Reland: Introducing the LLVM greedy register allocator.

src/compiler/pipeline.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/pipeline.h"
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/base/platform/elapsed-timer.h"
@@ skipping 724 matching lines @@
 struct BuildLiveRangesPhase {
   static const char* phase_name() { return "build live ranges"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     LiveRangeBuilder builder(data->register_allocation_data());
     builder.BuildLiveRanges();
   }
 };
 
 
+template <typename RegAllocator>
 struct AllocateGeneralRegistersPhase {
   static const char* phase_name() { return "allocate general registers"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    LinearScanAllocator allocator(data->register_allocation_data(),
-                                  GENERAL_REGISTERS);
+    RegAllocator allocator(data->register_allocation_data(), GENERAL_REGISTERS);
     allocator.AllocateRegisters();
   }
 };
 
 
+template <typename RegAllocator>
 struct AllocateDoubleRegistersPhase {
   static const char* phase_name() { return "allocate double registers"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    LinearScanAllocator allocator(data->register_allocation_data(),
-                                  DOUBLE_REGISTERS);
+    RegAllocator allocator(data->register_allocation_data(), DOUBLE_REGISTERS);
     allocator.AllocateRegisters();
   }
 };
 
 
 struct AssignSpillSlotsPhase {
   static const char* phase_name() { return "assign spill slots"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     OperandAssigner assigner(data->register_allocation_data());
@@ skipping 490 matching lines @@
   Run<BuildLiveRangesPhase>();
   if (FLAG_trace_turbo_graph) {
     OFStream os(stdout);
     PrintableInstructionSequence printable = {config, data->sequence()};
     os << "----- Instruction sequence before register allocation -----\n"
        << printable;
   }
   if (verifier != nullptr) {
     CHECK(!data->register_allocation_data()->ExistsUseWithoutDefinition());
   }
-  Run<AllocateGeneralRegistersPhase>();
-  Run<AllocateDoubleRegistersPhase>();
+  if (FLAG_turbo_greedy_regalloc) {
+    Run<AllocateGeneralRegistersPhase<GreedyAllocator>>();
+    Run<AllocateDoubleRegistersPhase<GreedyAllocator>>();
+  } else {
+    Run<AllocateGeneralRegistersPhase<LinearScanAllocator>>();
+    Run<AllocateDoubleRegistersPhase<LinearScanAllocator>>();
+  }
   Run<AssignSpillSlotsPhase>();
 
   Run<CommitAssignmentPhase>();
   Run<PopulateReferenceMapsPhase>();
   Run<ConnectRangesPhase>();
   Run<ResolveControlFlowPhase>();
   if (FLAG_turbo_move_optimization) {
     Run<OptimizeMovesPhase>();
   }
 
@@ skipping 14 matching lines @@
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8