[turbofan] Frame elision for code stubs

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 984 matching lines @@
   void Run(PipelineData* data, Zone* temp_zone) {
     MoveOptimizer move_optimizer(temp_zone, data->sequence());
     move_optimizer.Run();
   }
 };
 
 
 struct FrameElisionPhase {
   static const char* phase_name() { return "frame elision"; }
 
-  void Run(PipelineData* data, Zone* temp_zone) {
-    FrameElider(data->sequence()).Run();
+  void Run(PipelineData* data, Zone* temp_zone,
+           const CallDescriptor* descriptor) {
+    FrameElider(data->sequence()).Run(descriptor);
   }
 };
 
 
 struct JumpThreadingPhase {
   static const char* phase_name() { return "jump threading"; }
 
   void Run(PipelineData* data, Zone* temp_zone, bool frame_at_start) {
     ZoneVector<RpoNumber> result(temp_zone);
     if (JumpThreading::ComputeForwarding(temp_zone, result, data->sequence(),
@@ skipping 349 matching lines @@
       RegisterConfiguration::ArchDefault(RegisterConfiguration::TURBOFAN),
       call_descriptor, run_verifier);
   if (data->compilation_failed()) {
     info()->AbortOptimization(kNotEnoughVirtualRegistersRegalloc);
     return Handle<Code>();
   }
 
   BeginPhaseKind("code generation");
   // TODO(mtrofin): move this off to the register allocator.
   bool generate_frame_at_start =
-      !FLAG_turbo_frame_elision || !data_->info()->IsStub() ||
-      !data_->frame()->needs_frame() ||
-      data_->sequence()->instruction_blocks().front()->needs_frame() ||
-      linkage.GetIncomingDescriptor()->CalleeSavedFPRegisters() != 0 ||
-      linkage.GetIncomingDescriptor()->CalleeSavedRegisters() != 0;
+      data_->sequence()->instruction_blocks().front()->must_construct_frame();
   // Optimimize jumps.
   if (FLAG_turbo_jt) {
     Run<JumpThreadingPhase>(generate_frame_at_start);
   }
 
   // Generate final machine code.
   Run<GenerateCodePhase>(&linkage);
 
   Handle<Code> code = data->code();
   if (profiler_data != nullptr) {
@@ skipping 87 matching lines @@
     Run<AllocateDoubleRegistersPhase<GreedyAllocator>>();
   } else {
     Run<AllocateGeneralRegistersPhase<LinearScanAllocator>>();
     Run<AllocateDoubleRegistersPhase<LinearScanAllocator>>();
   }
 
   if (FLAG_turbo_preprocess_ranges) {
     Run<MergeSplintersPhase>();
   }
 
-  // We plan to enable frame elision only for stubs and bytecode handlers.
-  if (FLAG_turbo_frame_elision && info()->IsStub()) {
-    Run<LocateSpillSlotsPhase>();
-    Run<FrameElisionPhase>();
-  }
-
   Run<AssignSpillSlotsPhase>();
 
   Run<CommitAssignmentPhase>();
   Run<PopulateReferenceMapsPhase>();
   Run<ConnectRangesPhase>();
   Run<ResolveControlFlowPhase>();
   if (FLAG_turbo_move_optimization) {
     Run<OptimizeMovesPhase>();
   }
 
+  if (descriptor != nullptr && descriptor->RequiresFrameAsIncoming()) {
+    data_->sequence()->instruction_blocks()[0]->mark_needs_frame();
+  }
+
+  Run<LocateSpillSlotsPhase>();
+  Run<FrameElisionPhase>(descriptor);
+
   if (FLAG_trace_turbo_graph) {
     OFStream os(stdout);
     PrintableInstructionSequence printable = {config, data->sequence()};
     os << "----- Instruction sequence after register allocation -----\n"
        << printable;
   }
 
   if (verifier != nullptr) {
     verifier->VerifyAssignment();
     verifier->VerifyGapMoves();
   }
 
   if (FLAG_trace_turbo && !data->MayHaveUnverifiableGraph()) {
     TurboCfgFile tcf(data->isolate());
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 Isolate* Pipeline::isolate() const { return info()->isolate(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8