Mercurial > hg > truffle
view graal/com.oracle.graal.loop/src/com/oracle/graal/loop/LoopEx.java @ 19192:a7fb05f3d7e1
Move induction variable detection logic into LoopEx
author | Tom Rodriguez <tom.rodriguez@oracle.com> |
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date | Mon, 09 Feb 2015 16:00:00 -0800 |
parents | 480bd3b1adcd |
children | b42653236a83 |
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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.graph.Node.*; import java.util.*; import com.oracle.graal.compiler.common.*; import com.oracle.graal.compiler.common.calc.*; import com.oracle.graal.compiler.common.cfg.*; import com.oracle.graal.compiler.common.type.*; import com.oracle.graal.debug.*; import com.oracle.graal.graph.*; import com.oracle.graal.graph.iterators.*; import com.oracle.graal.loop.InductionVariable.Direction; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.cfg.*; import com.oracle.graal.nodes.extended.*; import com.oracle.graal.nodes.util.*; public class LoopEx { private final Loop<Block> loop; private LoopFragmentInside inside; private LoopFragmentWhole whole; private CountedLoopInfo counted; // TODO (gd) detect private LoopsData data; private Map<Node, InductionVariable> ivs; LoopEx(Loop<Block> loop, LoopsData data) { this.loop = loop; this.data = data; } public Loop<Block> loop() { return loop; } public LoopFragmentInside inside() { if (inside == null) { inside = new LoopFragmentInside(this); } return inside; } public LoopFragmentWhole whole() { if (whole == null) { whole = new LoopFragmentWhole(this); } return whole; } public void invalidateFragments() { inside = null; whole = null; } @SuppressWarnings("unused") public LoopFragmentInsideFrom insideFrom(FixedNode point) { // TODO (gd) return null; } @SuppressWarnings("unused") public LoopFragmentInsideBefore insideBefore(FixedNode point) { // TODO (gd) return null; } public boolean isOutsideLoop(Node n) { return !whole().contains(n); } public LoopBeginNode loopBegin() { return (LoopBeginNode) loop().getHeader().getBeginNode(); } public FixedNode predecessor() { return (FixedNode) loopBegin().forwardEnd().predecessor(); } public FixedNode entryPoint() { return loopBegin().forwardEnd(); } public boolean isCounted() { return counted != null; } public CountedLoopInfo counted() { return counted; } public LoopEx parent() { if (loop.getParent() == null) { return null; } return data.loop(loop.getParent()); } public int size() { return whole().nodes().count(); } @Override public String toString() { return (isCounted() ? "CountedLoop [" + counted() + "] " : "Loop ") + "(depth=" + loop().getDepth() + ") " + loopBegin(); } private class InvariantPredicate implements NodePredicate { @Override public boolean apply(Node n) { return isOutsideLoop(n); } } public void reassociateInvariants() { InvariantPredicate invariant = new InvariantPredicate(); StructuredGraph graph = loopBegin().graph(); for (BinaryArithmeticNode<?> binary : whole().nodes().filter(BinaryArithmeticNode.class)) { if (!binary.isAssociative()) { continue; } BinaryArithmeticNode<?> result = BinaryArithmeticNode.reassociate(binary, invariant, binary.getX(), binary.getY()); if (result != binary) { if (Debug.isLogEnabled()) { Debug.log("%s : Reassociated %s into %s", graph.method().format("%H::%n"), binary, result); } if (!result.isAlive()) { assert !result.isDeleted(); result = graph.addOrUniqueWithInputs(result); } binary.replaceAtUsages(result); GraphUtil.killWithUnusedFloatingInputs(binary); } } } public boolean detectCounted() { LoopBeginNode loopBegin = loopBegin(); FixedNode next = loopBegin.next(); while (next instanceof FixedGuardNode || next instanceof ValueAnchorNode) { next = ((FixedWithNextNode) next).next(); } if (next instanceof IfNode) { IfNode ifNode = (IfNode) next; boolean negated = false; if (!loopBegin.isLoopExit(ifNode.falseSuccessor())) { if (!loopBegin.isLoopExit(ifNode.trueSuccessor())) { return false; } negated = true; } LogicNode ifTest = ifNode.condition(); if (!