[FeedbackVector] Remove FeedbackVectorSpecBase

The case that required it is no longer in the tree.

Change-Id: Ie4c82f2799c381a5a5f2f57e7e3255ebb69f02b6
Reviewed-on: https://chromium-review.googlesource.com/893262Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51018}

src/factory.cc

@@ -2552,9 +2552,7 @@ Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(
   share->set_script(*undefined_value(), SKIP_WRITE_BARRIER);
   share->set_debug_info(Smi::kZero, SKIP_WRITE_BARRIER);
   share->set_function_identifier(*undefined_value(), SKIP_WRITE_BARRIER);
-  StaticFeedbackVectorSpec empty_spec;
-  Handle<FeedbackMetadata> feedback_metadata =
-      FeedbackMetadata::New(isolate(), &empty_spec);
+  Handle<FeedbackMetadata> feedback_metadata = FeedbackMetadata::New(isolate());
   share->set_feedback_metadata(*feedback_metadata, SKIP_WRITE_BARRIER);
   share->set_function_literal_id(FunctionLiteral::kIdTypeInvalid);
 #if V8_SFI_HAS_UNIQUE_ID

src/feedback-vector.cc

@@ -12,35 +12,23 @@
 namespace v8 {
 namespace internal {
 
-template <typename Derived>
-FeedbackSlot FeedbackVectorSpecBase<Derived>::AddSlot(FeedbackSlotKind kind) {
-  int slot = This()->slots();
+FeedbackSlot FeedbackVectorSpec::AddSlot(FeedbackSlotKind kind) {
+  int slot = slots();
   int entries_per_slot = FeedbackMetadata::GetSlotSize(kind);
-  This()->append(kind);
+  append(kind);
   for (int i = 1; i < entries_per_slot; i++) {
-    This()->append(FeedbackSlotKind::kInvalid);
+    append(FeedbackSlotKind::kInvalid);
   }
   return FeedbackSlot(slot);
 }
 
-template FeedbackSlot FeedbackVectorSpecBase<FeedbackVectorSpec>::AddSlot(
-    FeedbackSlotKind kind);
-template FeedbackSlot FeedbackVectorSpecBase<StaticFeedbackVectorSpec>::AddSlot(
-    FeedbackSlotKind kind);
-
-template <typename Derived>
-FeedbackSlot FeedbackVectorSpecBase<Derived>::AddTypeProfileSlot() {
+FeedbackSlot FeedbackVectorSpec::AddTypeProfileSlot() {
   FeedbackSlot slot = AddSlot(FeedbackSlotKind::kTypeProfile);
   CHECK_EQ(FeedbackVectorSpec::kTypeProfileSlotIndex,
            FeedbackVector::GetIndex(slot));
   return slot;
 }
 
-template FeedbackSlot
-FeedbackVectorSpecBase<FeedbackVectorSpec>::AddTypeProfileSlot();
-template FeedbackSlot
-FeedbackVectorSpecBase<StaticFeedbackVectorSpec>::AddTypeProfileSlot();
-
 bool FeedbackVectorSpec::HasTypeProfileSlot() const {
   FeedbackSlot slot =
       FeedbackVector::ToSlot(FeedbackVectorSpec::kTypeProfileSlotIndex);
@@ -77,18 +65,12 @@ void FeedbackMetadata::SetKind(FeedbackSlot slot, FeedbackSlotKind kind) {
   set(index, Smi::FromInt(new_data));
 }
 
-template Handle<FeedbackMetadata> FeedbackMetadata::New(
-    Isolate* isolate, const StaticFeedbackVectorSpec* spec);
-template Handle<FeedbackMetadata> FeedbackMetadata::New(
-    Isolate* isolate, const FeedbackVectorSpec* spec);
-
 // static
-template <typename Spec>
 Handle<FeedbackMetadata> FeedbackMetadata::New(Isolate* isolate,
-                                               const Spec* spec) {
+                                               const FeedbackVectorSpec* spec) {
   Factory* factory = isolate->factory();
 
-  const int slot_count = spec->slots();
+  const int slot_count = spec == nullptr ? 0 : spec->slots();
   const int slot_kinds_length = VectorICComputer::word_count(slot_count);
   const int length = slot_kinds_length + kReservedIndexCount;
   if (length == kReservedIndexCount) {
@@ -96,6 +78,7 @@ Handle<FeedbackMetadata> FeedbackMetadata::New(Isolate* isolate,
   }
 #ifdef DEBUG
   for (int i = 0; i < slot_count;) {
+    DCHECK(spec);
     FeedbackSlotKind kind = spec->GetKind(FeedbackSlot(i));
     int entry_size = FeedbackMetadata::GetSlotSize(kind);
     for (int j = 1; j < entry_size; j++) {
@@ -116,6 +99,7 @@ Handle<FeedbackMetadata> FeedbackMetadata::New(Isolate* isolate,
   Handle<FeedbackMetadata> metadata = Handle<FeedbackMetadata>::cast(array);
 
   for (int i = 0; i < slot_count; i++) {
+    DCHECK(spec);
     FeedbackSlot slot(i);
     FeedbackSlotKind kind = spec->GetKind(slot);
     metadata->SetKind(slot, kind);

src/feedback-vector.h

@@ -300,9 +300,25 @@ class FeedbackVector : public HeapObject {
   DISALLOW_IMPLICIT_CONSTRUCTORS(FeedbackVector);
 };
 
-template <typename Derived>
-class V8_EXPORT_PRIVATE FeedbackVectorSpecBase {
+class V8_EXPORT_PRIVATE FeedbackVectorSpec {
  public:
+  explicit FeedbackVectorSpec(Zone* zone) : slot_kinds_(zone) {
+    slot_kinds_.reserve(16);
+  }
+
+  int slots() const { return static_cast<int>(slot_kinds_.size()); }
+
+  FeedbackSlotKind GetKind(FeedbackSlot slot) const {
+    return static_cast<FeedbackSlotKind>(slot_kinds_.at(slot.ToInt()));
+  }
+
+  bool HasTypeProfileSlot() const;
+
+  // If used, the TypeProfileSlot is always added as the first slot and its
+  // index is constant. If other slots are added before the TypeProfileSlot,
+  // this number changes.
+  static const int kTypeProfileSlotIndex = 0;
+
   FeedbackSlot AddCallICSlot() { return AddSlot(FeedbackSlotKind::kCall); }
 
   FeedbackSlot AddLoadICSlot() {
@@ -380,58 +396,6 @@ class V8_EXPORT_PRIVATE FeedbackVectorSpecBase {
  private:
   FeedbackSlot AddSlot(FeedbackSlotKind kind);
 
-  Derived* This() { return static_cast<Derived*>(this); }
-};
-
-class StaticFeedbackVectorSpec
-    : public FeedbackVectorSpecBase<StaticFeedbackVectorSpec> {
- public:
-  StaticFeedbackVectorSpec() : slot_count_(0) {}
-
-  int slots() const { return slot_count_; }
-
-  FeedbackSlotKind GetKind(FeedbackSlot slot) const {
-    DCHECK(slot.ToInt() >= 0 && slot.ToInt() < slot_count_);
-    return kinds_[slot.ToInt()];
-  }
-
- private:
-  friend class FeedbackVectorSpecBase<StaticFeedbackVectorSpec>;
-
-  void append(FeedbackSlotKind kind) {
-    DCHECK_LT(slot_count_, kMaxLength);
-    kinds_[slot_count_++] = kind;
-  }
-
-  static const int kMaxLength = 12;
-
-  int slot_count_;
-  FeedbackSlotKind kinds_[kMaxLength];
-};
-
-class V8_EXPORT_PRIVATE FeedbackVectorSpec
-    : public FeedbackVectorSpecBase<FeedbackVectorSpec> {
- public:
-  explicit FeedbackVectorSpec(Zone* zone) : slot_kinds_(zone) {
-    slot_kinds_.reserve(16);
-  }
-
-  int slots() const { return static_cast<int>(slot_kinds_.size()); }
-
-  FeedbackSlotKind GetKind(FeedbackSlot slot) const {
-    return static_cast<FeedbackSlotKind>(slot_kinds_.at(slot.ToInt()));
-  }
-
-  bool HasTypeProfileSlot() const;
-
-  // If used, the TypeProfileSlot is always added as the first slot and its
-  // index is constant. If other slots are added before the TypeProfileSlot,
-  // this number changes.
-  static const int kTypeProfileSlotIndex = 0;
-
- private:
-  friend class FeedbackVectorSpecBase<FeedbackVectorSpec>;
-
   void append(FeedbackSlotKind kind) {
     slot_kinds_.push_back(static_cast<unsigned char>(kind));
   }
@@ -466,8 +430,9 @@ class FeedbackMetadata : public FixedArray {
   // Returns slot kind for given slot.
   FeedbackSlotKind GetKind(FeedbackSlot slot) const;
 
-  template <typename Spec>
-  static Handle<FeedbackMetadata> New(Isolate* isolate, const Spec* spec);
+  // If {spec} is null, then it is considered empty.
+  static Handle<FeedbackMetadata> New(Isolate* isolate,
+                                      const FeedbackVectorSpec* spec = nullptr);
 
 #ifdef OBJECT_PRINT
   // For gdb debugging.

src/objects-printer.cc

@@ -688,20 +688,16 @@ void TransitionArray::TransitionArrayPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-template void FeedbackVectorSpecBase<StaticFeedbackVectorSpec>::Print();
-template void FeedbackVectorSpecBase<FeedbackVectorSpec>::Print();
-
-template <typename Derived>
-void FeedbackVectorSpecBase<Derived>::Print() {
+void FeedbackVectorSpec::Print() {
   OFStream os(stdout);
+
   FeedbackVectorSpecPrint(os);
+
   os << std::flush;
 }
 
-template <typename Derived>
-void FeedbackVectorSpecBase<Derived>::FeedbackVectorSpecPrint(
-    std::ostream& os) {  // NOLINT
-  int slot_count = This()->slots();
+void FeedbackVectorSpec::FeedbackVectorSpecPrint(std::ostream& os) {  // NOLINT
+  int slot_count = slots();
   os << " - slot_count: " << slot_count;
   if (slot_count == 0) {
     os << " (empty)\n";
@@ -709,7 +705,7 @@ void FeedbackVectorSpecBase<Derived>::FeedbackVectorSpecPrint(
   }
 
   for (int slot = 0; slot < slot_count;) {
-    FeedbackSlotKind kind = This()->GetKind(FeedbackSlot(slot));
+    FeedbackSlotKind kind = GetKind(FeedbackSlot(slot));
     int entry_size = FeedbackMetadata::GetSlotSize(kind);
     DCHECK_LT(0, entry_size);
     os << "\n Slot #" << slot << " " << kind;