Merge TRUNCDIV and MOD into one instruction. Icorporated feedback from CL https://codereview.chromi…

runtime/vm/flow_graph_optimizer.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_OPTIMIZER_H_
 #define VM_FLOW_GRAPH_OPTIMIZER_H_
 
 #include "vm/intermediate_language.h"
 #include "vm/flow_graph.h"
 
@@ skipping 13 matching lines @@
   FlowGraph* flow_graph() const { return flow_graph_; }
 
   // Use ICData to optimize, replace or eliminate instructions.
   void ApplyICData();
 
   // Use propagated class ids to optimize, replace or eliminate instructions.
   void ApplyClassIds();
 
   // 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.
-  void TryOptimizeLeftShiftWithBitAndPattern();
+  // Merge instructions.
+  void TryOptimizePatterns();
 
   // Returns true if any instructions were canonicalized away.
   bool Canonicalize();
 
   void EliminateDeadPhis();
 
   void SelectRepresentations();
 
   void InferSmiRanges();
 
@@ skipping 151 matching lines @@
 
   RawBool* InstanceOfAsBool(const ICData& ic_data,
                             const AbstractType& type) const;
 
   void ReplaceWithMathCFunction(InstanceCallInstr* call,
                                 MethodRecognizer::Kind recognized_kind);
 
   void OptimizeLeftShiftBitAndSmiOp(Definition* bit_and_instr,
                                     Definition* left_instr,
                                     Definition* right_instr);
+  void TryMergeTruncDivMod(GrowableArray<BinarySmiOpInstr*>* merge_candidates);
 
   FlowGraph* flow_graph_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphOptimizer);
 };
 
 
 // Loop invariant code motion.
 class LICM : public ValueObject {
  public:
@@ skipping 165 matching lines @@
 // Optimize spill stores inside try-blocks by identifying values that always
 // contain a single known constant at catch block entry.
 class TryCatchAnalyzer : public AllStatic {
  public:
   static void Optimize(FlowGraph* flow_graph);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_OPTIMIZER_H_