--- /dev/null 2016-05-31 09:42:47.975716356 -0700 +++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.lir/src/org/graalvm/compiler/lir/alloc/lsra/OptimizingLinearScanWalker.java 2016-12-09 00:54:08.659626607 -0800 @@ -0,0 +1,263 @@ +/* + * Copyright (c) 2014, 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 org.graalvm.compiler.lir.alloc.lsra; + +import static org.graalvm.compiler.lir.LIRValueUtil.isStackSlotValue; +import static jdk.vm.ci.code.ValueUtil.asRegister; +import static jdk.vm.ci.code.ValueUtil.isRegister; + +import org.graalvm.compiler.core.common.cfg.AbstractBlockBase; +import org.graalvm.compiler.debug.Debug; +import org.graalvm.compiler.debug.Debug.Scope; +import org.graalvm.compiler.debug.Indent; +import org.graalvm.compiler.lir.alloc.lsra.Interval.RegisterBinding; +import org.graalvm.compiler.lir.alloc.lsra.Interval.RegisterBindingLists; +import org.graalvm.compiler.lir.alloc.lsra.Interval.RegisterPriority; +import org.graalvm.compiler.lir.alloc.lsra.Interval.State; +import org.graalvm.compiler.options.Option; +import org.graalvm.compiler.options.OptionType; +import org.graalvm.compiler.options.OptionValue; + +import jdk.vm.ci.code.Register; +import jdk.vm.ci.meta.AllocatableValue; + +public class OptimizingLinearScanWalker extends LinearScanWalker { + + public static class Options { + // @formatter:off + @Option(help = "Enable LSRA optimization", type = OptionType.Debug) + public static final OptionValue LSRAOptimization = new OptionValue<>(false); + @Option(help = "LSRA optimization: Only split but do not reassign", type = OptionType.Debug) + public static final OptionValue LSRAOptSplitOnly = new OptionValue<>(false); + // @formatter:on + } + + OptimizingLinearScanWalker(LinearScan allocator, Interval unhandledFixedFirst, Interval unhandledAnyFirst) { + super(allocator, unhandledFixedFirst, unhandledAnyFirst); + } + + @SuppressWarnings("try") + @Override + protected void handleSpillSlot(Interval interval) { + assert interval.location() != null : "interval not assigned " + interval; + if (interval.canMaterialize()) { + assert !isStackSlotValue(interval.location()) : "interval can materialize but assigned to a stack slot " + interval; + return; + } + assert isStackSlotValue(interval.location()) : "interval not assigned to a stack slot " + interval; + try (Scope s1 = Debug.scope("LSRAOptimization")) { + Debug.log("adding stack to unhandled list %s", interval); + unhandledLists.addToListSortedByStartAndUsePositions(RegisterBinding.Stack, interval); + } + } + + @SuppressWarnings("unused") + private static void printRegisterBindingList(RegisterBindingLists list, RegisterBinding binding) { + for (Interval interval = list.get(binding); interval != Interval.EndMarker; interval = interval.next) { + Debug.log("%s", interval); + } + } + + @SuppressWarnings("try") + @Override + void walk() { + try (Scope s = Debug.scope("OptimizingLinearScanWalker")) { + for (AbstractBlockBase block : allocator.sortedBlocks()) { + optimizeBlock(block); + } + } + super.walk(); + } + + @SuppressWarnings("try") + private void optimizeBlock(AbstractBlockBase block) { + if (block.getPredecessorCount() == 1) { + int nextBlock = allocator.getFirstLirInstructionId(block); + try (Scope s1 = Debug.scope("LSRAOptimization")) { + Debug.log("next block: %s (%d)", block, nextBlock); + } + try (Indent indent0 = Debug.indent()) { + walkTo(nextBlock); + + try (Scope s1 = Debug.scope("LSRAOptimization")) { + boolean changed = true; + // we need to do this because the active lists might change + loop: while (changed) { + changed = false; + try (Indent indent1 = Debug.logAndIndent("Active intervals: (block %s [%d])", block, nextBlock)) { + for (Interval active = activeLists.get(RegisterBinding.Any); active != Interval.EndMarker; active = active.next) { + Debug.log("active (any): %s", active); + if (optimize(nextBlock, block, active, RegisterBinding.Any)) { + changed = true; + break loop; + } + } + for (Interval active = activeLists.get(RegisterBinding.Stack); active != Interval.EndMarker; active = active.next) { + Debug.log("active (stack): %s", active); + if (optimize(nextBlock, block, active, RegisterBinding.Stack)) { + changed = true; + break loop; + } + } + } + } + } + } + } + } + + @SuppressWarnings("try") + private boolean optimize(int currentPos, AbstractBlockBase currentBlock, Interval currentInterval, RegisterBinding binding) { + // BEGIN initialize and sanity checks + assert currentBlock != null : "block must not be null"; + assert currentInterval != null : "interval must not be null"; + + assert currentBlock.getPredecessorCount() == 1 : "more than one predecessors -> optimization not possible"; + + if (!currentInterval.isSplitChild()) { + // interval is not a split child -> no need for optimization + return false; + } + + if (currentInterval.from() == currentPos) { + // the