1 /* 2 * Copyright (c) 2015, 2015, 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 org.graalvm.compiler.core.common.alloc.RegisterAllocationConfig; 26 import org.graalvm.compiler.core.common.alloc.Trace; 27 import org.graalvm.compiler.core.common.alloc.TraceBuilderResult; 28 import org.graalvm.compiler.core.common.cfg.AbstractBlockBase; 29 import org.graalvm.compiler.debug.Debug; 30 import org.graalvm.compiler.debug.Debug.Scope; 31 import org.graalvm.compiler.debug.DebugCounter; 32 import org.graalvm.compiler.debug.Indent; 33 import org.graalvm.compiler.lir.LIR; 34 import org.graalvm.compiler.lir.LIRInstruction; 35 import org.graalvm.compiler.lir.alloc.trace.TraceAllocationPhase.TraceAllocationContext; 36 import org.graalvm.compiler.lir.gen.LIRGenerationResult; 37 import org.graalvm.compiler.lir.gen.LIRGeneratorTool.MoveFactory; 38 import org.graalvm.compiler.lir.phases.AllocationPhase; 39 import org.graalvm.compiler.lir.ssi.SSIUtil; 40 import org.graalvm.compiler.lir.ssi.SSIVerifier; 41 import org.graalvm.compiler.options.Option; 42 import org.graalvm.compiler.options.OptionType; 43 import org.graalvm.compiler.options.StableOptionValue; 44 45 import jdk.vm.ci.code.TargetDescription; 46 import jdk.vm.ci.meta.AllocatableValue; 47 48 /** 49 * Implements the Trace Register Allocation approach as described in 50 * <a href="http://dx.doi.org/10.1145/2972206.2972211">"Trace-based Register Allocation in a JIT 51 * Compiler"</a> by Josef Eisl et al. 52 */ 53 public final class TraceRegisterAllocationPhase extends AllocationPhase { 54 55 public static class Options { 56 // @formatter:off 57 @Option(help = "Use inter-trace register hints.", type = OptionType.Debug) 58 public static final StableOptionValue<Boolean> TraceRAuseInterTraceHints = new StableOptionValue<>(true); 59 @Option(help = "Share information about spilled values to other traces.", type = OptionType.Debug) 60 public static final StableOptionValue<Boolean> TraceRAshareSpillInformation = new StableOptionValue<>(true); 61 @Option(help = "Reuse spill slots for global move resolution cycle breaking.", type = OptionType.Debug) 62 public static final StableOptionValue<Boolean> TraceRAreuseStackSlotsForMoveResolutionCycleBreaking = new StableOptionValue<>(true); 63 @Option(help = "Cache stack slots globally (i.e. a variable always gets the same slot in every trace).", type = OptionType.Debug) 64 public static final StableOptionValue<Boolean> TraceRACacheStackSlots = new StableOptionValue<>(true); 65 // @formatter:on 66 } 67 68 private static final TraceGlobalMoveResolutionPhase TRACE_GLOBAL_MOVE_RESOLUTION_PHASE = new TraceGlobalMoveResolutionPhase(); 69 70 private static final DebugCounter tracesCounter = Debug.counter("TraceRA[traces]"); 71 72 public static final DebugCounter globalStackSlots = Debug.counter("TraceRA[GlobalStackSlots]"); 73 public static final DebugCounter allocatedStackSlots = Debug.counter("TraceRA[AllocatedStackSlots]"); 74 75 @Override 76 @SuppressWarnings("try") 77 protected void run(TargetDescription target, LIRGenerationResult lirGenRes, AllocationContext context) { 78 MoveFactory spillMoveFactory = context.spillMoveFactory; 79 RegisterAllocationConfig registerAllocationConfig = context.registerAllocationConfig; 80 LIR lir = lirGenRes.getLIR(); 81 assert SSIVerifier.verify(lir) : "LIR not in SSI form."; 82 TraceBuilderResult resultTraces = context.contextLookup(TraceBuilderResult.class); 83 84 TraceAllocationContext traceContext = new TraceAllocationContext(spillMoveFactory, registerAllocationConfig, resultTraces); 85 AllocatableValue[] cachedStackSlots = Options.TraceRACacheStackSlots.getValue() ? new AllocatableValue[lir.numVariables()] : null; 86 87 // currently this is not supported 88 boolean neverSpillConstant = false; 89 90 final TraceRegisterAllocationPolicy plan = DefaultTraceRegisterAllocationPolicy.allocationPolicy(target, lirGenRes, spillMoveFactory, registerAllocationConfig, cachedStackSlots, 91 resultTraces, neverSpillConstant); 92 93 Debug.dump(Debug.INFO_LOG_LEVEL, lir, "Before TraceRegisterAllocation"); 94 try (Scope s0 = Debug.scope("AllocateTraces", resultTraces)) { 95 for (Trace trace : resultTraces.getTraces()) { 96 tracesCounter.increment(); 97 TraceAllocationPhase<TraceAllocationContext> allocator = plan.selectStrategy(trace); 98 try (Indent i = Debug.logAndIndent("Allocating Trace%d: %s (%s)", trace.getId(), trace, allocator); Scope s = Debug.scope("AllocateTrace", trace)) { 99 allocator.apply(target, lirGenRes, trace, traceContext); 100 } 101 } 102 } catch (Throwable e) { 103 throw Debug.handle(e); 104 } 105 if (Debug.isDumpEnabled(Debug.INFO_LOG_LEVEL)) { 106 unnumberInstructions(lir); 107 Debug.dump(Debug.INFO_LOG_LEVEL, lir, "After trace allocation"); 108 } 109 110 TRACE_GLOBAL_MOVE_RESOLUTION_PHASE.apply(target, lirGenRes, traceContext); 111 deconstructSSIForm(lir); 112 } 113 114 /** 115 * Remove Phi/Sigma In/Out. 116 * 117 * Note: Incoming Values are needed for the RegisterVerifier, otherwise SIGMAs/PHIs where the 118 * Out and In value matches (ie. there is no resolution move) are falsely detected as errors. 119 */ 120 @SuppressWarnings("try") 121 private static void deconstructSSIForm(LIR lir) { 122 for (AbstractBlockBase<?> block : lir.getControlFlowGraph().getBlocks()) { 123 try (Indent i = Debug.logAndIndent("Fixup Block %s", block)) { 124 if (block.getPredecessorCount() != 0) { 125 SSIUtil.removeIncoming(lir, block); 126 } else { 127 assert lir.getControlFlowGraph().getStartBlock().equals(block); 128 } 129 SSIUtil.removeOutgoing(lir, block); 130 } 131 } 132 } 133 134 private static void unnumberInstructions(LIR lir) { 135 for (AbstractBlockBase<?> block : lir.getControlFlowGraph().getBlocks()) { 136 for (LIRInstruction op : lir.getLIRforBlock(block)) { 137 op.setId(-1); 138 } 139 } 140 } 141 }