Port FastCloneShallowArrayStub to Turbofan

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index 016d40770208e395f8cd60aa7c845580333ff78a..27bcbae26c3162f1fd7c1b85b0ef6e961d957616 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -5146,15 +5146,6 @@ void NumberToStringStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
   descriptor->SetMissHandler(Runtime::kNumberToString);
 }
 
-
-void FastCloneShallowArrayStub::InitializeDescriptor(
-    CodeStubDescriptor* descriptor) {
-  FastCloneShallowArrayDescriptor call_descriptor(isolate());
-  descriptor->Initialize(
-      Runtime::FunctionForId(Runtime::kCreateArrayLiteralStubBailout)->entry);
-  descriptor->SetMissHandler(Runtime::kCreateArrayLiteralStubBailout);
-}
-
 void RegExpConstructResultStub::InitializeDescriptor(
     CodeStubDescriptor* descriptor) {
   descriptor->Initialize(
@@ -5663,6 +5654,196 @@ void FastCloneRegExpStub::GenerateAssembly(CodeStubAssembler* assembler) const {
       Generate(assembler, closure, literal_index, pattern, flags, context));
 }
 
+namespace {
+
+compiler::Node* NonEmptyShallowClone(CodeStubAssembler* assembler,
+                                     compiler::Node* boilerplate,
+                                     compiler::Node* boilerplate_map,
+                                     compiler::Node* boilerplate_elements,
+                                     compiler::Node* allocation_site,
+                                     compiler::Node* capacity,
+                                     ElementsKind kind) {
+  typedef compiler::Node Node;
+  typedef CodeStubAssembler::ParameterMode ParameterMode;
+
+  ParameterMode param_mode = CodeStubAssembler::SMI_PARAMETERS;
+
+  Node* length = assembler->LoadJSArrayLength(boilerplate);
+
+  if (assembler->Is64()) {
+    capacity = assembler->SmiUntag(capacity);
+    param_mode = CodeStubAssembler::INTEGER_PARAMETERS;
+  }
+
+  Node *array, *elements;
+  std::tie(array, elements) = assembler->AllocateUninitializedJSArray(
+      kind, boilerplate_map, length, allocation_site, capacity, param_mode);
+
+  assembler->Comment("copy elements header");
+  for (int offset = 0; offset < FixedArrayBase::kHeaderSize;
+       offset += kPointerSize) {
+    Node* value = assembler->LoadObjectField(boilerplate_elements, offset);
+    assembler->StoreObjectField(elements, offset, value);
+  }
+
+  if (assembler->Is64()) {
+    length = assembler->SmiUntag(length);
+  }
+
+  assembler->Comment("copy boilerplate elements");
+  assembler->CopyFixedArrayElements(kind, boilerplate_elements, elements,
+                                    length, SKIP_WRITE_BARRIER, param_mode);
+  assembler->IncrementCounter(
+      assembler->isolate()->counters()->inlined_copied_elements(), 1);
+
+  return array;
+}
+
+}  // namespace
+
+// static
+compiler::Node* FastCloneShallowArrayStub::Generate(
+    CodeStubAssembler* assembler, compiler::Node* closure,
+    compiler::Node* literal_index, compiler::Node* constant_elements,
+    compiler::Node* context, AllocationSiteMode allocation_site_mode) {
+  typedef CodeStubAssembler::Label Label;
+  typedef CodeStubAssembler::Variable Variable;
+  typedef compiler::Node Node;
+
+  Label call_runtime(assembler, Label::kDeferred), zero_capacity(assembler),
+      cow_elements(assembler), fast_elements(assembler),
+      return_result(assembler);
+  Variable result(assembler, MachineRepresentation::kTagged);
+
+  Node* undefined = assembler->UndefinedConstant();
+
+  Node* literals_array =
+      assembler->LoadObjectField(closure, JSFunction::kLiteralsOffset);
+  Node* allocation_site = assembler->LoadFixedArrayElement(
+      literals_array, literal_index,
+      LiteralsArray::kFirstLiteralIndex * kPointerSize,
+      CodeStubAssembler::SMI_PARAMETERS);
+
+  assembler->GotoIf(assembler->WordEqual(allocation_site, undefined),
+                    &call_runtime);
+
+  Node* boilerplate = assembler->LoadObjectField(
+      allocation_site, AllocationSite::kTransitionInfoOffset);
+  Node* boilerplate_map = assembler->LoadMap(boilerplate);
+  Node* boilerplate_elements = assembler->LoadElements(boilerplate);
+  Node* capacity = assembler->LoadFixedArrayBaseLength(boilerplate_elements);
+  allocation_site =
+      allocation_site_mode == TRACK_ALLOCATION_SITE ? allocation_site : nullptr;
+
+  Node* zero = assembler->SmiConstant(Smi::FromInt(0));
+  assembler->GotoIf(assembler->SmiEqual(capacity, zero), &zero_capacity);
+
+  Node* elements_map = assembler->LoadMap(boilerplate_elements);
+  assembler->GotoIf(
+      assembler->WordEqual(elements_map, assembler->FixedCowArrayMapConstant()),
+      &cow_elements);
+
+  assembler->GotoIf(
+      assembler->WordEqual(elements_map, assembler->FixedArrayMapConstant()),
+      &fast_elements);
+  {
+    assembler->Comment("fast double elements path");
+    if (FLAG_debug_code) {
+      Label correct_elements_map(assembler), abort(assembler);

[rmcilroy, 2016/09/16 08:53:52]

kDeferred on abort label.

[klaasb, 2016/09/19 12:17:59]

Done.

+      assembler->BranchIf(
+          assembler->WordEqual(elements_map,
+                               assembler->FixedDoubleArrayMapConstant()),
+          &correct_elements_map, &abort);
+
+      assembler->Bind(&abort);
+      {
+        Node* abort_id =
+            assembler->SmiConstant(Smi::FromInt(BailoutReason::kUnexpectedMap));

[rmcilroy, 2016/09/16 08:53:52]

This could be more specific (i.e., "expected fixed double array map")

[klaasb, 2016/09/19 12:17:59]

Done.

+        assembler->TailCallRuntime(Runtime::kAbort, context, abort_id);
+      }
+      assembler->Bind(&correct_elements_map);
+    }
+    Node* array = NonEmptyShallowClone(assembler, boilerplate, boilerplate_map,

[rmcilroy, 2016/09/16 08:53:51]

nit - newline above

[klaasb, 2016/09/19 12:17:59]

Done.

+                                       boilerplate_elements, allocation_site,
+                                       capacity, FAST_DOUBLE_ELEMENTS);
+    result.Bind(array);
+    assembler->Goto(&return_result);
+  }
+
+  assembler->Bind(&fast_elements);
+  {
+    assembler->Comment("fast elements path");
+    Node* array = NonEmptyShallowClone(assembler, boilerplate, boilerplate_map,
+                                       boilerplate_elements, allocation_site,
+                                       capacity, FAST_ELEMENTS);
+    result.Bind(array);
+    assembler->Goto(&return_result);
+  }
+
+  Variable length(assembler, MachineRepresentation::kTagged),
+      elements(assembler, MachineRepresentation::kTagged);
+  Label allocate_without_elements(assembler);
+
+  assembler->Bind(&cow_elements);
+  {
+    assembler->Comment("fixed cow path");
+    length.Bind(assembler->LoadJSArrayLength(boilerplate));
+    elements.Bind(boilerplate_elements);
+
+    assembler->Goto(&allocate_without_elements);
+  }
+
+  assembler->Bind(&zero_capacity);
+  {
+    assembler->Comment("zero capacity path");
+    length.Bind(zero);
+    elements.Bind(assembler->LoadRoot(Heap::kEmptyFixedArrayRootIndex));
+
+    assembler->Goto(&allocate_without_elements);
+  }
+
+  assembler->Bind(&allocate_without_elements);
+  {
+    Node* array = assembler->AllocateUninitializedJSArrayWithoutElements(
+        FAST_ELEMENTS, boilerplate_map, length.value(), allocation_site);
+    assembler->StoreObjectField(array, JSObject::kElementsOffset,
+                                elements.value());
+    result.Bind(array);
+    assembler->Goto(&return_result);
+  }
+
+  assembler->Bind(&call_runtime);
+  {
+    assembler->Comment("call runtime");
+    Node* flags = assembler->SmiConstant(
+        Smi::FromInt(ArrayLiteral::kShallowElements |
+                     (allocation_site_mode == TRACK_ALLOCATION_SITE
+                          ? 0
+                          : ArrayLiteral::kDisableMementos)));
+    Node* array =
+        assembler->CallRuntime(Runtime::kCreateArrayLiteral, context, closure,
+                               literal_index, constant_elements, flags);
+    result.Bind(array);
+    assembler->Goto(&return_result);
+  }
+
+  assembler->Bind(&return_result);
+  return result.value();
+}
+
+void FastCloneShallowArrayStub::GenerateAssembly(
+    CodeStubAssembler* assembler) const {
+  typedef compiler::Node Node;
+  Node* closure = assembler->Parameter(Descriptor::kClosure);
+  Node* literal_index = assembler->Parameter(Descriptor::kLiteralIndex);
+  Node* constant_elements = assembler->Parameter(Descriptor::kConstantElements);
+  Node* context = assembler->Parameter(Descriptor::kContext);
+
+  assembler->Return(Generate(assembler, closure, literal_index,
+                             constant_elements, context,
+                             allocation_site_mode()));
+}
+
 void CreateAllocationSiteStub::GenerateAheadOfTime(Isolate* isolate) {
   CreateAllocationSiteStub stub(isolate);
   stub.GetCode();