[stubs] Turn FastCloneRegExpStub into a TurboFan code stub.

R=danno@chromium.org
BUG=chromium:608675

Review-Url: https://codereview.chromium.org/2207553002
Cr-Commit-Position: refs/heads/master@{#38302}

src/code-stubs-hydrogen.cc

@@ -343,63 +343,6 @@ Handle<Code> NumberToStringStub::GenerateCode() {
 }
 
 
-template <>
-HValue* CodeStubGraphBuilder<FastCloneRegExpStub>::BuildCodeStub() {
-  HValue* closure = GetParameter(Descriptor::kClosure);
-  HValue* literal_index = GetParameter(Descriptor::kLiteralIndex);
-
-  // This stub is very performance sensitive, the generated code must be tuned
-  // so that it doesn't build and eager frame.
-  info()->MarkMustNotHaveEagerFrame();
-
-  HValue* literals_array = Add<HLoadNamedField>(
-      closure, nullptr, HObjectAccess::ForLiteralsPointer());
-  HInstruction* boilerplate = Add<HLoadKeyed>(
-      literals_array, literal_index, nullptr, nullptr, FAST_ELEMENTS,
-      NEVER_RETURN_HOLE, LiteralsArray::kOffsetToFirstLiteral - kHeapObjectTag);
-
-  IfBuilder if_notundefined(this);
-  if_notundefined.IfNot<HCompareObjectEqAndBranch>(
-      boilerplate, graph()->GetConstantUndefined());
-  if_notundefined.Then();
-  {
-    int result_size =
-        JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
-    HValue* result =
-        Add<HAllocate>(Add<HConstant>(result_size), HType::JSObject(),
-                       NOT_TENURED, JS_REGEXP_TYPE, graph()->GetConstant0());
-    Add<HStoreNamedField>(
-        result, HObjectAccess::ForMap(),
-        Add<HLoadNamedField>(boilerplate, nullptr, HObjectAccess::ForMap()));
-    Add<HStoreNamedField>(
-        result, HObjectAccess::ForPropertiesPointer(),
-        Add<HLoadNamedField>(boilerplate, nullptr,
-                             HObjectAccess::ForPropertiesPointer()));
-    Add<HStoreNamedField>(
-        result, HObjectAccess::ForElementsPointer(),
-        Add<HLoadNamedField>(boilerplate, nullptr,
-                             HObjectAccess::ForElementsPointer()));
-    for (int offset = JSObject::kHeaderSize; offset < result_size;
-         offset += kPointerSize) {
-      HObjectAccess access = HObjectAccess::ForObservableJSObjectOffset(offset);
-      Add<HStoreNamedField>(result, access,
-                            Add<HLoadNamedField>(boilerplate, nullptr, access));
-    }
-    Push(result);
-  }
-  if_notundefined.ElseDeopt(
-      DeoptimizeReason::kUninitializedBoilerplateInFastClone);
-  if_notundefined.End();
-
-  return Pop();
-}
-
-
-Handle<Code> FastCloneRegExpStub::GenerateCode() {
-  return DoGenerateCode(this);
-}
-
-
 template <>
 HValue* CodeStubGraphBuilder<FastCloneShallowArrayStub>::BuildCodeStub() {
   Factory* factory = isolate()->factory();

src/code-stubs.cc

@@ -4157,14 +4157,6 @@ void NumberToStringStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
 }
 
 
-void FastCloneRegExpStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
-  FastCloneRegExpDescriptor call_descriptor(isolate());
-  descriptor->Initialize(
-      Runtime::FunctionForId(Runtime::kCreateRegExpLiteral)->entry);
-  descriptor->SetMissHandler(Runtime::kCreateRegExpLiteral);
-}
-
-
 void FastCloneShallowArrayStub::InitializeDescriptor(
     CodeStubDescriptor* descriptor) {
   FastCloneShallowArrayDescriptor call_descriptor(isolate());
@@ -4631,6 +4623,45 @@ void FastNewFunctionContextStub::GenerateAssembly(
   assembler->Return(Generate(assembler, function, slots, context));
 }
 
