1 /* 2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.graalvm.compiler.lir.alloc.trace; 24 25 import java.util.ArrayList; 26 27 import org.graalvm.compiler.core.common.alloc.RegisterAllocationConfig; 28 import org.graalvm.compiler.core.common.alloc.Trace; 29 import org.graalvm.compiler.core.common.alloc.TraceBuilderResult; 30 import org.graalvm.compiler.core.common.cfg.AbstractBlockBase; 31 import org.graalvm.compiler.lir.alloc.trace.TraceAllocationPhase.TraceAllocationContext; 32 import org.graalvm.compiler.lir.alloc.trace.TraceRegisterAllocationPolicy.AllocationStrategy; 33 import org.graalvm.compiler.lir.alloc.trace.bu.BottomUpAllocator; 34 import org.graalvm.compiler.lir.alloc.trace.lsra.TraceLinearScanPhase; 35 import org.graalvm.compiler.lir.gen.LIRGenerationResult; 36 import org.graalvm.compiler.lir.gen.LIRGeneratorTool.MoveFactory; 37 import org.graalvm.compiler.options.EnumOptionKey; 38 import org.graalvm.compiler.options.Option; 39 import org.graalvm.compiler.options.OptionKey; 40 import org.graalvm.compiler.options.OptionType; 41 import org.graalvm.compiler.options.OptionValues; 42 43 import jdk.vm.ci.code.TargetDescription; 44 import jdk.vm.ci.common.JVMCIError; 45 import jdk.vm.ci.meta.AllocatableValue; 46 47 /** 48 * Manages the selection of allocation strategies. 49 */ 50 public final class DefaultTraceRegisterAllocationPolicy { 51 52 public enum TraceRAPolicies { 53 Default, 54 LinearScanOnly, 55 BottomUpOnly 56 } 57 58 public static class Options { 59 // @formatter:off 60 @Option(help = "Use special allocator for trivial blocks.", type = OptionType.Debug) 61 public static final OptionKey<Boolean> TraceRAtrivialBlockAllocator = new OptionKey<>(true); 62 @Option(help = "Use LSRA / BottomUp ratio", type = OptionType.Debug) 63 public static final OptionKey<Double> TraceRAbottomUpRatio = new OptionKey<>(0.0); 64 @Option(help = "TraceRA allocation policy to use.", type = OptionType.Debug) 65 public static final EnumOptionKey<TraceRAPolicies> TraceRAPolicy = new EnumOptionKey<>(TraceRAPolicies.Default); 66 // @formatter:on 67 } 68 69 public static final class TrivialTraceStrategy extends AllocationStrategy { 70 71 public TrivialTraceStrategy(TraceRegisterAllocationPolicy plan) { 72 plan.super(); 73 } 74 75 @Override 76 public boolean shouldApplyTo(Trace trace) { 77 return TraceUtil.isTrivialTrace(getLIR(), trace); 78 } 79 80 @Override 81 protected TraceAllocationPhase<TraceAllocationContext> initAllocator(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, 82 RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant, 83 GlobalLivenessInfo livenessInfo, ArrayList<AllocationStrategy> strategies) { 84 return new TrivialTraceAllocator(); 85 } 86 } 87 88 public static class BottomUpStrategy extends AllocationStrategy { 89 90 public BottomUpStrategy(TraceRegisterAllocationPolicy plan) { 91 // explicitly specify the enclosing instance for the superclass constructor call 92 plan.super(); 93 } 94 95 @Override 96 public boolean shouldApplyTo(Trace trace) { 97 return !containsExceptionEdge(trace); 98 } 99 100 private static boolean containsExceptionEdge(Trace trace) { 101 for (AbstractBlockBase<?> block : trace.getBlocks()) { 102 // check if one of the successors is an exception handler 103 for (AbstractBlockBase<?> succ : block.getSuccessors()) { 104 if (succ.isExceptionEntry()) { 105 return true; 106 } 107 } 108 } 109 return false; 110 } 111 112 @Override 113 protected TraceAllocationPhase<TraceAllocationContext> initAllocator(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, 114 RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant, 115 GlobalLivenessInfo livenessInfo, ArrayList<AllocationStrategy> strategies) { 116 return new BottomUpAllocator(target, lirGenRes, spillMoveFactory, registerAllocationConfig, cachedStackSlots, resultTraces, neverSpillConstant, livenessInfo); 117 } 118 } 119 120 public static final class TraceLinearScanStrategy extends AllocationStrategy { 121 122 public TraceLinearScanStrategy(TraceRegisterAllocationPolicy plan) { 123 // explicitly specify the enclosing instance for the superclass constructor call 124 plan.super(); 125 } 126 127 @Override 128 public boolean shouldApplyTo(Trace trace) { 129 return true; 130 } 131 132 @Override 133 protected TraceAllocationPhase<TraceAllocationContext> initAllocator(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, 134 RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant, 135 GlobalLivenessInfo livenessInfo, ArrayList<AllocationStrategy> strategies) { 136 return new TraceLinearScanPhase(target, lirGenRes, spillMoveFactory, registerAllocationConfig, resultTraces, neverSpillConstant, cachedStackSlots, livenessInfo); 137 } 138 } 139 140 public static TraceRegisterAllocationPolicy allocationPolicy(TargetDescription target, LIRGenerationResult lirGenRes, MoveFactory spillMoveFactory, 141 RegisterAllocationConfig registerAllocationConfig, AllocatableValue[] cachedStackSlots, TraceBuilderResult resultTraces, boolean neverSpillConstant, 142 GlobalLivenessInfo livenessInfo, OptionValues options) { 143 TraceRegisterAllocationPolicy plan = new TraceRegisterAllocationPolicy(target, lirGenRes, spillMoveFactory, registerAllocationConfig, cachedStackSlots, resultTraces, neverSpillConstant, 144 livenessInfo); 145 if (Options.TraceRAtrivialBlockAllocator.getValue(options)) { 146 plan.appendStrategy(new TrivialTraceStrategy(plan)); 147 } 148 switch (Options.TraceRAPolicy.getValue(options)) { 149 case Default: 150 case LinearScanOnly: 151 plan.appendStrategy(new TraceLinearScanStrategy(plan)); 152 break; 153 case BottomUpOnly: 154 plan.appendStrategy(new BottomUpStrategy(plan)); 155 // Fallback 156 plan.appendStrategy(new TraceLinearScanStrategy(plan)); 157 break; 158 default: 159 throw JVMCIError.shouldNotReachHere(); 160 } 161 return plan; 162 } 163 }