[turbofan] Deferred blocks splintering.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index a528cceea523644bdb575f61f76958bce3e6fdcd..3dbacc394f1b723d7477c8dc553f042a11a25279 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -35,6 +35,7 @@
 #include "src/compiler/js-type-feedback-lowering.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/jump-threading.h"
+#include "src/compiler/live-range-separator.h"
 #include "src/compiler/load-elimination.h"
 #include "src/compiler/loop-analysis.h"
 #include "src/compiler/loop-peeling.h"
@@ -42,7 +43,6 @@
 #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"
@@ -793,13 +793,13 @@ struct BuildLiveRangesPhase {
 };
 
 
-struct PreprocessLiveRangesPhase {
-  static const char* phase_name() { return "preprocess live ranges"; }
+struct SplinterLiveRangesPhase {
+  static const char* phase_name() { return "splinter live ranges"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    PreprocessLiveRanges live_range_preprocessor(
-        data->register_allocation_data(), temp_zone);
-    live_range_preprocessor.PreprocessRanges();
+    LiveRangeSeparator live_range_splinterer(data->register_allocation_data(),
+                                             temp_zone);
+    live_range_splinterer.Splinter();
   }
 };
 
@@ -828,6 +828,16 @@ struct AllocateDoubleRegistersPhase {
 };
 
 
+struct MergeSplintersPhase {
+  static const char* phase_name() { return "merge splintered ranges"; }
+  void Run(PipelineData* pipeline_data, Zone* temp_zone) {
+    RegisterAllocationData* data = pipeline_data->register_allocation_data();
+    LiveRangeMerger live_range_merger(data, temp_zone);
+    live_range_merger.Merge();
+  }
+};
+
+
 struct LocateSpillSlotsPhase {
   static const char* phase_name() { return "locate spill slots"; }
 
@@ -1338,14 +1348,14 @@ void Pipeline::AllocateRegisters(const RegisterConfiguration* config,
     CHECK(!data->register_allocation_data()->ExistsUseWithoutDefinition());
   }
 
-  if (FLAG_turbo_preprocess_ranges) {
-    Run<PreprocessLiveRangesPhase>();
-  }
+  Run<SplinterLiveRangesPhase>();
 
   // TODO(mtrofin): re-enable greedy once we have bots for range preprocessing.
   Run<AllocateGeneralRegistersPhase<LinearScanAllocator>>();
   Run<AllocateDoubleRegistersPhase<LinearScanAllocator>>();
 
+  Run<MergeSplintersPhase>();
+
   if (FLAG_turbo_frame_elision) {
     Run<LocateSpillSlotsPhase>();
     Run<FrameElisionPhase>();