[turbofan] Frame elision for code stubs

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index 802024e5644f6d2892ac73444eb9b08cbc21c6d3..215908770f71817a1edeef2a4664b7a6da382b90 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -1002,8 +1002,9 @@ struct OptimizeMovesPhase {
 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);
   }
 };
 
@@ -1373,11 +1374,7 @@ Handle<Code> Pipeline::ScheduleAndGenerateCode(
   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);
@@ -1485,12 +1482,6 @@ void Pipeline::AllocateRegisters(const RegisterConfiguration* config,
     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>();
@@ -1501,6 +1492,13 @@ void Pipeline::AllocateRegisters(const RegisterConfiguration* config,
     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()};