Mark maps having a hidden prototype rather than maps of hidden prototypes.

src/arm/builtins-arm.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_ARM
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 1447 matching lines @@
   __ CompareObjectType(type, ip, ip, FUNCTION_TEMPLATE_INFO_TYPE);
 
   // Otherwise load the parent function template and iterate.
   __ ldr(type,
          FieldMemOperand(type, FunctionTemplateInfo::kParentTemplateOffset),
          eq);
   __ b(&function_template_loop, eq);
 
   // Load the next prototype.
   __ bind(&next_prototype);
+  __ ldr(ip, FieldMemOperand(map, Map::kBitField3Offset));
+  __ tst(ip, Operand(Map::HasHiddenPrototype::kMask));
+  __ b(eq, receiver_check_failed);
   __ ldr(receiver, FieldMemOperand(map, Map::kPrototypeOffset));
-  // End if the prototype is null or not hidden.
-  __ CompareRoot(receiver, Heap::kNullValueRootIndex);
-  __ b(eq, receiver_check_failed);
   __ ldr(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
-  __ ldr(ip, FieldMemOperand(map, Map::kBitField3Offset));
-  __ tst(ip, Operand(Map::IsHiddenPrototype::kMask));
-  __ b(eq, receiver_check_failed);
   // Iterate.
   __ b(&prototype_loop_start);
 
   __ bind(&receiver_check_passed);
 }
 
 
 void Builtins::Generate_HandleFastApiCall(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0                 : number of arguments excluding receiver
@@ skipping 1200 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM