[stubs] Port LoadScriptContextFieldStub and StoreScriptContextFieldStub to TurboFan.

BUG=v8:5269

Review-Url: https://codereview.chromium.org/2325013004
Cr-Commit-Position: refs/heads/master@{#39376}

src/code-stub-assembler.cc

@@ -1172,9 +1172,13 @@ Node* CodeStubAssembler::LoadDoubleWithHoleCheck(Node* base, Node* offset,
   return Load(machine_type, base, offset);
 }
 
+Node* CodeStubAssembler::LoadContextElement(Node* context, int slot_index) {
+  int offset = Context::SlotOffset(slot_index);
+  return Load(MachineType::AnyTagged(), context, IntPtrConstant(offset));
+}
+
 Node* CodeStubAssembler::LoadNativeContext(Node* context) {
-  return LoadFixedArrayElement(context,
-                               IntPtrConstant(Context::NATIVE_CONTEXT_INDEX));
+  return LoadContextElement(context, Context::NATIVE_CONTEXT_INDEX);
 }
 
 Node* CodeStubAssembler::LoadJSArrayElementsMap(ElementsKind kind,
@@ -4434,9 +4438,8 @@ void CodeStubAssembler::LoadGlobalIC(const LoadICParameters* p) {
     AssertInstanceType(handler, CODE_TYPE);
     LoadWithVectorDescriptor descriptor(isolate());
     Node* native_context = LoadNativeContext(p->context);
-    Node* receiver = LoadFixedArrayElement(
-        native_context, IntPtrConstant(Context::EXTENSION_INDEX), 0,
-        INTPTR_PARAMETERS);
+    Node* receiver =
+        LoadContextElement(native_context, Context::EXTENSION_INDEX);
     Node* fake_name = IntPtrConstant(0);
     TailCallStub(descriptor, handler, p->context, receiver, fake_name, p->slot,
                  p->vector);
@@ -4577,7 +4580,11 @@ Node* CodeStubAssembler::EmitKeyedSloppyArguments(Node* receiver, Node* key,
     mapped_index = SmiUntag(mapped_index);
     Node* the_context = LoadFixedArrayElement(elements, IntPtrConstant(0), 0,
                                               INTPTR_PARAMETERS);
+    // Assert that we can use LoadFixedArrayElement/StoreFixedArrayElement
+    // methods for accessing Context.
     STATIC_ASSERT(Context::kHeaderSize == FixedArray::kHeaderSize);
+    DCHECK_EQ(Context::SlotOffset(0) + kHeapObjectTag,
+              FixedArray::OffsetOfElementAt(0));
     if (is_load) {
       Node* result = LoadFixedArrayElement(the_context, mapped_index, 0,
                                            INTPTR_PARAMETERS);
@@ -4619,6 +4626,17 @@ Node* CodeStubAssembler::EmitKeyedSloppyArguments(Node* receiver, Node* key,
   return var_result.value();
 }
 
+Node* CodeStubAssembler::LoadScriptContext(Node* context, int context_index) {
+  Node* native_context = LoadNativeContext(context);
+  Node* script_context_table =
+      LoadContextElement(native_context, Context::SCRIPT_CONTEXT_TABLE_INDEX);
+
+  int offset =
+      ScriptContextTable::GetContextOffset(context_index) - kHeapObjectTag;
+  return Load(MachineType::AnyTagged(), script_context_table,
+              IntPtrConstant(offset));
+}
+
 Node* CodeStubAssembler::EnumLength(Node* map) {
   Node* bitfield_3 = LoadMapBitField3(map);
   Node* enum_length = BitFieldDecode<Map::EnumLengthBits>(bitfield_3);

src/code-stub-assembler.h

@@ -274,6 +274,7 @@ class CodeStubAssembler : public compiler::CodeAssembler {
       MachineType machine_type = MachineType::Float64());
 
   // Context manipulation
+  compiler::Node* LoadContextElement(compiler::Node* context, int slot_index);
   compiler::Node* LoadNativeContext(compiler::Node* context);
 
   compiler::Node* LoadJSArrayElementsMap(ElementsKind kind,
@@ -658,6 +659,9 @@ class CodeStubAssembler : public compiler::CodeAssembler {
     EmitKeyedSloppyArguments(receiver, key, value, bailout);
   }
 
