[stubs] Port KeyedStoreIC_Megamorphic stub to Turbofan

src/code-stub-assembler.cc

 // Copyright 2016 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.
 #include "src/code-stub-assembler.h"
 #include "src/code-factory.h"
 #include "src/frames-inl.h"
 #include "src/frames.h"
 #include "src/ic/handler-configuration.h"
 #include "src/ic/stub-cache.h"
 
@@ skipping 2227 matching lines @@
   // If size of the allocation for the new capacity doesn't fit in a page
   // that we can bump-pointer allocate from, fall back to the runtime.
   int max_size = FixedArrayBase::GetMaxLengthForNewSpaceAllocation(to_kind);
   GotoIf(UintPtrGreaterThanOrEqual(new_capacity,
                                    IntPtrOrSmiConstant(max_size, mode)),
          bailout);
 
   // Allocate the new backing store.
   Node* new_elements = AllocateFixedArray(to_kind, new_capacity, mode);
 
-  // Fill in the added capacity in the new store with holes.
-  FillFixedArrayWithValue(to_kind, new_elements, capacity, new_capacity,
-                          Heap::kTheHoleValueRootIndex, mode);
-
   // Copy the elements from the old elements store to the new.
   // The size-check above guarantees that the |new_elements| is allocated
   // in new space so we can skip the write barrier.
   CopyFixedArrayElements(from_kind, elements, to_kind, new_elements, capacity,
                          new_capacity, SKIP_WRITE_BARRIER, mode);
 
   StoreObjectField(object, JSObject::kElementsOffset, new_elements);
   Comment("] GrowElementsCapacity");
   return new_elements;
 }
@@ skipping 3009 matching lines @@
   Bind(&done);
   return var_intptr_key.value();
 }
 
 void CodeStubAssembler::EmitFastElementsBoundsCheck(Node* object,
                                                     Node* elements,
                                                     Node* intptr_index,
                                                     Node* is_jsarray_condition,
                                                     Label* miss) {
   Variable var_length(this, MachineType::PointerRepresentation());
+  Comment("Fast elements bounds check");
   Label if_array(this), length_loaded(this, &var_length);
   GotoIf(is_jsarray_condition, &if_array);
   {
     var_length.Bind(SmiUntag(LoadFixedArrayBaseLength(elements)));
     Goto(&length_loaded);
   }
   Bind(&if_array);
   {
     var_length.Bind(SmiUntag(LoadJSArrayLength(object)));
     Goto(&length_loaded);
   }
   Bind(&length_loaded);
   GotoUnless(UintPtrLessThan(intptr_index, var_length.value()), miss);
 }
 
 void CodeStubAssembler::EmitElementLoad(Node* object, Node* elements,
                                         Node* elements_kind, Node* intptr_index,
                                         Node* is_jsarray_condition,
                                         Label* if_hole, Label* rebox_double,
                                         Variable* var_double_value,
                                         Label* unimplemented_elements_kind,
                                         Label* out_of_bounds, Label* miss) {
   Label if_typed_array(this), if_fast_packed(this), if_fast_holey(this),
       if_fast_double(this), if_fast_holey_double(this), if_nonfast(this),
-      if_dictionary(this), unreachable(this);
+      if_dictionary(this);
   GotoIf(
       IntPtrGreaterThan(elements_kind, IntPtrConstant(LAST_FAST_ELEMENTS_KIND)),
       &if_nonfast);
 
   EmitFastElementsBoundsCheck(object, elements, intptr_index,
                               is_jsarray_condition, out_of_bounds);
   int32_t kinds[] = {// Handled by if_fast_packed.
                      FAST_SMI_ELEMENTS, FAST_ELEMENTS,
                      // Handled by if_fast_holey.
                      FAST_HOLEY_SMI_ELEMENTS, FAST_HOLEY_ELEMENTS,
@@ skipping 3597 matching lines @@
 }
 
 void CodeStubArguments::PopAndReturn(compiler::Node* value) {
   assembler_->PopAndReturn(
       assembler_->IntPtrAddFoldConstants(argc_, assembler_->IntPtrConstant(1)),
       value);
 }
 
 }  // namespace internal
 }  // namespace v8