Skeleton of a linear scan register allocator.

runtime/vm/flow_graph_compiler_x64.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_FLOW_GRAPH_COMPILER_X64_H_
 #define VM_FLOW_GRAPH_COMPILER_X64_H_
 
 #ifndef VM_FLOW_GRAPH_COMPILER_H_
 #error Include flow_graph_compiler.h instead of flow_graph_compiler_x64.h.
 #endif
@@ skipping 11 matching lines @@
    public:
     BlockInfo() : label() { }
     Label label;
   };
 
  public:
   FlowGraphCompiler(Assembler* assembler,
                     const ParsedFunction& parsed_function,
                     const GrowableArray<BlockEntryInstr*>& block_order,
                     bool is_optimizing,
+                    bool is_ssa,
                     bool is_leaf);
 
   ~FlowGraphCompiler();
 
   // Accessors.
   Assembler* assembler() const { return assembler_; }
   const ParsedFunction& parsed_function() const { return parsed_function_; }
   const GrowableArray<BlockEntryInstr*>& block_order() const {
     return block_order_;
   }
@@ skipping 233 matching lines @@
   // Compiler specific per-block state.  Indexed by postorder block number
   // for convenience.  This is not the block's index in the block order,
   // which is reverse postorder.
   BlockEntryInstr* current_block_;
   ExceptionHandlerList* exception_handlers_list_;
   DescriptorList* pc_descriptors_list_;
   StackmapBuilder* stackmap_builder_;
   GrowableArray<BlockInfo*> block_info_;
   GrowableArray<DeoptimizationStub*> deopt_stubs_;
   const bool is_optimizing_;
+  const bool is_ssa_;
   const bool is_dart_leaf_;
 
   const Bool& bool_true_;
   const Bool& bool_false_;
   const Class& double_class_;
 
   FrameRegisterAllocator frame_register_allocator_;
+  ParallelMoveResolver parallel_move_resolver_;
+
+  // Currently instructions generate deopt stubs internally by
+  // calling AddDeoptStub.  To communicate deoptimization environment
+  // that should be used when deoptimizing we store it in this variable.
+  // In future AddDeoptStub should be moved out of the instruction template.
+  Environment* pending_deoptimization_env_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphCompiler);
 };
 
 
 class DeoptimizationStub : public ZoneAllocated {
  public:
   DeoptimizationStub(intptr_t deopt_id,
                      intptr_t deopt_token_pos,
                      intptr_t try_index,
                      DeoptReasonId reason)
       : deopt_id_(deopt_id),
         deopt_token_pos_(deopt_token_pos),
         try_index_(try_index),
         reason_(reason),
         registers_(2),
+        deoptimization_env_(NULL),
         entry_label_() {}
 
   void Push(Register reg) { registers_.Add(reg); }
   Label* entry_label() { return &entry_label_; }
 
   // Implementation is in architecture specific file.
   void GenerateCode(FlowGraphCompiler* compiler);
 
+  void set_deoptimization_env(Environment* env) {
+    deoptimization_env_ = env;
+  }
+
  private:
   const intptr_t deopt_id_;
   const intptr_t deopt_token_pos_;
   const intptr_t try_index_;
   const DeoptReasonId reason_;
   GrowableArray<Register> registers_;
+  const Environment* deoptimization_env_;
   Label entry_label_;
 
   DISALLOW_COPY_AND_ASSIGN(DeoptimizationStub);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_COMPILER_X64_H_