Mercurial > hg > truffle
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/LoopBeginNode.java @ 18995:a2cb19764970
Rename MergeNode to AbstractMergeNode.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Wed, 28 Jan 2015 01:04:20 +0100 |
parents | 8b4ef818169c |
children | 9865883b5114 |
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/* * Copyright (c) 2011, 2014, 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.nodes; import static com.oracle.graal.graph.iterators.NodePredicates.*; import java.util.*; import com.oracle.graal.compiler.common.type.*; import com.oracle.graal.graph.*; import com.oracle.graal.graph.iterators.*; import com.oracle.graal.graph.spi.*; import com.oracle.graal.nodeinfo.*; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.extended.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.nodes.util.*; @NodeInfo public class LoopBeginNode extends AbstractMergeNode implements IterableNodeType, LIRLowerable { protected double loopFrequency; protected int nextEndIndex; protected int unswitches; @OptionalInput(InputType.Guard) GuardingNode overflowGuard; public LoopBeginNode() { loopFrequency = 1; } public double loopFrequency() { return loopFrequency; } public void setLoopFrequency(double loopFrequency) { assert loopFrequency >= 0; this.loopFrequency = loopFrequency; } /** * Returns the <b>unordered</b> set of {@link LoopEndNode} that correspond to back-edges for * this loop. The order of the back-edges is unspecified, if you need to get an ordering * compatible for {@link PhiNode} creation, use {@link #orderedLoopEnds()}. * * @return the set of {@code LoopEndNode} that correspond to back-edges for this loop */ public NodeIterable<LoopEndNode> loopEnds() { return usages().filter(LoopEndNode.class); } public NodeIterable<LoopExitNode> loopExits() { return usages().filter(LoopExitNode.class); } @Override public NodeIterable<Node> anchored() { return super.anchored().filter(isNotA(LoopEndNode.class).nor(LoopExitNode.class)); } /** * Returns the set of {@link LoopEndNode} that correspond to back-edges for this loop, ordered * in increasing {@link #phiPredecessorIndex}. This method is suited to create new loop * {@link PhiNode}. * * @return the set of {@code LoopEndNode} that correspond to back-edges for this loop */ public List<LoopEndNode> orderedLoopEnds() { List<LoopEndNode> snapshot = loopEnds().snapshot(); Collections.sort(snapshot, new Comparator<LoopEndNode>() { @Override public int compare(LoopEndNode o1, LoopEndNode o2) { return o1.endIndex() - o2.endIndex(); } }); return snapshot; } public AbstractEndNode forwardEnd() { assert forwardEndCount() == 1; return forwardEndAt(0); } @Override public void generate(NodeLIRBuilderTool gen) { // Nothing to emit, since this is node is used for structural purposes only. } @Override protected void deleteEnd(AbstractEndNode end) { if (end instanceof LoopEndNode) { LoopEndNode loopEnd = (LoopEndNode) end; loopEnd.setLoopBegin(null); int idx = loopEnd.endIndex(); for (LoopEndNode le : loopEnds()) { int leIdx = le.endIndex(); assert leIdx != idx; if (leIdx > idx) { le.setEndIndex(leIdx - 1); } } nextEndIndex--; } else { super.deleteEnd(end); } } @Override public int phiPredecessorCount() { return forwardEndCount() + loopEnds().count(); } @Override public int phiPredecessorIndex(AbstractEndNode pred) { if (pred instanceof LoopEndNode) { LoopEndNode loopEnd = (LoopEndNode) pred; if (loopEnd.loopBegin() == this) { assert loopEnd.endIndex() < loopEnds().count() : "Invalid endIndex : " + loopEnd; return loopEnd.endIndex() + forwardEndCount(); } } else { return super.forwardEndIndex(pred); } throw ValueNodeUtil.shouldNotReachHere("unknown pred : " + pred); } @Override public AbstractEndNode phiPredecessorAt(int index) { if (index < forwardEndCount()) { return forwardEndAt(index); } for (LoopEndNode end : loopEnds()) { int idx = index - forwardEndCount(); assert idx >= 0; if (end.endIndex() == idx) { return end; } } throw ValueNodeUtil.shouldNotReachHere(); } @Override public boolean verify() { assertTrue(loopEnds().isNotEmpty(), "missing loopEnd"); return super.verify(); } public int nextEndIndex() { return nextEndIndex++; } public int unswitches() { return unswitches; } public void incUnswitches() { unswitches++; } @Override public void simplify(SimplifierTool tool) { removeDeadPhis(); canonicalizePhis(tool); } public boolean isLoopExit(AbstractBeginNode begin) { return begin instanceof LoopExitNode && ((LoopExitNode) begin).loopBegin() == this; } public void removeExits() { for (LoopExitNode loopexit : loopExits().snapshot()) { loopexit.removeProxies(); FrameState loopStateAfter = loopexit.stateAfter(); graph().replaceFixedWithFixed(loopexit, graph().add(new BeginNode())); if (loopStateAfter != null && loopStateAfter.isAlive() && loopStateAfter.hasNoUsages()) { GraphUtil.killWithUnusedFloatingInputs(loopStateAfter); } } } public GuardingNode getOverflowGuard() { return overflowGuard; } public void setOverflowGuard(GuardingNode overflowGuard) { updateUsagesInterface(this.overflowGuard, overflowGuard); this.overflowGuard = overflowGuard; } /** * Removes dead {@linkplain PhiNode phi nodes} hanging from this node. * * This method uses the heuristic that any node which not a phi node of this LoopBeginNode is * alive. This allows the removal of dead phi loops. */ public void removeDeadPhis() { if (phis().isNotEmpty()) { Set<PhiNode> alive = Node.newSet(); for (PhiNode phi : phis()) { NodePredicate isAlive = u -> !isPhiAtMerge(u) || alive.contains(u); if (phi.usages().filter(isAlive).isNotEmpty()) { alive.add(phi); for (PhiNode keptAlive : phi.values().filter(PhiNode.class).filter(isAlive.negate())) { alive.add(keptAlive); } } } for (PhiNode phi : phis().filter(((NodePredicate) alive::contains).negate()).snapshot()) { phi.replaceAtUsages(null); phi.safeDelete(); } } } private static final int NO_INCREMENT = Integer.MIN_VALUE; /** * Returns an array with one entry for each input of the phi, which is either * {@link #NO_INCREMENT} or the increment, i.e., the value by which the phi is incremented in * the corresponding branch. */ private static int[] getSelfIncrements(PhiNode phi) { int[] selfIncrement = new int[phi.valueCount()]; for (int i = 0; i < phi.valueCount(); i++) { ValueNode input = phi.valueAt(i); long increment = NO_INCREMENT; if (input != null && input instanceof AddNode && input.stamp() instanceof IntegerStamp) { AddNode add = (AddNode) input; if (add.getX() == phi && add.getY().isConstant()) { increment = add.getY().asJavaConstant().asLong(); } else if (add.getY() == phi && add.getX().isConstant()) { increment = add.getX().asJavaConstant().asLong(); } } else if (input == phi) { increment = 0; } if (increment < Integer.MIN_VALUE || increment > Integer.MAX_VALUE || increment == NO_INCREMENT) { increment = NO_INCREMENT; } selfIncrement[i] = (int) increment; } return selfIncrement; } /** * Coalesces loop phis that represent the same value (which is not handled by normal Global * Value Numbering). */ public void canonicalizePhis(SimplifierTool tool) { int phiCount = phis().count(); if (phiCount > 1) { int phiInputCount = phiPredecessorCount(); int phiIndex = 0; int[][] selfIncrement = new int[phiCount][]; PhiNode[] phis = this.phis().snapshot().toArray(new PhiNode[phiCount]); for (phiIndex = 0; phiIndex < phiCount; phiIndex++) { PhiNode phi = phis[phiIndex]; if (phi != null) { nextPhi: for (int otherPhiIndex = phiIndex + 1; otherPhiIndex < phiCount; otherPhiIndex++) { PhiNode otherPhi = phis[otherPhiIndex]; if (otherPhi == null || phi.getNodeClass() != otherPhi.getNodeClass() || !phi.valueEquals(otherPhi)) { continue nextPhi; } if (selfIncrement[phiIndex] == null) { selfIncrement[phiIndex] = getSelfIncrements(phi); } if (selfIncrement[otherPhiIndex] == null) { selfIncrement[otherPhiIndex] = getSelfIncrements(otherPhi); } int[] phiIncrement = selfIncrement[phiIndex]; int[] otherPhiIncrement = selfIncrement[otherPhiIndex]; for (int inputIndex = 0; inputIndex < phiInputCount; inputIndex++) { if (phiIncrement[inputIndex] == NO_INCREMENT) { if (phi.valueAt(inputIndex) != otherPhi.valueAt(inputIndex)) { continue nextPhi; } } if (phiIncrement[inputIndex] != otherPhiIncrement[inputIndex]) { continue nextPhi; } } if (tool != null) { tool.addToWorkList(otherPhi.usages()); } otherPhi.replaceAtUsages(phi); GraphUtil.killWithUnusedFloatingInputs(otherPhi); phis[otherPhiIndex] = null; } } } } } }