Mercurial > hg > truffle
changeset 15583:d331b7c3d7c4
[single-pass-iter] start of evolution towards a node iterator less memory-hungry
author | Miguel Garcia <miguel.m.garcia@oracle.com> |
---|---|
date | Fri, 09 May 2014 16:22:54 +0200 |
parents | 9a5b5a5b2246 |
children | 56ab99b480af |
files | graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/ConditionalEliminationPhase.java graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/ValueAnchorCleanupPhase.java graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/cfs/BaseReduction.java graal/com.oracle.graal.phases/src/com/oracle/graal/phases/graph/SinglePassNodeIterator.java |
diffstat | 4 files changed, 255 insertions(+), 4 deletions(-) [+] |
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--- a/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/ConditionalEliminationPhase.java Fri May 09 14:45:48 2014 +0200 +++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/ConditionalEliminationPhase.java Fri May 09 16:22:54 2014 +0200 @@ -332,7 +332,7 @@ } } - public class ConditionalElimination extends PostOrderNodeIterator<State> { + public class ConditionalElimination extends SinglePassNodeIterator<State> { private final LogicNode trueConstant; private final LogicNode falseConstant;
--- a/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/ValueAnchorCleanupPhase.java Fri May 09 14:45:48 2014 +0200 +++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/ValueAnchorCleanupPhase.java Fri May 09 16:22:54 2014 +0200 @@ -63,7 +63,7 @@ } } - private static class CleanupValueAnchorsClosure extends PostOrderNodeIterator<State> { + private static class CleanupValueAnchorsClosure extends SinglePassNodeIterator<State> { public CleanupValueAnchorsClosure(FixedNode start) { super(start, new State());
--- a/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/cfs/BaseReduction.java Fri May 09 14:45:48 2014 +0200 +++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/cfs/BaseReduction.java Fri May 09 16:22:54 2014 +0200 @@ -30,7 +30,7 @@ import com.oracle.graal.graph.spi.CanonicalizerTool; import com.oracle.graal.nodes.*; import com.oracle.graal.compiler.common.type.ObjectStamp; -import com.oracle.graal.phases.graph.PostOrderNodeIterator; +import com.oracle.graal.phases.graph.SinglePassNodeIterator; import com.oracle.graal.phases.tiers.PhaseContext; import java.util.ArrayList; @@ -55,7 +55,7 @@ * </p> * */ -public abstract class BaseReduction extends PostOrderNodeIterator<State> { +public abstract class BaseReduction extends SinglePassNodeIterator<State> { protected static final DebugMetric metricCheckCastRemoved = Debug.metric("FSR-CheckCastRemoved"); protected static final DebugMetric metricGuardingPiNodeRemoved = Debug.metric("FSR-GuardingPiNodeRemoved");
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.graal.phases/src/com/oracle/graal/phases/graph/SinglePassNodeIterator.java Fri May 09 16:22:54 2014 +0200 @@ -0,0 +1,251 @@ +/* + * Copyright (c) 2011, 2011, 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.graph; + +import java.util.*; + +import com.oracle.graal.graph.*; +import com.oracle.graal.graph.util.*; +import com.oracle.graal.nodes.*; + +/** + * A SinglePassNodeIterator iterates the fixed nodes of the graph in post order starting from a + * specified fixed node. Unlike in iterative dataflow analysis, a single pass is performed, which + * allows keeping a smaller working set of pending {@link MergeableState}. This iteration scheme + * requires: + * <ul> + * <li>{@link MergeableState#merge(MergeNode, List)} to always return <code>true</code> (an + * assertion checks this)</li> + * <li>{@link #controlSplit(ControlSplitNode)} to always return all successors (otherwise, not all + * associated {@link EndNode} will be visited. In turn, visiting all the end nodes for a given + * {@link MergeNode} is a precondition before that merge node can be visited)</li> + * </ul> + * + * <p> + * For this iterator the CFG is defined by the classical CFG nodes ( + * {@link com.oracle.graal.nodes.ControlSplitNode}, {@link com.oracle.graal.nodes.MergeNode}...) and + * the {@link com.oracle.graal.nodes.FixedWithNextNode#next() next} pointers of + * {@link com.oracle.graal.nodes.FixedWithNextNode}. + * </p> + * + * <p> + * The lifecycle that single-pass node iterators go through is described in {@link #apply()} + * </p> + * + * @param <T> the type of {@link MergeableState} handled by this SinglePassNodeIterator + */ +public abstract class SinglePassNodeIterator<T extends MergeableState<T>> { + + private final NodeBitMap visitedEnds; + private final Deque<BeginNode> nodeQueue; + private final Map<FixedNode, T> nodeStates; + private final FixedNode start; + + protected T state; + + public SinglePassNodeIterator(FixedNode start, T initialState) { + StructuredGraph graph = start.graph(); + visitedEnds = graph.createNodeBitMap(); + nodeQueue = new ArrayDeque<>(); + nodeStates = CollectionsAccess.newNodeIdentityMap(); + this.start = start; + this.state = initialState; + } + + /** + * Performs a single-pass iteration. + * + * <p> + * After this method has been invoked, the {@link SinglePassNodeIterator} instance can't be used + * again. This saves clearing up fields in {@link #finished()}, the assumption being that this + * instance will be garbage-collected soon afterwards. + * </p> + */ + public void apply() { + FixedNode current = start; + + do { + if (current instanceof InvokeWithExceptionNode) { + invoke((Invoke) current); + queueSuccessors(current, null); + current = nextQueuedNode(); + } else if (current instanceof LoopBeginNode) { + state.loopBegin((LoopBeginNode) current); + nodeStates.put(current, state); + state = state.clone(); + loopBegin((LoopBeginNode) current); + current = ((LoopBeginNode) current).next(); + assert current != null; + } else if (current instanceof LoopEndNode) { + loopEnd((LoopEndNode) current); + finishLoopEnds((LoopEndNode) current); + current = nextQueuedNode(); + } else if (current instanceof MergeNode) { + merge((MergeNode) current); + current = ((MergeNode) current).next(); + assert current != null; + } else if (current instanceof FixedWithNextNode) { + FixedNode next = ((FixedWithNextNode) current).next(); + assert next != null : current; + node(current); + current = next; + } else if (current instanceof EndNode) { + end((EndNode) current); + queueMerge((EndNode) current); + current = nextQueuedNode(); + } else if (current instanceof ControlSinkNode) { + node(current); + current = nextQueuedNode(); + } else if (current instanceof ControlSplitNode) { + Set<Node> successors = controlSplit((ControlSplitNode) current); + queueSuccessors(current, successors); + current = nextQueuedNode(); + } else { + assert false : current; + } + } while (current != null); + finished(); + } + + private void queueSuccessors(FixedNode x, Set<Node> successors) { + nodeStates.put(x, state); + if (successors != null) { + for (Node node : successors) { + if (node != null) { + nodeStates.put((FixedNode) node.predecessor(), state); + nodeQueue.addFirst((BeginNode) node); + } + } + } else { + for (Node node : x.successors()) { + if (node != null) { + nodeQueue.addFirst((BeginNode) node); + } + } + } + } + + private FixedNode nextQueuedNode() { + int maxIterations = nodeQueue.size(); + while (maxIterations-- > 0) { + BeginNode node = nodeQueue.removeFirst(); + if (node instanceof MergeNode) { + MergeNode merge = (MergeNode) node; + state = nodeStates.get(merge.forwardEndAt(0)).clone(); + ArrayList<T> states = new ArrayList<>(merge.forwardEndCount() - 1); + for (int i = 1; i < merge.forwardEndCount(); i++) { + T other = nodeStates.get(merge.forwardEndAt(i)); + assert other != null; + states.add(other); + } + boolean ready = state.merge(merge, states); + assert ready; + if (ready) { + return merge; + } else { + nodeQueue.addLast(merge); + } + } else { + assert node.predecessor() != null; + state = nodeStates.get(node.predecessor()).clone(); + state.afterSplit(node); + return node; + } + } + return null; + } + + private void finishLoopEnds(LoopEndNode end) { + assert !visitedEnds.isMarked(end); + assert !nodeStates.containsKey(end); + nodeStates.put(end, state); + visitedEnds.mark(end); + LoopBeginNode begin = end.loopBegin(); + boolean endsVisited = true; + for (LoopEndNode le : begin.loopEnds()) { + if (!visitedEnds.isMarked(le)) { + endsVisited = false; + break; + } + } + if (endsVisited) { + ArrayList<T> states = new ArrayList<>(begin.loopEnds().count()); + for (LoopEndNode le : begin.orderedLoopEnds()) { + states.add(nodeStates.get(le)); + } + T loopBeginState = nodeStates.get(begin); + if (loopBeginState != null) { + loopBeginState.loopEnds(begin, states); + } + } + } + + private void queueMerge(EndNode end) { + assert !visitedEnds.isMarked(end); + assert !nodeStates.containsKey(end); + nodeStates.put(end, state); + visitedEnds.mark(end); + MergeNode merge = end.merge(); + boolean endsVisited = true; + for (int i = 0; i < merge.forwardEndCount(); i++) { + if (!visitedEnds.isMarked(merge.forwardEndAt(i))) { + endsVisited = false; + break; + } + } + if (endsVisited) { + nodeQueue.add(merge); + } + } + + protected abstract void node(FixedNode node); + + protected void end(EndNode endNode) { + node(endNode); + } + + protected void merge(MergeNode merge) { + node(merge); + } + + protected void loopBegin(LoopBeginNode loopBegin) { + node(loopBegin); + } + + protected void loopEnd(LoopEndNode loopEnd) { + node(loopEnd); + } + + protected Set<Node> controlSplit(ControlSplitNode controlSplit) { + node(controlSplit); + return null; + } + + protected void invoke(Invoke invoke) { + node(invoke.asNode()); + } + + protected void finished() { + // nothing to do + } +}