+  // Loads script context from the script context table.
+  compiler::Node* LoadScriptContext(compiler::Node* context, int context_index);
+
   void LoadIC(const LoadICParameters* p);
   void LoadGlobalIC(const LoadICParameters* p);
   void KeyedLoadIC(const LoadICParameters* p);

src/code-stubs-hydrogen.cc

@@ -418,40 +418,6 @@ Handle<Code> FastCloneShallowArrayStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
-template <>
-HValue* CodeStubGraphBuilder<LoadScriptContextFieldStub>::BuildCodeStub() {
-  int context_index = casted_stub()->context_index();
-  int slot_index = casted_stub()->slot_index();
-
-  HValue* script_context = BuildGetScriptContext(context_index);
-  return Add<HLoadNamedField>(script_context, nullptr,
-                              HObjectAccess::ForContextSlot(slot_index));
-}
-
-
-Handle<Code> LoadScriptContextFieldStub::GenerateCode() {
-  return DoGenerateCode(this);
-}
-
-
-template <>
-HValue* CodeStubGraphBuilder<StoreScriptContextFieldStub>::BuildCodeStub() {
-  int context_index = casted_stub()->context_index();
-  int slot_index = casted_stub()->slot_index();
-
-  HValue* script_context = BuildGetScriptContext(context_index);
-  Add<HStoreNamedField>(script_context,
-                        HObjectAccess::ForContextSlot(slot_index),
-                        GetParameter(2), STORE_TO_INITIALIZED_ENTRY);
-  // TODO(ishell): Remove this unused stub.
-  return GetParameter(2);
-}
-
-
-Handle<Code> StoreScriptContextFieldStub::GenerateCode() {
-  return DoGenerateCode(this);
-}
-
 HValue* CodeStubGraphBuilderBase::BuildPushElement(HValue* object, HValue* argc,
                                                    HValue* argument_elements,
                                                    ElementsKind kind) {

src/code-stubs.cc

@@ -4615,6 +4615,39 @@ void KeyedStoreSloppyArgumentsStub::GenerateAssembly(
   }
 }
 
+void LoadScriptContextFieldStub::GenerateAssembly(
+    CodeStubAssembler* assembler) const {
+  typedef compiler::Node Node;
+
+  assembler->Comment("LoadScriptContextFieldStub: context_index=%d, slot=%d",
+                     context_index(), slot_index());
+
+  Node* context = assembler->Parameter(Descriptor::kContext);
+
+  Node* script_context = assembler->LoadScriptContext(context, context_index());
+  Node* result = assembler->LoadFixedArrayElement(
+      script_context, assembler->IntPtrConstant(slot_index()), 0,
+      CodeStubAssembler::INTPTR_PARAMETERS);
+  assembler->Return(result);
+}
+
+void StoreScriptContextFieldStub::GenerateAssembly(
+    CodeStubAssembler* assembler) const {
+  typedef compiler::Node Node;
+
+  assembler->Comment("StoreScriptContextFieldStub: context_index=%d, slot=%d",
+                     context_index(), slot_index());
+
+  Node* value = assembler->Parameter(Descriptor::kValue);
+  Node* context = assembler->Parameter(Descriptor::kContext);
+
+  Node* script_context = assembler->LoadScriptContext(context, context_index());
+  assembler->StoreFixedArrayElement(
+      script_context, assembler->IntPtrConstant(slot_index()), value,
+      UPDATE_WRITE_BARRIER, CodeStubAssembler::INTPTR_PARAMETERS);
+  assembler->Return(value);
+}
+
 // static
 compiler::Node* LessThanStub::Generate(CodeStubAssembler* assembler,
                                        compiler::Node* lhs, compiler::Node* rhs,

src/code-stubs.h

@@ -86,9 +86,7 @@ class ObjectLiteral;
   V(LoadDictionaryElement)                    \
   V(LoadFastElement)                          \
   V(LoadField)                                \
-  V(LoadScriptContextField)                   \
   V(StoreFastElement)                         \
-  V(StoreScriptContextField)                  \
   V(StoreTransition)                          \
   /* These should never be ported to TF */    \
   /* because they are either used only by */  \
@@ -150,6 +148,8 @@ class ObjectLiteral;
   V(NotEqual)                                 \
   V(KeyedLoadSloppyArguments)                 \
   V(KeyedStoreSloppyArguments)                \
+  V(LoadScriptContextField)                   \
+  V(StoreScriptContextField)                  \
   V(StrictEqual)                              \
   V(StrictNotEqual)                           \
   V(StringEqual)                              \
@@ -2682,23 +2682,21 @@ class DoubleToIStub : public PlatformCodeStub {
   DEFINE_PLATFORM_CODE_STUB(DoubleToI, PlatformCodeStub);
 };
 
