Revert of [ignition/turbo] Perform liveness analysis on the bytecodes

src/compiler/bytecode-graph-builder.h

 // 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.
 
 #ifndef V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_
 #define V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_
 
 #include "src/compiler/bytecode-analysis.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/liveness-analyzer.h"
@@ skipping 117 matching lines @@
   // Prepare information for eager deoptimization. This information is carried
   // by dedicated {Checkpoint} nodes that are wired into the effect chain.
   // Conceptually this frame state is "before" a given operation.
   void PrepareEagerCheckpoint();
 
   // Prepare information for lazy deoptimization. This information is attached
   // to the given node and the output value produced by the node is combined.
   // Conceptually this frame state is "after" a given operation.
   void PrepareFrameState(Node* node, OutputFrameStateCombine combine);
 
+  // Computes register liveness and replaces dead ones in frame states with the
+  // undefined values.
+  void ClearNonLiveSlotsInFrameStates();
+
   void BuildCreateArguments(CreateArgumentsType type);
   Node* BuildLoadGlobal(Handle<Name> name, uint32_t feedback_slot_index,
                         TypeofMode typeof_mode);
   void BuildStoreGlobal(LanguageMode language_mode);
   void BuildNamedStore(LanguageMode language_mode);
   void BuildKeyedStore(LanguageMode language_mode);
   void BuildLdaLookupSlot(TypeofMode typeof_mode);
   void BuildLdaLookupContextSlot(TypeofMode typeof_mode);
   void BuildLdaLookupGlobalSlot(TypeofMode typeof_mode);
   void BuildStaLookupSlot(LanguageMode language_mode);
@@ skipping 101 matching lines @@
   }
 
   const BytecodeAnalysis* bytecode_analysis() const {
     return bytecode_analysis_;
   }
 
   void set_bytecode_analysis(const BytecodeAnalysis* bytecode_analysis) {
     bytecode_analysis_ = bytecode_analysis;
   }
 
+  LivenessAnalyzer* liveness_analyzer() { return &liveness_analyzer_; }
+
   bool IsLivenessAnalysisEnabled() const {
     return this->is_liveness_analysis_enabled_;
   }
 
 #define DECLARE_VISIT_BYTECODE(name, ...) void Visit##name();
   BYTECODE_LIST(DECLARE_VISIT_BYTECODE)
 #undef DECLARE_VISIT_BYTECODE
 
   Zone* local_zone_;
   JSGraph* jsgraph_;
@@ skipping 25 matching lines @@
   SetOncePointer<Node> function_closure_;
   SetOncePointer<Node> new_target_;
 
   // Control nodes that exit the function body.
   ZoneVector<Node*> exit_controls_;
 
   bool const is_liveness_analysis_enabled_;
 
   StateValuesCache state_values_cache_;
 
+  // Analyzer of register liveness.
+  LivenessAnalyzer liveness_analyzer_;
+
   // The Turbofan source position table, to be populated.
   SourcePositionTable* source_positions_;
 
   SourcePosition const start_position_;
 
   // Update [source_positions_]'s current position to that of the bytecode at
   // [offset], if any.
   void UpdateCurrentSourcePosition(SourcePositionTableIterator* it, int offset);
 
   static int const kBinaryOperationHintIndex = 1;
   static int const kCountOperationHintIndex = 0;
   static int const kBinaryOperationSmiHintIndex = 2;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeGraphBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_