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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
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 * 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.
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package org.graalvm.compiler.lir.alloc.trace;

import java.util.ArrayList;

import org.graalvm.compiler.core.common.alloc.RegisterAllocationConfig;
import org.graalvm.compiler.core.common.alloc.Trace;
import org.graalvm.compiler.core.common.alloc.TraceBuilderResult;
import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
import org.graalvm.compiler.lir.alloc.trace.TraceAllocationPhase.TraceAllocationContext;
import org.graalvm.compiler.lir.alloc.trace.TraceRegisterAllocationPolicy.AllocationStrategy;
import org.graalvm.compiler.lir.alloc.trace.bu.BottomUpAllocator;
import org.graalvm.compiler.lir.alloc.trace.lsra.TraceLinearScanPhase;
import org.graalvm.compiler.lir.gen.LIRGenerationResult;
import org.graalvm.compiler.lir.gen.LIRGeneratorTool.MoveFactory;
import org.graalvm.compiler.options.EnumOptionValue;
import org.graalvm.compiler.options.Option;
import org.graalvm.compiler.options.OptionType;
import org.graalvm.compiler.options.StableOptionValue;

import jdk.vm.ci.code.TargetDescription;
import jdk.vm.ci.common.JVMCIError;
import jdk.vm.ci.meta.AllocatableValue;

Manages the selection of allocation strategies.
/** * Manages the selection of allocation strategies. */
public final class DefaultTraceRegisterAllocationPolicy { public enum TraceRAPolicies { Default, LinearScanOnly, BottomUpOnly } public static class Options { // @formatter:off @Option(help = "Use special allocator for trivial blocks.", type = OptionType.Debug) public static final StableOptionValue<Boolean> TraceRAtrivialBlockAllocator = new StableOptionValue<>(true); @Option(help = "Use LSRA / BottomUp ratio", type = OptionType.Debug) public static final StableOptionValue<Double> TraceRAbottomUpRatio = new StableOptionValue<>(0.0); @Option(help = "TraceRA allocation policy to use.", type = OptionType.Debug) public static final EnumOptionValue<TraceRAPolicies> TraceRAPolicy = new EnumOptionValue<>(TraceRAPolicies.Default); // @formatter:on } public static final class TrivialTraceStrategy extends AllocationStrategy { public TrivialTraceStrategy(TraceRegisterAllocationPolicy plan) { plan.super(); } @Override public boolean shouldApplyTo(Trace trace) { return TraceUtil.isTrivialTrace(getLIR(), trace); } @Override protected TraceAllocationPhase<TraceAllocationContext> initAllocator(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant, ArrayList<AllocationStrategy> strategies) { return new TrivialTraceAllocator(); } } public static class BottomUpStrategy extends AllocationStrategy { public BottomUpStrategy(TraceRegisterAllocationPolicy plan) { // explicitly specify the enclosing instance for the superclass constructor call plan.super(); } @Override public boolean shouldApplyTo(Trace trace) { return !containsExceptionEdge(trace); } private static boolean containsExceptionEdge(Trace trace) { for (AbstractBlockBase<?> block : trace.getBlocks()) { // check if one of the successors is an exception handler for (AbstractBlockBase<?> succ : block.getSuccessors()) { if (succ.isExceptionEntry()) { return true; } } } return false; } @Override protected TraceAllocationPhase<TraceAllocationContext> initAllocator(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant, ArrayList<AllocationStrategy> strategies) { return new BottomUpAllocator(target, lirGenRes, spillMoveFactory, registerAllocationConfig, cachedStackSlots, resultTraces, neverSpillConstant); } } public static final class TraceLinearScanStrategy extends AllocationStrategy { public TraceLinearScanStrategy(TraceRegisterAllocationPolicy plan) { // explicitly specify the enclosing instance for the superclass constructor call plan.super(); } @Override public boolean shouldApplyTo(Trace trace) { return true; } @Override protected TraceAllocationPhase<TraceAllocationContext> initAllocator(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant, ArrayList<AllocationStrategy> strategies) { return new TraceLinearScanPhase(target, lirGenRes, spillMoveFactory, registerAllocationConfig, resultTraces, neverSpillConstant, cachedStackSlots); } } public static TraceRegisterAllocationPolicy allocationPolicy(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant) { TraceRegisterAllocationPolicy plan = new TraceRegisterAllocationPolicy(target, lirGenRes, spillMoveFactory, registerAllocationConfig, cachedStackSlots, resultTraces, neverSpillConstant); if (Options.TraceRAtrivialBlockAllocator.getValue()) { plan.appendStrategy(new TrivialTraceStrategy(plan)); } switch (Options.TraceRAPolicy.getValue()) { case Default: case LinearScanOnly: plan.appendStrategy(new TraceLinearScanStrategy(plan)); break; case BottomUpOnly: plan.appendStrategy(new BottomUpStrategy(plan)); // Fallback plan.appendStrategy(new TraceLinearScanStrategy(plan)); break; default: throw JVMCIError.shouldNotReachHere(); } return plan; } }