-
-class ScriptContextFieldStub : public HandlerStub {
+class ScriptContextFieldStub : public TurboFanCodeStub {
  public:
   ScriptContextFieldStub(Isolate* isolate,
                          const ScriptContextTable::LookupResult* lookup_result)
-      : HandlerStub(isolate) {
+      : TurboFanCodeStub(isolate) {
     DCHECK(Accepted(lookup_result));
-    STATIC_ASSERT(kContextIndexBits + kSlotIndexBits <= kSubMinorKeyBits);
-    set_sub_minor_key(ContextIndexBits::encode(lookup_result->context_index) |
-                      SlotIndexBits::encode(lookup_result->slot_index));
+    minor_key_ = ContextIndexBits::encode(lookup_result->context_index) |
+                 SlotIndexBits::encode(lookup_result->slot_index);
   }
 
-  int context_index() const {
-    return ContextIndexBits::decode(sub_minor_key());
-  }
+  Code::Kind GetCodeKind() const override { return Code::HANDLER; }
 
-  int slot_index() const { return SlotIndexBits::decode(sub_minor_key()); }
+  int context_index() const { return ContextIndexBits::decode(minor_key_); }
+
+  int slot_index() const { return SlotIndexBits::decode(minor_key_); }
 
   static bool Accepted(const ScriptContextTable::LookupResult* lookup_result) {
     return ContextIndexBits::is_valid(lookup_result->context_index) &&
@@ -2712,7 +2710,7 @@ class ScriptContextFieldStub : public HandlerStub {
   class SlotIndexBits
       : public BitField<int, kContextIndexBits, kSlotIndexBits> {};
 
-  DEFINE_CODE_STUB_BASE(ScriptContextFieldStub, HandlerStub);
+  DEFINE_CODE_STUB_BASE(ScriptContextFieldStub, TurboFanCodeStub);
 };
 
 
@@ -2722,11 +2720,11 @@ class LoadScriptContextFieldStub : public ScriptContextFieldStub {
       Isolate* isolate, const ScriptContextTable::LookupResult* lookup_result)
       : ScriptContextFieldStub(isolate, lookup_result) {}
 
- private:
-  Code::Kind kind() const override { return Code::LOAD_IC; }
+  ExtraICState GetExtraICState() const override { return Code::LOAD_IC; }
 
+ private:
   DEFINE_CALL_INTERFACE_DESCRIPTOR(LoadWithVector);
-  DEFINE_HANDLER_CODE_STUB(LoadScriptContextField, ScriptContextFieldStub);
+  DEFINE_TURBOFAN_CODE_STUB(LoadScriptContextField, ScriptContextFieldStub);
 };
 
 
@@ -2736,11 +2734,11 @@ class StoreScriptContextFieldStub : public ScriptContextFieldStub {
       Isolate* isolate, const ScriptContextTable::LookupResult* lookup_result)
       : ScriptContextFieldStub(isolate, lookup_result) {}
 
- private:
-  Code::Kind kind() const override { return Code::STORE_IC; }
+  ExtraICState GetExtraICState() const override { return Code::STORE_IC; }
 
+ private:
   DEFINE_CALL_INTERFACE_DESCRIPTOR(StoreWithVector);
-  DEFINE_HANDLER_CODE_STUB(StoreScriptContextField, ScriptContextFieldStub);
+  DEFINE_TURBOFAN_CODE_STUB(StoreScriptContextField, ScriptContextFieldStub);
 };
 
 

src/crankshaft/hydrogen.cc

@@ -3402,16 +3402,6 @@ HInstruction* HGraphBuilder::BuildGetNativeContext(HValue* closure) {
 }
 
 
-HInstruction* HGraphBuilder::BuildGetScriptContext(int context_index) {
-  HValue* native_context = BuildGetNativeContext();
-  HValue* script_context_table = Add<HLoadNamedField>(
-      native_context, nullptr,
-      HObjectAccess::ForContextSlot(Context::SCRIPT_CONTEXT_TABLE_INDEX));
-  return Add<HLoadNamedField>(script_context_table, nullptr,
-                              HObjectAccess::ForScriptContext(context_index));
-}
-
-
 HValue* HGraphBuilder::BuildGetParentContext(HValue* depth, int depth_value) {
   HValue* script_context = context();
   if (depth != NULL) {

src/crankshaft/hydrogen.h

@@ -1860,7 +1860,7 @@ class HGraphBuilder {
 
   HInstruction* BuildGetNativeContext(HValue* closure);
   HInstruction* BuildGetNativeContext();
-  HInstruction* BuildGetScriptContext(int context_index);
+
   // Builds a loop version if |depth| is specified or unrolls the loop to
   // |depth_value| iterations otherwise.
   HValue* BuildGetParentContext(HValue* depth, int depth_value);