Use a dictionary-mode code cache on the map rather than a dual system.

src/ia32/code-stubs-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 3839 matching lines @@
   __ bind(&try_array);
   __ CompareRoot(FieldOperand(scratch, 0), Heap::kFixedArrayMapRootIndex);
   __ j(not_equal, &not_array);
   HandleArrayCases(masm, receiver, name, vector, slot, scratch, true, &miss);
 
   __ bind(&not_array);
   __ CompareRoot(scratch, Heap::kmegamorphic_symbolRootIndex);
   __ j(not_equal, &miss);
   __ push(slot);
   __ push(vector);
-  Code::Flags code_flags = Code::RemoveTypeAndHolderFromFlags(
-      Code::ComputeHandlerFlags(Code::LOAD_IC));
+  Code::Flags code_flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::LOAD_IC));
   masm->isolate()->stub_cache()->GenerateProbe(masm, Code::LOAD_IC, code_flags,
                                                receiver, name, vector, scratch);
   __ pop(vector);
   __ pop(slot);
 
   __ bind(&miss);
   LoadIC::GenerateMiss(masm);
 }
 
 
@@ skipping 239 matching lines @@
   HandlePolymorphicStoreCase(masm, receiver, key, vector, slot, scratch, true,
                              &miss);
 
   __ bind(&not_array);
   __ CompareRoot(scratch, Heap::kmegamorphic_symbolRootIndex);
   __ j(not_equal, &miss);
 
   __ pop(value);
   __ push(slot);
   __ push(vector);
-  Code::Flags code_flags = Code::RemoveTypeAndHolderFromFlags(
-      Code::ComputeHandlerFlags(Code::STORE_IC));
+  Code::Flags code_flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::STORE_IC));
   masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, code_flags,
                                                receiver, key, slot, no_reg);
   __ pop(vector);
   __ pop(slot);
   Label no_pop_miss;
   __ jmp(&no_pop_miss);
 
   __ bind(&miss);
   __ pop(value);
   __ bind(&no_pop_miss);
@@ skipping 1706 matching lines @@
                            return_value_operand, NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32