Experimental parser: merge r19949

src/mips/code-stubs-mips.cc

 // Copyright 2012 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 148 matching lines @@
 void KeyedLoadFieldStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { a1 };
   descriptor->register_param_count_ = 1;
   descriptor->register_params_ = registers;
   descriptor->deoptimization_handler_ = NULL;
 }
 
 
+void StringLengthStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { a0, a2 };
+  descriptor->register_param_count_ = 2;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ = NULL;
+}
+
+
+void KeyedStringLengthStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { a1, a0 };
+  descriptor->register_param_count_ = 2;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ = NULL;
+}
+
+
 void KeyedStoreFastElementStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { a2, a1, a0 };
   descriptor->register_param_count_ = 3;
   descriptor->register_params_ = registers;
   descriptor->deoptimization_handler_ =
       FUNCTION_ADDR(KeyedStoreIC_MissFromStubFailure);
 }
 
@@ skipping 2018 matching lines @@
     receiver = a0;
   }
 
   StubCompiler::GenerateLoadFunctionPrototype(masm, receiver, a3, t0, &miss);
   __ bind(&miss);
   StubCompiler::TailCallBuiltin(
       masm, BaseLoadStoreStubCompiler::MissBuiltin(kind()));
 }
 
 
-void StringLengthStub::Generate(MacroAssembler* masm) {
-  Label miss;
-  Register receiver;
-  if (kind() == Code::KEYED_LOAD_IC) {
-    // ----------- S t a t e -------------
-    //  -- ra    : return address
-    //  -- a0    : key
-    //  -- a1    : receiver
-    // -----------------------------------
-    __ Branch(&miss, ne, a0,
-        Operand(masm->isolate()->factory()->length_string()));
-    receiver = a1;
-  } else {
-    ASSERT(kind() == Code::LOAD_IC);
-    // ----------- S t a t e -------------
-    //  -- a2    : name
-    //  -- ra    : return address
-    //  -- a0    : receiver
-    //  -- sp[0] : receiver
-    // -----------------------------------
-    receiver = a0;
-  }
-
-  StubCompiler::GenerateLoadStringLength(masm, receiver, a3, t0, &miss);
-
-  __ bind(&miss);
-  StubCompiler::TailCallBuiltin(
-      masm, BaseLoadStoreStubCompiler::MissBuiltin(kind()));
-}
-
-
 void StoreArrayLengthStub::Generate(MacroAssembler* masm) {
   // This accepts as a receiver anything JSArray::SetElementsLength accepts
   // (currently anything except for external arrays which means anything with
   // elements of FixedArray type).  Value must be a number, but only smis are
   // accepted as the most common case.
   Label miss;
 
   Register receiver;
   Register value;
   if (kind() == Code::KEYED_STORE_IC) {
@@ skipping 110 matching lines @@
   __ lw(v0, MemOperand(a3, kDisplacement));
 
   // Slow-case: Handle non-smi or out-of-bounds access to arguments
   // by calling the runtime system.
   __ bind(&slow);
   __ push(a1);
   __ TailCallRuntime(Runtime::kGetArgumentsProperty, 1, 1);
 }
 
 
-void ArgumentsAccessStub::GenerateNewNonStrictSlow(MacroAssembler* masm) {
+void ArgumentsAccessStub::GenerateNewSloppySlow(MacroAssembler* masm) {
   // sp[0] : number of parameters
   // sp[4] : receiver displacement
   // sp[8] : function
   // Check if the calling frame is an arguments adaptor frame.
   Label runtime;
   __ lw(a3, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   __ lw(a2, MemOperand(a3, StandardFrameConstants::kContextOffset));
   __ Branch(&runtime,
             ne,
             a2,
             Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
 