(ifTest instanceof IntegerLessThanNode)) { if (ifTest instanceof IntegerBelowNode) { Debug.log("Ignored potential Counted loop at %s with |<|", loopBegin); } return false; } IntegerLessThanNode lessThan = (IntegerLessThanNode) ifTest; Condition condition = null; InductionVariable iv = null; ValueNode limit = null; if (isOutsideLoop(lessThan.getX())) { iv = getInductionVariables().get(lessThan.getY()); if (iv != null) { condition = lessThan.condition().mirror(); limit = lessThan.getX(); } } else if (isOutsideLoop(lessThan.getY())) { iv = getInductionVariables().get(lessThan.getX()); if (iv != null) { condition = lessThan.condition(); limit = lessThan.getY(); } } if (condition == null) { return false; } if (negated) { condition = condition.negate(); } boolean oneOff = false; switch (condition) { case LE: oneOff = true; // fall through case LT: if (iv.direction() != Direction.Up) { return false; } break; case GE: oneOff = true; // fall through case GT: if (iv.direction() != Direction.Down) { return false; } break; default: throw GraalInternalError.shouldNotReachHere(); } counted = new CountedLoopInfo(this, iv, limit, oneOff, negated ? ifNode.falseSuccessor() : ifNode.trueSuccessor()); return true; } return false; } public LoopsData loopsData() { return data; } public NodeBitMap nodesInLoopFrom(AbstractBeginNode point, AbstractBeginNode until) { Collection<AbstractBeginNode> blocks = new LinkedList<>(); Collection<LoopExitNode> exits = new LinkedList<>(); Queue<Block> work = new LinkedList<>(); ControlFlowGraph cfg = loopsData().controlFlowGraph(); work.add(cfg.blockFor(point)); Block untilBlock = until != null ? cfg.blockFor(until) : null; while (!work.isEmpty()) { Block b = work.remove(); if (b == untilBlock) { continue; } if (loop().getExits().contains(b)) { exits.add((LoopExitNode) b.getBeginNode()); } else if (loop().getBlocks().contains(b)) { blocks.add(b.getBeginNode()); work.addAll(b.getDominated()); } } return LoopFragment.computeNodes(point.graph(), blocks, exits); } public Map<Node, InductionVariable> getInductionVariables() { if (ivs == null) { ivs = findInductionVariables(this); } return ivs; } /** * Collect all the basic induction variables for the loop and the find any induction variables * which are derived from the basic ones. * * @param loop * @return a map from node to induction variable */ private static Map<Node, InductionVariable> findInductionVariables(LoopEx loop) { Map<Node, InductionVariable> ivs = newIdentityMap(); Queue<InductionVariable> scanQueue = new LinkedList<>(); LoopBeginNode loopBegin = loop.loopBegin(); AbstractEndNode forwardEnd = loopBegin.forwardEnd(); for (PhiNode phi : loopBegin.phis().filter(ValuePhiNode.class)) { ValueNode backValue = phi.singleBackValue(); if (backValue == PhiNode.MULTIPLE_VALUES) { continue; } ValueNode stride = addSub(loop, backValue, phi); if (stride != null) { BasicInductionVariable biv = new BasicInductionVariable(loop, (ValuePhiNode) phi, phi.valueAt(forwardEnd), stride, (BinaryArithmeticNode<?>) backValue); ivs.put(phi, biv); scanQueue.add(biv); } } while (!scanQueue.isEmpty()) { InductionVariable baseIv = scanQueue.remove(); ValueNode baseIvNode = baseIv.valueNode(); for (ValueNode op : baseIvNode.usages().filter(ValueNode.class)) { if (loop.isOutsideLoop(op)) { continue; } if (op.usages().count() == 1 && op.usages().first() == baseIvNode) { /* * This is just the base induction variable increment with no other uses so * don't bother reporting it. */ continue; } InductionVariable iv = null; ValueNode offset = addSub(loop, op, baseIvNode); ValueNode scale; if (offset != null) { iv = new DerivedOffsetInductionVariable(loop, baseIv, offset, (BinaryArithmeticNode<?>) op); } else if (op instanceof NegateNode) { iv = new DerivedScaledInductionVariable(loop, baseIv, (NegateNode) op); } else if ((scale = mul(loop, op, baseIvNode)) != null) { iv = new DerivedScaledInductionVariable(loop, baseIv, scale, op); } if (iv != null) { ivs.put(op, iv); scanQueue.offer(iv); } } } return Collections.unmodifiableMap(ivs); } private static ValueNode addSub(LoopEx loop, ValueNode op, ValueNode base) { if (op.stamp() instanceof IntegerStamp && (op instanceof AddNode || op instanceof SubNode)) { BinaryArithmeticNode<?> aritOp = (BinaryArithmeticNode<?>) op; if (aritOp.getX() == base && loop.isOutsideLoop(aritOp.getY())) { return aritOp.getY(); } else if (aritOp.getY() == base && loop.isOutsideLoop(aritOp.getX())) { return aritOp.getX(); } } return null; } private static ValueNode mul(LoopEx loop, ValueNode op, ValueNode base) { if (op instanceof MulNode) { MulNode mul = (MulNode) op; if (mul.getX() == base && loop.isOutsideLoop(mul.getY())) { return mul.getY(); } else if (mul.getY() == base && loop.isOutsideLoop(mul.getX())) { return mul.getX(); } } if (op instanceof LeftShiftNode) { LeftShiftNode shift = (LeftShiftNode) op; if (shift.getX() == base && shift.getY().isConstant()) { return ConstantNode.forInt(1 << shift.getY().asJavaConstant().asInt(), base.graph()); } } return null; } /** * Deletes any nodes created within the scope of this object that have no usages. */ public void deleteUnusedNodes() { if (ivs != null) { for (InductionVariable iv : ivs.values()) { iv.deleteUnusedNodes(); } } } }