Version 3.5.6.

src/mips/full-codegen-mips.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4034 matching lines @@
     __ Branch(if_false, ge, a1, Operand(FIRST_NONSTRING_TYPE));
     __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
     __ And(a1, a1, Operand(1 << Map::kIsUndetectable));
     Split(eq, a1, Operand(zero_reg),
           if_true, if_false, fall_through);
   } else if (check->Equals(isolate()->heap()->boolean_symbol())) {
     __ LoadRoot(at, Heap::kTrueValueRootIndex);
     __ Branch(if_true, eq, v0, Operand(at));
     __ LoadRoot(at, Heap::kFalseValueRootIndex);
     Split(eq, v0, Operand(at), if_true, if_false, fall_through);
+  } else if (FLAG_harmony_typeof &&
+             check->Equals(isolate()->heap()->null_symbol())) {
+    __ LoadRoot(at, Heap::kNullValueRootIndex);
+    Split(eq, v0, Operand(at), if_true, if_false, fall_through);
   } else if (check->Equals(isolate()->heap()->undefined_symbol())) {
     __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
     __ Branch(if_true, eq, v0, Operand(at));
     __ JumpIfSmi(v0, if_false);
     // Check for undetectable objects => true.
     __ lw(v0, FieldMemOperand(v0, HeapObject::kMapOffset));
     __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
     __ And(a1, a1, Operand(1 << Map::kIsUndetectable));
     Split(ne, a1, Operand(zero_reg), if_true, if_false, fall_through);
   } else if (check->Equals(isolate()->heap()->function_symbol())) {
     __ JumpIfSmi(v0, if_false);
     __ GetObjectType(v0, a1, v0);  // Leave map in a1.
     Split(ge, v0, Operand(FIRST_CALLABLE_SPEC_OBJECT_TYPE),
         if_true, if_false, fall_through);
 
   } else if (check->Equals(isolate()->heap()->object_symbol())) {
     __ JumpIfSmi(v0, if_false);
-    __ LoadRoot(at, Heap::kNullValueRootIndex);
-    __ Branch(if_true, eq, v0, Operand(at));
+    if (!FLAG_harmony_typeof) {
+      __ LoadRoot(at, Heap::kNullValueRootIndex);
+      __ Branch(if_true, eq, v0, Operand(at));
+    }
     // Check for JS objects => true.
     __ GetObjectType(v0, v0, a1);
     __ Branch(if_false, lt, a1, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
     __ lbu(a1, FieldMemOperand(v0, Map::kInstanceTypeOffset));
     __ Branch(if_false, gt, a1, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
     // Check for undetectable objects => false.
     __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
     __ And(a1, a1, Operand(1 << Map::kIsUndetectable));
     Split(eq, a1, Operand(zero_reg), if_true, if_false, fall_through);
   } else {
@@ skipping 228 matching lines @@
   __ Addu(at, a1, Operand(masm_->CodeObject()));
   __ Jump(at);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS