2015 19:29:35 +0100 |
parents | 480bd3b1adcd |
children | 61d3cb8e1280 |
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/* * Copyright (c) 2013, 2013, 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.phases.common; import java.util.*; import com.oracle.graal.debug.*; import com.oracle.graal.graph.*; import com.oracle.graal.graph.iterators.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.cfg.*; import com.oracle.graal.nodes.extended.*; import com.oracle.graal.phases.*; public class OptimizeGuardAnchorsPhase extends Phase { private static final DebugMetric metricGuardsAnchorOptimized = Debug.metric("GuardsAnchorOptimized"); private static final DebugMetric metricGuardsOptimizedAtSplit = Debug.metric("GuardsOptimizedAtSplit"); public static class LazyCFG { private ControlFlowGraph cfg; private StructuredGraph graph; public LazyCFG(StructuredGraph graph) { this.graph = graph; } public ControlFlowGraph get() { if (cfg == null) { cfg = ControlFlowGraph.compute(graph, true, false, true, true); } return cfg; } } @Override protected void run(StructuredGraph graph) { LazyCFG cfg = new LazyCFG(graph); for (AbstractBeginNode begin : graph.getNodes(AbstractBeginNode.class)) { if (!(begin instanceof StartNode || begin.predecessor() instanceof ControlSplitNode)) { NodeIterable<GuardNode> guards = begin.guards(); if (guards.isNotEmpty()) { AbstractBeginNode newAnchor = computeOptimalAnchor(cfg.get(), begin); // newAnchor == begin is possible because postdominator computation assumes that // loops never end if (newAnchor != begin) { for (GuardNode guard : guards.snapshot()) { guard.setAnchor(newAnchor); } metricGuardsAnchorOptimized.increment(); } } } } for (ControlSplitNode controlSplit : graph.getNodes(ControlSplitNode.class)) { optimizeAtControlSplit(controlSplit, cfg); } } public static AbstractBeginNode getOptimalAnchor(LazyCFG cfg, AbstractBeginNode begin) { if (begin instanceof StartNode || begin.predecessor() instanceof ControlSplitNode) { return begin; } return computeOptimalAnchor(cfg.get(), begin); } private static AbstractBeginNode computeOptimalAnchor(ControlFlowGraph cfg, AbstractBeginNode begin) { Block anchor = cfg.blockFor(begin); while (anchor.getDominator() != null && anchor.getDominator().getPostdominator() == anchor) { anchor = anchor.getDominator(); } return anchor.getBeginNode(); } private static void optimizeAtControlSplit(ControlSplitNode controlSplit, LazyCFG cfg) { AbstractBeginNode successor = findMinimumUsagesSuccessor(controlSplit); int successorCount = controlSplit.successors().count(); List<GuardNode> otherGuards = new ArrayList<>(successorCount - 1); for (GuardNode guard : successor.guards().snapshot()) { if (guard.isDeleted() || guard.condition().getUsageCount() < successorCount) { continue; } for (GuardNode conditonGuard : guard.condition().usages().filter(GuardNode.class)) { if (conditonGuard != guard) { AnchoringNode conditonGuardAnchor = conditonGuard.getAnchor(); if (conditonGuardAnchor.asNode().predecessor() == controlSplit && compatibleGuards(guard, conditonGuard)) { otherGuards.add(conditonGuard); } } } if (otherGuards.size() == successorCount - 1) { AbstractBeginNode anchor = computeOptimalAnchor(cfg.get(), AbstractBeginNode.prevBegin(controlSplit)); GuardNode newGuard = controlSplit.graph().unique(new GuardNode(guard.condition(), anchor, guard.reason(), guard.action(), guard.isNegated(), guard.getSpeculation())); for (GuardNode otherGuard : otherGuards) { otherGuard.replaceAndDelete(newGuard); } guard.replaceAndDelete(newGuard); metricGuardsOptimizedAtSplit.increment(); } otherGuards.clear(); } } private static boolean compatibleGuards(GuardNode guard, GuardNode conditonGuard) { return conditonGuard.isNegated() == guard.isNegated() && conditonGuard.action() == guard.action() && conditonGuard.reason() == guard.reason() && conditonGuard.getSpeculation().equals(guard.getSpeculation()); } private static AbstractBeginNode findMinimumUsagesSuccessor(ControlSplitNode controlSplit) { NodePosIterator successors = controlSplit.successors().iterator(); AbstractBeginNode min = (AbstractBeginNode) successors.next(); int minUsages = min.getUsageCount(); while (successors.hasNext()) { AbstractBeginNode successor = (AbstractBeginNode) successors.next(); int count = successor.getUsageCount(); if (count < minUsages) { minUsages = count; min = successor; } } return min; } }