interval starts at the current position so no need for splitting + return false; + } + + // get current location + AllocatableValue currentLocation = currentInterval.location(); + assert currentLocation != null : "active intervals must have a location assigned!"; + + // get predecessor stuff + AbstractBlockBase predecessorBlock = currentBlock.getPredecessors()[0]; + int predEndId = allocator.getLastLirInstructionId(predecessorBlock); + Interval predecessorInterval = currentInterval.getIntervalCoveringOpId(predEndId); + assert predecessorInterval != null : "variable not live at the end of the only predecessor! " + predecessorBlock + " -> " + currentBlock + " interval: " + currentInterval; + AllocatableValue predecessorLocation = predecessorInterval.location(); + assert predecessorLocation != null : "handled intervals must have a location assigned!"; + + // END initialize and sanity checks + + if (currentLocation.equals(predecessorLocation)) { + // locations are already equal -> nothing to optimize + return false; + } + + if (!isStackSlotValue(predecessorLocation) && !isRegister(predecessorLocation)) { + assert predecessorInterval.canMaterialize(); + // value is materialized -> no need for optimization + return false; + } + + assert isStackSlotValue(currentLocation) || isRegister(currentLocation) : "current location not a register or stack slot " + currentLocation; + + try (Indent indent = Debug.logAndIndent("location differs: %s vs. %s", predecessorLocation, currentLocation)) { + // split current interval at current position + Debug.log("splitting at position %d", currentPos); + + assert allocator.isBlockBegin(currentPos) && ((currentPos & 1) == 0) : "split pos must be even when on block boundary"; + + Interval splitPart = currentInterval.split(currentPos, allocator); + activeLists.remove(binding, currentInterval); + + assert splitPart.from() >= currentPosition : "cannot append new interval before current walk position"; + + // the currentSplitChild is needed later when moves are inserted for reloading + assert splitPart.currentSplitChild() == currentInterval : "overwriting wrong currentSplitChild"; + splitPart.makeCurrentSplitChild(); + + if (Debug.isLogEnabled()) { + Debug.log("left interval : %s", currentInterval.logString(allocator)); + Debug.log("right interval : %s", splitPart.logString(allocator)); + } + + if (Options.LSRAOptSplitOnly.getValue()) { + // just add the split interval to the unhandled list + unhandledLists.addToListSortedByStartAndUsePositions(RegisterBinding.Any, splitPart); + } else { + if (isRegister(predecessorLocation)) { + splitRegisterInterval(splitPart, asRegister(predecessorLocation)); + } else { + assert isStackSlotValue(predecessorLocation); + Debug.log("assigning interval %s to %s", splitPart, predecessorLocation); + splitPart.assignLocation(predecessorLocation); + // activate interval + activeLists.addToListSortedByCurrentFromPositions(RegisterBinding.Stack, splitPart); + splitPart.state = State.Active; + + splitStackInterval(splitPart); + } + } + } + return true; + } + + @SuppressWarnings("try") + private void splitRegisterInterval(Interval interval, Register reg) { + // collect current usage of registers + initVarsForAlloc(interval); + initUseLists(false); + spillExcludeActiveFixed(); + // spillBlockUnhandledFixed(cur); + assert unhandledLists.get(RegisterBinding.Fixed) == Interval.EndMarker : "must not have unhandled fixed intervals because all fixed intervals have a use at position 0"; + spillBlockInactiveFixed(interval); + spillCollectActiveAny(RegisterPriority.LiveAtLoopEnd); + spillCollectInactiveAny(interval); + + if (Debug.isLogEnabled()) { + try (Indent indent2 = Debug.logAndIndent("state of registers:")) { + for (Register register : availableRegs) { + int i = register.number; + try (Indent indent3 = Debug.logAndIndent("reg %d: usePos: %d, blockPos: %d, intervals: ", i, usePos[i], blockPos[i])) { + for (int j = 0; j < spillIntervals[i].size(); j++) { + Debug.log("%d ", spillIntervals[i].get(j).operandNumber); + } + } + } + } + } + + // the register must be free at least until this position + boolean needSplit = blockPos[reg.number] <= interval.to(); + + int splitPos = blockPos[reg.number]; + + assert splitPos > 0 : "invalid splitPos"; + assert needSplit || splitPos > interval.from() : "splitting interval at from"; + + Debug.log("assigning interval %s to %s", interval, reg); + interval.assignLocation(reg.asValue(interval.kind())); + if (needSplit) { + // register not available for full interval : so split it + splitWhenPartialRegisterAvailable(interval, splitPos); + } + + // perform splitting and spilling for all affected intervals + splitAndSpillIntersectingIntervals(reg); + + // activate interval + activeLists.addToListSortedByCurrentFromPositions(RegisterBinding.Any, interval); + interval.state = State.Active; + + } +}