[turbofan] Preprocessing live ranges before register allocation.

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/adapters.h"
@@ skipping 24 matching lines @@
 #include "src/compiler/js-type-feedback-lowering.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/jump-threading.h"
 #include "src/compiler/load-elimination.h"
 #include "src/compiler/loop-analysis.h"
 #include "src/compiler/loop-peeling.h"
 #include "src/compiler/machine-operator-reducer.h"
 #include "src/compiler/move-optimizer.h"
 #include "src/compiler/osr.h"
 #include "src/compiler/pipeline-statistics.h"
+#include "src/compiler/preprocess-live-ranges.h"
 #include "src/compiler/register-allocator.h"
 #include "src/compiler/register-allocator-verifier.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/scheduler.h"
 #include "src/compiler/select-lowering.h"
 #include "src/compiler/simplified-lowering.h"
 #include "src/compiler/simplified-operator-reducer.h"
 #include "src/compiler/tail-call-optimization.h"
 #include "src/compiler/typer.h"
 #include "src/compiler/value-numbering-reducer.h"
@@ skipping 723 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(), temp_zone);
     builder.BuildLiveRanges();
   }
 };
 
 
+struct PreprocessLiveRangesPhase {
+  static const char* phase_name() { return "preprocess live ranges"; }
+
+  void Run(PipelineData* data, Zone* temp_zone) {
+    PreprocessLiveRanges live_range_preprocessor(
+        data->register_allocation_data(), temp_zone);
+    live_range_preprocessor.PreprocessRanges();
+  }
+};
+
+
 template <typename RegAllocator>
 struct AllocateGeneralRegistersPhase {
   static const char* phase_name() { return "allocate general registers"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     RegAllocator allocator(data->register_allocation_data(), GENERAL_REGISTERS,
                            temp_zone);
     allocator.AllocateRegisters();
   }
 };
@@ skipping 515 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());
   }
+
+  if (FLAG_turbo_preprocess_ranges) {
+    Run<PreprocessLiveRangesPhase>();
+  }
+
   if (FLAG_turbo_greedy_regalloc) {
     Run<AllocateGeneralRegistersPhase<GreedyAllocator>>();
     Run<AllocateDoubleRegistersPhase<GreedyAllocator>>();
   } else {
     Run<AllocateGeneralRegistersPhase<LinearScanAllocator>>();
     Run<AllocateDoubleRegistersPhase<LinearScanAllocator>>();
   }
 
   if (FLAG_turbo_frame_elision) {
     Run<LocateSpillSlotsPhase>();
@@ skipping 27 matching lines @@
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8