[turbofan] The BytecodeGraphBuilder should never insert the empty frame state.

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 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/bytecode-graph-builder.h"
 
 #include "src/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 337 matching lines @@
 
   // Connect to the loop end.
   Node* terminate = builder()->graph()->NewNode(
       builder()->common()->Terminate(), effect, control);
   builder()->exit_controls_.push_back(terminate);
 }
 
 
 bool BytecodeGraphBuilder::Environment::StateValuesRequireUpdate(
     Node** state_values, int offset, int count) {
-  if (!builder()->deoptimization_enabled_) {
-    return false;
-  }
   if (*state_values == nullptr) {
     return true;
   }
   DCHECK_EQ((*state_values)->InputCount(), count);
   DCHECK_LE(static_cast<size_t>(offset + count), values()->size());
   Node** env_values = (count == 0) ? nullptr : &values()->at(offset);
   for (int i = 0; i < count; i++) {
     if ((*state_values)->InputAt(i) != env_values[i]) {
       return true;
     }
   }
   return false;
 }
 
 
 void BytecodeGraphBuilder::Environment::UpdateStateValues(Node** state_values,
                                                           int offset,
                                                           int count) {
   if (StateValuesRequireUpdate(state_values, offset, count)) {
     const Operator* op = common()->StateValues(count);
     (*state_values) = graph()->NewNode(op, count, &values()->at(offset));
   }
 }
 
 
 Node* BytecodeGraphBuilder::Environment::Checkpoint(
     BailoutId bailout_id, OutputFrameStateCombine combine) {
-  if (!builder()->deoptimization_enabled_) {
-    return builder()->jsgraph()->EmptyFrameState();
-  }
-
   // TODO(rmcilroy): Consider using StateValuesCache for some state values.
   UpdateStateValues(&parameters_state_values_, 0, parameter_count());
   UpdateStateValues(&registers_state_values_, register_base(),
                     register_count());
   UpdateStateValues(&accumulator_state_values_, accumulator_base(), 1);
 
   const Operator* op = common()->FrameState(
       bailout_id, combine, builder()->frame_state_function_info());
   Node* result = graph()->NewNode(
       op, parameters_state_values_, registers_state_values_,
@@ skipping 14 matching lines @@
         return false;
       }
     }
   }
   return true;
 }
 
 
 bool BytecodeGraphBuilder::Environment::StateValuesAreUpToDate(
     int output_poke_offset, int output_poke_count) {
-  if (!builder()->deoptimization_enabled_) return true;
   // Poke offset is relative to the top of the stack (i.e., the accumulator).
   int output_poke_start = accumulator_base() - output_poke_offset;
   int output_poke_end = output_poke_start + output_poke_count;
   return StateValuesAreUpToDate(&parameters_state_values_, 0, parameter_count(),
                                 output_poke_start, output_poke_end) &&
          StateValuesAreUpToDate(&registers_state_values_, register_base(),
                                 register_count(), output_poke_start,
                                 output_poke_end) &&
          StateValuesAreUpToDate(&accumulator_state_values_, accumulator_base(),
                                 1, output_poke_start, output_poke_end);
 }
 
 BytecodeGraphBuilder::BytecodeGraphBuilder(Zone* local_zone,
                                            CompilationInfo* info,
                                            JSGraph* jsgraph)
     : local_zone_(local_zone),
       jsgraph_(jsgraph),
       bytecode_array_(handle(info->shared_info()->bytecode_array())),
       exception_handler_table_(
           handle(HandlerTable::cast(bytecode_array()->handler_table()))),
       feedback_vector_(handle(info->shared_info()->feedback_vector())),
       frame_state_function_info_(common()->CreateFrameStateFunctionInfo(
           FrameStateType::kInterpretedFunction,
           bytecode_array()->parameter_count(),
           bytecode_array()->register_count(), info->shared_info())),
-      deoptimization_enabled_(info->is_deoptimization_enabled()),
       merge_environments_(local_zone),
       exception_handlers_(local_zone),
       current_exception_handler_(0),
       input_buffer_size_(0),
       input_buffer_(nullptr),
       exit_controls_(local_zone) {}
 
 Node* BytecodeGraphBuilder::GetNewTarget() {
   if (!new_target_.is_set()) {
     int params = bytecode_array()->parameter_count();
@@ skipping 1230 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8