Optimize AOT's switchable calls for the monomorphic case.

runtime/vm/assembler_arm.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_ASSEMBLER_ARM_H_
 #define VM_ASSEMBLER_ARM_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm.h directly; use assembler.h instead.
 #endif
@@ skipping 350 matching lines @@
 };
 
 
 class Assembler : public ValueObject {
  public:
   explicit Assembler(bool use_far_branches = false)
       : buffer_(),
         prologue_offset_(-1),
         use_far_branches_(use_far_branches),
         comments_(),
-        constant_pool_allowed_(false) { }
+        constant_pool_allowed_(false) {
+    MonomorphicCheckedEntry();
+  }
 
   ~Assembler() { }
 
   void PopRegister(Register r) { Pop(r); }
 
   void Bind(Label* label);
   void Jump(Label* label) { b(label); }
 
   // Misc. functionality
   intptr_t CodeSize() const { return buffer_.Size(); }
@@ skipping 555 matching lines @@
   // Set up a Dart frame for a function compiled for on-stack replacement.
   // The frame layout is a normal Dart frame, but the frame is partially set
   // up on entry (it is the frame of the unoptimized code).
   void EnterOsrFrame(intptr_t extra_size);
 
   // Set up a stub frame so that the stack traversal code can easily identify
   // a stub frame.
   void EnterStubFrame();
   void LeaveStubFrame();
 
+  void NoMonomorphicCheckedEntry();
+  void MonomorphicCheckedEntry();
+
   // The register into which the allocation stats table is loaded with
   // LoadAllocationStatsAddress should be passed to
   // IncrementAllocationStats(WithSize) as stats_addr_reg to update the
   // allocation stats. These are separate assembler macros so we can
   // avoid a dependent load too nearby the load of the table address.
   void LoadAllocationStatsAddress(Register dest,
                                   intptr_t cid);
   void IncrementAllocationStats(Register stats_addr,
                                 intptr_t cid,
                                 Heap::Space space);
@@ skipping 210 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM_H_