Use shorter write-barrier filtering sequence when value is known to be non-smi.

runtime/vm/assembler_ia32.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_IA32_H_
 #define VM_ASSEMBLER_IA32_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_ia32.h directly; use assembler.h instead.
 #endif
@@ skipping 593 matching lines @@
 
   void Drop(intptr_t stack_elements);
 
   void LoadObject(Register dst, const Object& object);
   void PushObject(const Object& object);
   void CompareObject(Register reg, const Object& object);
   void LoadDoubleConstant(XmmRegister dst, double value);
 
   void StoreIntoObject(Register object,  // Object we are storing into.
                        const Address& dest,  // Where we are storing into.
-                       Register value);  // Value we are storing.
+                       Register value,  // Value we are storing.
+                       bool can_value_be_smi = true);
 
   void StoreIntoObjectNoBarrier(Register object,
                                 const Address& dest,
                                 Register value);
   void StoreIntoObjectNoBarrier(Register object,
                                 const Address& dest,
                                 const Object& value);
 
   void TraceStoreIntoObject(Register object,
                             const Address& dest,
@@ skipping 158 matching lines @@
   void EmitComplex(int rm, const Operand& operand, const Immediate& immediate);
   void EmitLabel(Label* label, int instruction_size);
   void EmitLabelLink(Label* label);
   void EmitNearLabelLink(Label* label);
 
   void EmitGenericShift(int rm, Register reg, const Immediate& imm);
   void EmitGenericShift(int rm, const Operand& operand, Register shifter);
 
   void StoreIntoObjectFilter(Register object, Register value, Label* no_update);
 
+  // Shorter filtering sequence that assumes that value is not a smi.
+  void StoreIntoObjectFilterNoSmi(Register object,
+                                  Register value,
+                                  Label* no_update);
+
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 
 inline void Assembler::EmitUint8(uint8_t value) {
   buffer_.Emit<uint8_t>(value);
 }
 
 
@@ skipping 18 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_IA32_H_