   // Patch the arguments.length and the parameters pointer in the current frame.
   __ lw(a2, MemOperand(a3, ArgumentsAdaptorFrameConstants::kLengthOffset));
   __ sw(a2, MemOperand(sp, 0 * kPointerSize));
   __ sll(t3, a2, 1);
   __ Addu(a3, a3, Operand(t3));
   __ addiu(a3, a3, StandardFrameConstants::kCallerSPOffset);
   __ sw(a3, MemOperand(sp, 1 * kPointerSize));
 
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kNewArgumentsFast, 3, 1);
 }
 
 
-void ArgumentsAccessStub::GenerateNewNonStrictFast(MacroAssembler* masm) {
+void ArgumentsAccessStub::GenerateNewSloppyFast(MacroAssembler* masm) {
   // Stack layout:
   //  sp[0] : number of parameters (tagged)
   //  sp[4] : address of receiver argument
   //  sp[8] : function
   // Registers used over whole function:
   //  t2 : allocated object (tagged)
   //  t5 : mapped parameter count (tagged)
 
   __ lw(a1, MemOperand(sp, 0 * kPointerSize));
   // a1 = parameter count (tagged)
@@ skipping 43 matching lines @@
   __ sll(t5, a1, 1);
   __ addiu(t5, t5, kParameterMapHeaderSize);
   __ bind(&param_map_size);
 
   // 2. Backing store.
   __ sll(t6, a2, 1);
   __ Addu(t5, t5, Operand(t6));
   __ Addu(t5, t5, Operand(FixedArray::kHeaderSize));
 
   // 3. Arguments object.
-  __ Addu(t5, t5, Operand(Heap::kArgumentsObjectSize));
+  __ Addu(t5, t5, Operand(Heap::kSloppyArgumentsObjectSize));
 
   // Do the allocation of all three objects in one go.
   __ Allocate(t5, v0, a3, t0, &runtime, TAG_OBJECT);
 
   // v0 = address of new object(s) (tagged)
   // a2 = argument count (tagged)
   // Get the arguments boilerplate from the current native context into t0.
   const int kNormalOffset =
-      Context::SlotOffset(Context::ARGUMENTS_BOILERPLATE_INDEX);
+      Context::SlotOffset(Context::SLOPPY_ARGUMENTS_BOILERPLATE_INDEX);
   const int kAliasedOffset =
       Context::SlotOffset(Context::ALIASED_ARGUMENTS_BOILERPLATE_INDEX);
 
   __ lw(t0, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
   __ lw(t0, FieldMemOperand(t0, GlobalObject::kNativeContextOffset));
   Label skip2_ne, skip2_eq;
   __ Branch(&skip2_ne, ne, a1, Operand(zero_reg));
   __ lw(t0, MemOperand(t0, kNormalOffset));
   __ bind(&skip2_ne);
 
@@ skipping 20 matching lines @@
 
   // Use the length (smi tagged) and set that as an in-object property too.
   STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
   const int kLengthOffset = JSObject::kHeaderSize +
       Heap::kArgumentsLengthIndex * kPointerSize;
   __ sw(a2, FieldMemOperand(v0, kLengthOffset));
 
   // Set up the elements pointer in the allocated arguments object.
   // If we allocated a parameter map, t0 will point there, otherwise
   // it will point to the backing store.
-  __ Addu(t0, v0, Operand(Heap::kArgumentsObjectSize));
+  __ Addu(t0, v0, Operand(Heap::kSloppyArgumentsObjectSize));
   __ sw(t0, FieldMemOperand(v0, JSObject::kElementsOffset));
 
   // v0 = address of new object (tagged)
   // a1 = mapped parameter count (tagged)
   // a2 = argument count (tagged)
   // t0 = address of parameter map or backing store (tagged)
   // Initialize parameter map. If there are no mapped arguments, we're done.
   Label skip_parameter_map;
   Label skip3;
   __ Branch(&skip3, ne, a1, Operand(Smi::FromInt(0)));
   // Move backing store address to a3, because it is
   // expected there when filling in the unmapped arguments.
   __ mov(a3, t0);
   __ bind(&skip3);
 
   __ Branch(&skip_parameter_map, eq, a1, Operand(Smi::FromInt(0)));
 
-  __ LoadRoot(t2, Heap::kNonStrictArgumentsElementsMapRootIndex);
+  __ LoadRoot(t2, Heap::kSloppyArgumentsElementsMapRootIndex);
   __ sw(t2, FieldMemOperand(t0, FixedArray::kMapOffset));
   __ Addu(t2, a1, Operand(Smi::FromInt(2)));
   __ sw(t2, FieldMemOperand(t0, FixedArray::kLengthOffset));
   __ sw(cp, FieldMemOperand(t0, FixedArray::kHeaderSize + 0 * kPointerSize));
   __ sll(t6, a1, 1);
   __ Addu(t2, t0, Operand(t6));
   __ Addu(t2, t2, Operand(kParameterMapHeaderSize));
   __ sw(t2, FieldMemOperand(t0, FixedArray::kHeaderSize + 1 * kPointerSize));
 
   // Copy the parameter slots and the holes in the arguments.
@@ skipping 102 matching lines @@
 
   // Try the new space allocation. Start out with computing the size
   // of the arguments object and the elements array in words.
   Label add_arguments_object;
   __ bind(&try_allocate);
   __ Branch(&add_arguments_object, eq, a1, Operand(zero_reg));
   __ srl(a1, a1, kSmiTagSize);
 
   __ Addu(a1, a1, Operand(FixedArray::kHeaderSize / kPointerSize));
   __ bind(&add_arguments_object);
-  __ Addu(a1, a1, Operand(Heap::kArgumentsObjectSizeStrict / kPointerSize));
+  __ Addu(a1, a1, Operand(Heap::kStrictArgumentsObjectSize / kPointerSize));
 
   // Do the allocation of both objects in one go.
   __ Allocate(a1, v0, a2, a3, &runtime,
               static_cast<AllocationFlags>(TAG_OBJECT | SIZE_IN_WORDS));
 
   // Get the arguments boilerplate from the current native context.
   __ lw(t0, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
   __ lw(t0, FieldMemOperand(t0, GlobalObject::kNativeContextOffset));
   __ lw(t0, MemOperand(t0, Context::SlotOffset(
-      Context::STRICT_MODE_ARGUMENTS_BOILERPLATE_INDEX)));
+      Context::STRICT_ARGUMENTS_BOILERPLATE_INDEX)));
 
   // Copy the JS object part.
   __ CopyFields(v0, t0, a3.bit(), JSObject::kHeaderSize / kPointerSize);
 
   // Get the length (smi tagged) and set that as an in-object property too.
   STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
   __ lw(a1, MemOperand(sp, 0 * kPointerSize));
   __ sw(a1, FieldMemOperand(v0, JSObject::kHeaderSize +
       Heap::kArgumentsLengthIndex * kPointerSize));
 
   Label done;
   __ Branch(&done, eq, a1, Operand(zero_reg));
 
   // Get the parameters pointer from the stack.
   __ lw(a2, MemOperand(sp, 1 * kPointerSize));
 
   // Set up the elements pointer in the allocated arguments object and
   // initialize the header in the elements fixed array.
-  __ Addu(t0, v0, Operand(Heap::kArgumentsObjectSizeStrict));
+  __ Addu(t0, v0, Operand(Heap::kStrictArgumentsObjectSize));
   __ sw(t0, FieldMemOperand(v0, JSObject::kElementsOffset));
   __ LoadRoot(a3, Heap::kFixedArrayMapRootIndex);
   __ sw(a3, FieldMemOperand(t0, FixedArray::kMapOffset));
   __ sw(a1, FieldMemOperand(t0, FixedArray::kLengthOffset));
   // Untag the length for the loop.
   __ srl(a1, a1, kSmiTagSize);
 
   // Copy the fixed array slots.
   Label loop;
   // Set up t0 to point to the first array slot.
@@ skipping 466 matching lines @@
   // Cache the called function in a feedback vector slot.  Cache states
   // are uninitialized, monomorphic (indicated by a JSFunction), and
   // megamorphic.
   // a0 : number of arguments to the construct function
   // a1 : the function to call
   // a2 : Feedback vector
   // a3 : slot in feedback vector (Smi)
   Label initialize, done, miss, megamorphic, not_array_function;
 
   ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
-            masm->isolate()->heap()->undefined_value());
+            masm->isolate()->heap()->megamorphic_symbol());
   ASSERT_EQ(*TypeFeedbackInfo::UninitializedSentinel(masm->isolate()),
-            masm->isolate()->heap()->the_hole_value());
+            masm->isolate()->heap()->uninitialized_symbol());
 
   // Load the cache state into t0.
   __ sll(t0, a3, kPointerSizeLog2 - kSmiTagSize);
   __ Addu(t0, a2, Operand(t0));
   __ lw(t0, FieldMemOperand(t0, FixedArray::kHeaderSize));
 
   // A monomorphic cache hit or an already megamorphic state: invoke the
   // function without changing the state.
   __ Branch(&done, eq, t0, Operand(a1));
 
   // If we came here, we need to see if we are the array function.
   // If we didn't have a matching function, and we didn't find the megamorph
   // sentinel, then we have in the slot either some other function or an
   // AllocationSite. Do a map check on the object in a3.
   __ lw(t1, FieldMemOperand(t0, 0));
   __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
   __ Branch(&miss, ne, t1, Operand(at));
 
   // Make sure the function is the Array() function
   __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, t0);
   __ Branch(&megamorphic, ne, a1, Operand(t0));
   __ jmp(&done);
 
   __ bind(&miss);
 
   // A monomorphic miss (i.e, here the cache is not uninitialized) goes
   // megamorphic.
-  __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
+  __ LoadRoot(at, Heap::kUninitializedSymbolRootIndex);
   __ Branch(&initialize, eq, t0, Operand(at));
   // MegamorphicSentinel is an immortal immovable object (undefined) so no
   // write-barrier is needed.
   __ bind(&megamorphic);
   __ sll(t0, a3, kPointerSizeLog2 - kSmiTagSize);
   __ Addu(t0, a2, Operand(t0));
-  __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(at, Heap::kMegamorphicSymbolRootIndex);
   __ sw(at, FieldMemOperand(t0, FixedArray::kHeaderSize));
   __ jmp(&done);
 
   // An uninitialized cache is patched with the function or sentinel to
   // indicate the ElementsKind if function is the Array constructor.
   __ bind(&initialize);
   // Make sure the function is the Array() function
   __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, t0);
   __ Branch(&not_array_function, ne, a1, Operand(t0));
 
@@ skipping 31 matching lines @@
                  EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
   __ Pop(t0, a2, a1);
 
   __ bind(&done);
 }
 
 
 void CallFunctionStub::Generate(MacroAssembler* masm) {
   // a1 : the function to call
   // a2 : feedback vector
-  // a3 : (only if a2 is not undefined) slot in feedback vector (Smi)
+  // a3 : (only if a2 is not the megamorphic symbol) slot in feedback
+  //      vector (Smi)
   Label slow, non_function, wrap, cont;
 
   if (NeedsChecks()) {
     // Check that the function is really a JavaScript function.
     // a1: pushed function (to be verified)
     __ JumpIfSmi(a1, &non_function);
 
     // Goto slow case if we do not have a function.
     __ GetObjectType(a1, t0, t0);
     __ Branch(&slow, ne, t0, Operand(JS_FUNCTION_TYPE));
@@ skipping 12 matching lines @@
       // Do not transform the receiver for strict mode functions and natives.
       __ lw(a3, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
       __ lw(t0, FieldMemOperand(a3, SharedFunctionInfo::kCompilerHintsOffset));
       int32_t strict_mode_function_mask =
           1 <<  (SharedFunctionInfo::kStrictModeFunction + kSmiTagSize);
       int32_t native_mask = 1 << (SharedFunctionInfo::kNative + kSmiTagSize);
       __ And(at, t0, Operand(strict_mode_function_mask | native_mask));
       __ Branch(&cont, ne, at, Operand(zero_reg));
     }
 
-    // Compute the receiver in non-strict mode.
+    // Compute the receiver in sloppy mode.
     __ lw(a3, MemOperand(sp, argc_ * kPointerSize));
 
     if (NeedsChecks()) {
       __ JumpIfSmi(a3, &wrap);
       __ GetObjectType(a3, t0, t0);
       __ Branch(&wrap, lt, t0, Operand(FIRST_SPEC_OBJECT_TYPE));
     } else {
       __ jmp(&wrap);
     }
 
     __ bind(&cont);
   }
   __ InvokeFunction(a1, actual, JUMP_FUNCTION, NullCallWrapper());
 
   if (NeedsChecks()) {
     // Slow-case: Non-function called.
     __ bind(&slow);
     if (RecordCallTarget()) {
       // If there is a call target cache, mark it megamorphic in the
       // non-function case.  MegamorphicSentinel is an immortal immovable
-      // object (undefined) so no write barrier is needed.
+      // object (megamorphic symbol) so no write barrier is needed.
       ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
-                masm->isolate()->heap()->undefined_value());
+                masm->isolate()->heap()->megamorphic_symbol());
       __ sll(t1, a3, kPointerSizeLog2 - kSmiTagSize);
       __ Addu(t1, a2, Operand(t1));
-      __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
+      __ LoadRoot(at, Heap::kMegamorphicSymbolRootIndex);
       __ sw(at, FieldMemOperand(t1, FixedArray::kHeaderSize));
     }
     // Check for function proxy.
     __ Branch(&non_function, ne, t0, Operand(JS_FUNCTION_PROXY_TYPE));
     __ push(a1);  // Put proxy as additional argument.
     __ li(a0, Operand(argc_ + 1, RelocInfo::NONE32));
     __ li(a2, Operand(0, RelocInfo::NONE32));
     __ GetBuiltinFunction(a1, Builtins::CALL_FUNCTION_PROXY);
     {
       Handle<Code> adaptor =
@@ skipping 1695 matching lines @@
     __ CheckPageFlag(regs_.object(),
                      regs_.scratch0(),
                      1 << MemoryChunk::SCAN_ON_SCAVENGE,
                      ne,
                      &dont_need_remembered_set);
 
     // First notify the incremental marker if necessary, then update the
     // remembered set.
     CheckNeedsToInformIncrementalMarker(
         masm, kUpdateRememberedSetOnNoNeedToInformIncrementalMarker, mode);
-    InformIncrementalMarker(masm, mode);
+    InformIncrementalMarker(masm);
     regs_.Restore(masm);
     __ RememberedSetHelper(object_,
                            address_,
                            value_,
                            save_fp_regs_mode_,
                            MacroAssembler::kReturnAtEnd);
 
     __ bind(&dont_need_remembered_set);
   }
 
   CheckNeedsToInformIncrementalMarker(
       masm, kReturnOnNoNeedToInformIncrementalMarker, mode);
-  InformIncrementalMarker(masm, mode);
+  InformIncrementalMarker(masm);
   regs_.Restore(masm);
   __ Ret();
 }
 
 
-void RecordWriteStub::InformIncrementalMarker(MacroAssembler* masm, Mode mode) {
+void RecordWriteStub::InformIncrementalMarker(MacroAssembler* masm) {
   regs_.SaveCallerSaveRegisters(masm, save_fp_regs_mode_);
   int argument_count = 3;
   __ PrepareCallCFunction(argument_count, regs_.scratch0());
   Register address =
       a0.is(regs_.address()) ? regs_.scratch0() : regs_.address();
   ASSERT(!address.is(regs_.object()));
   ASSERT(!address.is(a0));
   __ Move(address, regs_.address());
   __ Move(a0, regs_.object());
   __ Move(a1, address);
   __ li(a2, Operand(ExternalReference::isolate_address(masm->isolate())));
 
   AllowExternalCallThatCantCauseGC scope(masm);
-  if (mode == INCREMENTAL_COMPACTION) {
-    __ CallCFunction(
-        ExternalReference::incremental_evacuation_record_write_function(
-            masm->isolate()),
-        argument_count);
-  } else {
-    ASSERT(mode == INCREMENTAL);
-    __ CallCFunction(
-        ExternalReference::incremental_marking_record_write_function(
-            masm->isolate()),
-        argument_count);
-  }
+  __ CallCFunction(
+      ExternalReference::incremental_marking_record_write_function(
+          masm->isolate()),
+      argument_count);
   regs_.RestoreCallerSaveRegisters(masm, save_fp_regs_mode_);
 }
 
 
 void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
     MacroAssembler* masm,
     OnNoNeedToInformIncrementalMarker on_no_need,
     Mode mode) {
   Label on_black;
   Label need_incremental;
@@ skipping 395 matching lines @@
   } else {
     UNREACHABLE();
   }
 }
 
 
 void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a0 : argc (only if argument_count_ == ANY)
   //  -- a1 : constructor
-  //  -- a2 : feedback vector (fixed array or undefined)
+  //  -- a2 : feedback vector (fixed array or megamorphic symbol)
   //  -- a3 : slot index (if a2 is fixed array)
   //  -- sp[0] : return address
   //  -- sp[4] : last argument
   // -----------------------------------
+
+  ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
+            masm->isolate()->heap()->megamorphic_symbol());
+
   if (FLAG_debug_code) {
     // The array construct code is only set for the global and natives
     // builtin Array functions which always have maps.
 
     // Initial map for the builtin Array function should be a map.
     __ lw(t0, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     __ SmiTst(t0, at);
     __ Assert(ne, kUnexpectedInitialMapForArrayFunction,
         at, Operand(zero_reg));
     __ GetObjectType(t0, t0, t1);
     __ Assert(eq, kUnexpectedInitialMapForArrayFunction,
         t1, Operand(MAP_TYPE));
 
-    // We should either have undefined in a2 or a valid fixed array.
+    // We should either have the megamorphic symbol in a2 or a valid
+    // fixed array.
     Label okay_here;
     Handle<Map> fixed_array_map = masm->isolate()->factory()->fixed_array_map();
-    __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(at, Heap::kMegamorphicSymbolRootIndex);
     __ Branch(&okay_here, eq, a2, Operand(at));
     __ lw(t0, FieldMemOperand(a2, 0));
     __ Assert(eq, kExpectedFixedArrayInRegisterA2,
         t0, Operand(fixed_array_map));
 
     // a3 should be a smi if we don't have undefined in a2
     __ AssertSmi(a3);
 
     __ bind(&okay_here);
   }
 
   Label no_info;
   // Get the elements kind and case on that.
-  __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(at, Heap::kMegamorphicSymbolRootIndex);
   __ Branch(&no_info, eq, a2, Operand(at));
   __ sll(t0, a3, kPointerSizeLog2 - kSmiTagSize);
   __ Addu(a2, a2, Operand(t0));
   __ lw(a2, FieldMemOperand(a2, FixedArray::kHeaderSize));
 
   // If the feedback vector is undefined, or contains anything other than an
   // AllocationSite, call an array constructor that doesn't use AllocationSites.
   __ lw(t0, FieldMemOperand(a2, 0));
   __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
   __ Branch(&no_info, ne, t0, Operand(at));
@@ skipping 224 matching lines @@
                               MemOperand(fp, 6 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS