[stubs] Factor CSA::GrowElementsCapacity() out of existing code.

... and rename CheckAndGrowElementsCapacity() to TryGrowElementsCapacity().

Review-Url: https://codereview.chromium.org/2324863002
Cr-Commit-Position: refs/heads/master@{#39307}

src/builtins/builtins-internal.cc

@@ -108,9 +108,8 @@ void Builtins::Generate_GrowFastDoubleElements(CodeStubAssembler* assembler) {
 
   Label runtime(assembler, CodeStubAssembler::Label::kDeferred);
   Node* elements = assembler->LoadElements(object);
-  elements = assembler->CheckAndGrowElementsCapacity(
-      context, elements, FAST_DOUBLE_ELEMENTS, key, &runtime);
-  assembler->StoreObjectField(object, JSObject::kElementsOffset, elements);
+  elements = assembler->TryGrowElementsCapacity(
+      object, elements, FAST_DOUBLE_ELEMENTS, key, &runtime);
   assembler->Return(elements);
 
   assembler->Bind(&runtime);
@@ -129,9 +128,8 @@ void Builtins::Generate_GrowFastSmiOrObjectElements(
 
   Label runtime(assembler, CodeStubAssembler::Label::kDeferred);
   Node* elements = assembler->LoadElements(object);
-  elements = assembler->CheckAndGrowElementsCapacity(
-      context, elements, FAST_ELEMENTS, key, &runtime);
-  assembler->StoreObjectField(object, JSObject::kElementsOffset, elements);
+  elements = assembler->TryGrowElementsCapacity(object, elements, FAST_ELEMENTS,
+                                                key, &runtime);
   assembler->Return(elements);
 
   assembler->Bind(&runtime);

src/code-stub-assembler.cc

@@ -1690,43 +1690,64 @@ Node* CodeStubAssembler::CalculateNewElementsCapacity(Node* old_capacity,
   }
 }
 
-Node* CodeStubAssembler::CheckAndGrowElementsCapacity(Node* context,
-                                                      Node* elements,
-                                                      ElementsKind kind,
-                                                      Node* key, Label* fail) {
+Node* CodeStubAssembler::TryGrowElementsCapacity(Node* object, Node* elements,
+                                                 ElementsKind kind, Node* key,
+                                                 Label* bailout) {
   Node* capacity = LoadFixedArrayBaseLength(elements);
 
   ParameterMode mode = OptimalParameterMode();
   capacity = UntagParameter(capacity, mode);
   key = UntagParameter(key, mode);
 
+  return TryGrowElementsCapacity(object, elements, kind, key, capacity, mode,
+                                 bailout);
+}
+
+Node* CodeStubAssembler::TryGrowElementsCapacity(Node* object, Node* elements,
+                                                 ElementsKind kind, Node* key,
+                                                 Node* capacity,
+                                                 ParameterMode mode,
+                                                 Label* bailout) {
+  Comment("TryGrowElementsCapacity");
+
   // If the gap growth is too big, fall back to the runtime.
   Node* max_gap = IntPtrOrSmiConstant(JSObject::kMaxGap, mode);
   Node* max_capacity = IntPtrAdd(capacity, max_gap);
-  GotoIf(UintPtrGreaterThanOrEqual(key, max_capacity), fail);
+  GotoIf(UintPtrGreaterThanOrEqual(key, max_capacity), bailout);
 
-  // Calculate the capacity of the new backing tore
+  // Calculate the capacity of the new backing store.
   Node* new_capacity = CalculateNewElementsCapacity(
       IntPtrAdd(key, IntPtrOrSmiConstant(1, mode)), mode);
+  return GrowElementsCapacity(object, elements, kind, kind, capacity,
+                              new_capacity, mode, bailout);
+}
 
+Node* CodeStubAssembler::GrowElementsCapacity(
+    Node* object, Node* elements, ElementsKind from_kind, ElementsKind to_kind,
+    Node* capacity, Node* new_capacity, ParameterMode mode, Label* bailout) {
+  Comment("[ GrowElementsCapacity");
   // 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(kind);
+  // 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)),
-         fail);
+         bailout);
 
   // Allocate the new backing store.
-  Node* new_elements = AllocateFixedArray(kind, new_capacity, mode);
+  Node* new_elements = AllocateFixedArray(to_kind, new_capacity, mode);
 
   // Fill in the added capacity in the new store with holes.
-  FillFixedArrayWithValue(kind, new_elements, capacity, new_capacity,
+  FillFixedArrayWithValue(to_kind, new_elements, capacity, new_capacity,
                           Heap::kTheHoleValueRootIndex, mode);
 
   // Copy the elements from the old elements store to the new.
-  CopyFixedArrayElements(kind, elements, new_elements, capacity,
-                         SKIP_WRITE_BARRIER, mode);
+  // 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;
 }
 

src/code-stub-assembler.h

@@ -366,11 +366,28 @@ class CodeStubAssembler : public compiler::CodeAssembler {
   compiler::Node* CalculateNewElementsCapacity(
       compiler::Node* old_capacity, ParameterMode mode = INTEGER_PARAMETERS);
 
-  compiler::Node* CheckAndGrowElementsCapacity(compiler::Node* context,
-                                               compiler::Node* elements,
-                                               ElementsKind kind,
-                                               compiler::Node* key,
-                                               Label* fail);
+  // Tries to grow the |elements| array of given |object| to store the |key|
+  // or bails out if the growing gap is too big. Returns new elements.
+  compiler::Node* TryGrowElementsCapacity(compiler::Node* object,
+                                          compiler::Node* elements,
+                                          ElementsKind kind,
+                                          compiler::Node* key, Label* bailout);
+
+  // Tries to grow the |capacity|-length |elements| array of given |object|
+  // to store the |key| or bails out if the growing gap is too big. Returns
+  // new elements.
+  compiler::Node* TryGrowElementsCapacity(compiler::Node* object,
+                                          compiler::Node* elements,
+                                          ElementsKind kind,
+                                          compiler::Node* key,
+                                          compiler::Node* capacity,
+                                          ParameterMode mode, Label* bailout);
+
+  // Grows elements capacity of given object. Returns new elements.
+  compiler::Node* GrowElementsCapacity(
+      compiler::Node* object, compiler::Node* elements, ElementsKind from_kind,
+      ElementsKind to_kind, compiler::Node* capacity,
+      compiler::Node* new_capacity, ParameterMode mode, Label* bailout);
 
   // Allocation site manipulation
   void InitializeAllocationMemento(compiler::Node* base_allocation,

src/code-stubs.cc

@@ -5798,9 +5798,8 @@ void GrowArrayElementsStub::GenerateAssembly(
   ElementsKind kind = elements_kind();
 
   Node* elements = assembler->LoadElements(object);
-  Node* new_elements = assembler->CheckAndGrowElementsCapacity(
-      context, elements, kind, key, &runtime);
-  assembler->StoreObjectField(object, JSObject::kElementsOffset, new_elements);
+  Node* new_elements =
+      assembler->TryGrowElementsCapacity(object, elements, kind, key, &runtime);
   assembler->Return(new_elements);
 
   assembler->Bind(&runtime);