VM: Remove more duplicate code between AOT and JIT compiler.

runtime/vm/flow_graph.h

 // Copyright (c) 2013, 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_H_
 #define VM_FLOW_GRAPH_H_
 
 #include "vm/bit_vector.h"
 #include "vm/growable_array.h"
 #include "vm/hash_map.h"
@@ skipping 287 matching lines @@
 
   void SelectRepresentations();
 
   void WidenSmiToInt32();
 
   // Remove environments from the instructions which do not deoptimize.
   void EliminateEnvironments();
 
   bool IsReceiver(Definition* def) const;
 
+  // Optimize (a << b) & c pattern: if c is a positive Smi or zero, then the
+  // shift can be a truncating Smi shift-left and result is always Smi.
+  // Merge instructions (only per basic-block).
+  void TryOptimizePatterns();
+
  private:
   friend class IfConverter;
   friend class BranchSimplifier;
   friend class ConstantPropagator;
   friend class DeadCodeElimination;
 
   // SSA transformation methods and fields.
   void ComputeDominators(GrowableArray<BitVector*>* dominance_frontier);
 
   void CompressPath(
@@ skipping 36 matching lines @@
   void ConvertEnvironmentUse(Value* use, Representation from);
   void InsertConversion(Representation from,
                         Representation to,
                         Value* use,
                         bool is_environment_use);
 
   void ComputeIsReceiver(PhiInstr* phi) const;
   void ComputeIsReceiverRecursive(PhiInstr* phi,
                                   GrowableArray<PhiInstr*>* unmark) const;
 
+  void OptimizeLeftShiftBitAndSmiOp(
+      ForwardInstructionIterator* current_iterator,
+      Definition* bit_and_instr,
+      Definition* left_instr,
+      Definition* right_instr);
+
+  void TryMergeTruncDivMod(GrowableArray<BinarySmiOpInstr*>* merge_candidates);
+  void TryMergeMathUnary(GrowableArray<MathUnaryInstr*>* merge_candidates);
+
+  void AppendExtractNthOutputForMerged(Definition* instr, intptr_t ix,
+                                       Representation rep, intptr_t cid);
+
   Thread* thread_;
 
   // DiscoverBlocks computes parent_ and assigned_vars_ which are then used
   // if/when computing SSA.
   GrowableArray<intptr_t> parent_;
   GrowableArray<BitVector*> assigned_vars_;
 
   intptr_t current_ssa_temp_index_;
   intptr_t max_block_id_;
 
@@ skipping 168 matching lines @@
 
  private:
   GrowableArray<Definition*> defs_;
   BitVector* contains_vector_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_H_