+void FastCloneRegExpStub::GenerateAssembly(CodeStubAssembler* assembler) const {
+  typedef CodeStubAssembler::Label Label;
+  typedef compiler::Node Node;
+
+  Label call_runtime(assembler, Label::kDeferred);
+
+  Node* closure = assembler->Parameter(Descriptor::kClosure);
+  Node* literal_index = assembler->Parameter(Descriptor::kLiteralIndex);
+
+  Node* undefined = assembler->UndefinedConstant();
+  Node* literals_array =
+      assembler->LoadObjectField(closure, JSFunction::kLiteralsOffset);
+  Node* boilerplate = assembler->LoadFixedArrayElement(
+      literals_array, literal_index,
+      LiteralsArray::kFirstLiteralIndex * kPointerSize,
+      CodeStubAssembler::SMI_PARAMETERS);
+  assembler->GotoIf(assembler->WordEqual(boilerplate, undefined),
+                    &call_runtime);
+
+  {
+    int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
+    Node* copy = assembler->Allocate(size);
+    for (int offset = 0; offset < size; offset += kPointerSize) {
+      Node* value = assembler->LoadObjectField(boilerplate, offset);
+      assembler->StoreObjectFieldNoWriteBarrier(copy, offset, value);
+    }
+    assembler->Return(copy);
+  }
+
+  assembler->Bind(&call_runtime);
+  {
+    Node* context = assembler->Parameter(Descriptor::kContext);
+    Node* pattern = assembler->Parameter(Descriptor::kPattern);
+    Node* flags = assembler->Parameter(Descriptor::kFlags);
+    assembler->TailCallRuntime(Runtime::kCreateRegExpLiteral, context, closure,
+                               literal_index, pattern, flags);
+  }
+}
+
 void CreateAllocationSiteStub::GenerateAheadOfTime(Isolate* isolate) {
   CreateAllocationSiteStub stub(isolate);
   stub.GetCode();

src/code-stubs.h

@@ -67,7 +67,6 @@ namespace internal {
   V(StoreICTrampoline)                        \
   /* --- HydrogenCodeStubs --- */             \
   V(ElementsTransitionAndStore)               \
-  V(FastCloneRegExp)                          \
   V(FastCloneShallowArray)                    \
   V(GrowArrayElements)                        \
   V(NumberToString)                           \
@@ -138,6 +137,7 @@ namespace internal {
   V(InternalArraySingleArgumentConstructor)   \
   V(Dec)                                      \
   V(FastCloneShallowObject)                   \
+  V(FastCloneRegExp)                          \
   V(FastNewClosure)                           \
   V(FastNewFunctionContext)                   \
   V(InstanceOf)                               \
@@ -1165,14 +1165,13 @@ class FastNewStrictArgumentsStub final : public PlatformCodeStub {
   class SkipStubFrameBits : public BitField<bool, 0, 1> {};
 };
 
-
-class FastCloneRegExpStub final : public HydrogenCodeStub {
+class FastCloneRegExpStub final : public TurboFanCodeStub {
  public:
-  explicit FastCloneRegExpStub(Isolate* isolate) : HydrogenCodeStub(isolate) {}
+  explicit FastCloneRegExpStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
 
  private:
   DEFINE_CALL_INTERFACE_DESCRIPTOR(FastCloneRegExp);
-  DEFINE_HYDROGEN_CODE_STUB(FastCloneRegExp, HydrogenCodeStub);
+  DEFINE_TURBOFAN_CODE_STUB(FastCloneRegExp, TurboFanCodeStub);
 };
 
 

src/deoptimize-reason.h

@@ -68,8 +68,6 @@ namespace internal {
     "Unexpected cell contents in global store")                               \
   V(UnexpectedObject, "unexpected object")                                    \
   V(UnexpectedRHSOfBinaryOperation, "Unexpected RHS of binary operation")     \
-  V(UninitializedBoilerplateInFastClone,                                      \
-    "Uninitialized boilerplate in fast clone")                                \
   V(UninitializedBoilerplateLiterals, "Uninitialized boilerplate literals")   \
   V(UnknownMapInPolymorphicAccess, "Unknown map in polymorphic access")       \
   V(UnknownMapInPolymorphicCall, "Unknown map in polymorphic call")           \

src/full-codegen/full-codegen.cc

@@ -1495,6 +1495,11 @@ void FullCodeGenerator::VisitRegExpLiteral(RegExpLiteral* expr) {
   __ Move(descriptor.GetRegisterParameter(2), expr->pattern());
   __ Move(descriptor.GetRegisterParameter(3), Smi::FromInt(expr->flags()));
   __ Call(callable.code(), RelocInfo::CODE_TARGET);
+
+  // Reload the context register after the call as i.e. TurboFan code stubs
+  // won't preserve the context register.
+  LoadFromFrameField(StandardFrameConstants::kContextOffset,
+                     context_register());
   context()->Plug(result_register());
 }