Move of the type feedback vector to the closure.

src/objects.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 9892 matching lines @@
   Handle<FixedArray> result;
   if (number_of_deopt_points == 0) {
     result = isolate->factory()->empty_fixed_array();
   } else {
     result = isolate->factory()->NewFixedArray(
         LengthOfFixedArray(number_of_deopt_points), pretenure);
   }
   return Handle<DeoptimizationOutputData>::cast(result);
 }
 
+const int LiteralsArray::kFeedbackVectorOffset =
+    LiteralsArray::OffsetOfElementAt(LiteralsArray::kVectorIndex);
+
+const int LiteralsArray::kOffsetToFirstLiteral =
+    LiteralsArray::OffsetOfElementAt(LiteralsArray::kFirstLiteralIndex);
 
 // static
 Handle<LiteralsArray> LiteralsArray::New(Isolate* isolate,
                                          Handle<TypeFeedbackVector> vector,
                                          int number_of_literals,
                                          PretenureFlag pretenure) {
+  if (vector->is_empty() && number_of_literals == 0) {
+    return Handle<LiteralsArray>::cast(
+        isolate->factory()->empty_literals_array());
+  }
   Handle<FixedArray> literals = isolate->factory()->NewFixedArray(
       number_of_literals + kFirstLiteralIndex, pretenure);
   Handle<LiteralsArray> casted_literals = Handle<LiteralsArray>::cast(literals);
   casted_literals->set_feedback_vector(*vector);
   return casted_literals;
 }
 
 int HandlerTable::LookupRange(int pc_offset, int* data_out,
                               CatchPrediction* prediction_out) {
   int innermost_handler = -1;
@@ skipping 1360 matching lines @@
   if (FLAG_trace_concurrent_recompilation) {
     PrintF("  ** Marking ");
     ShortPrint();
     PrintF(" for concurrent recompilation.\n");
   }
   set_code_no_write_barrier(
       isolate->builtins()->builtin(Builtins::kCompileOptimizedConcurrent));
   // No write barrier required, since the builtin is part of the root set.
 }
 
+// static
+Handle<LiteralsArray> SharedFunctionInfo::FindOrCreateLiterals(
+    Handle<SharedFunctionInfo> shared, Handle<Context> native_context) {
+  Isolate* isolate = shared->GetIsolate();
+  CodeAndLiterals result =
+      shared->SearchOptimizedCodeMap(*native_context, BailoutId::None());
+  if (result.literals != nullptr) {
+    DCHECK(shared->feedback_metadata()->is_empty() ||
+           !result.literals->feedback_vector()->is_empty());
+    return handle(result.literals, isolate);
+  }
+
+  Handle<TypeFeedbackVector> feedback_vector =
+      TypeFeedbackVector::New(isolate, handle(shared->feedback_metadata()));
+  Handle<LiteralsArray> literals = LiteralsArray::New(
+      isolate, feedback_vector, shared->num_literals(), TENURED);
+  Handle<Code> code;
+  if (result.code != nullptr) {
+    code = Handle<Code>(result.code, isolate);
+  }
+  AddToOptimizedCodeMap(shared, native_context, code, literals,
+                        BailoutId::None());
+  return literals;
+}
 
 void SharedFunctionInfo::AddSharedCodeToOptimizedCodeMap(
     Handle<SharedFunctionInfo> shared, Handle<Code> code) {
   Isolate* isolate = shared->GetIsolate();
   if (isolate->serializer_enabled()) return;
   DCHECK(code->kind() == Code::OPTIMIZED_FUNCTION);
   // Empty code maps are unsupported.
   if (!shared->OptimizedCodeMapIsCleared()) {
     Handle<WeakCell> cell = isolate->factory()->NewWeakCell(code);
     // A collection may have occured and cleared the optimized code map in the
@@ skipping 176 matching lines @@
   DCHECK(shrink_by <= code_map->length() - kEntriesStart);
   // Always trim even when array is cleared because of heap verifier.
   GetHeap()->RightTrimFixedArray<Heap::SEQUENTIAL_TO_SWEEPER>(code_map,
                                                               shrink_by);
   if (code_map->length() == kEntriesStart &&
       WeakCell::cast(code_map->get(kSharedCodeIndex))->cleared()) {
     ClearOptimizedCodeMap();
   }
 }
 
+// static
+void JSFunction::EnsureLiterals(Handle<JSFunction> function) {
+  Handle<SharedFunctionInfo> shared(function->shared());
+  Handle<Context> native_context(function->context()->native_context());
+  if (function->literals() ==
+      function->GetIsolate()->heap()->empty_literals_array()) {
+    Handle<LiteralsArray> literals =
+        SharedFunctionInfo::FindOrCreateLiterals(shared, native_context);
+    function->set_literals(*literals);
+  }
+}
 
 static void GetMinInobjectSlack(Map* map, void* data) {
   int slack = map->unused_property_fields();
   if (*reinterpret_cast<int*>(data) > slack) {
     *reinterpret_cast<int*>(data) = slack;
   }
 }
 
 
 static void ShrinkInstanceSize(Map* map, void* data) {
@@ skipping 1410 matching lines @@
   if (isolate->serializer_enabled()) return;
 
   if (unused_property_fields() == 0) return;
 
   set_construction_counter(Map::kSlackTrackingCounterStart);
 }
 
 
 void SharedFunctionInfo::ResetForNewContext(int new_ic_age) {
   code()->ClearInlineCaches();
-  // If we clear ICs, we need to clear the type feedback vector too, since
-  // CallICs are synced with a feedback vector slot.
-  ClearTypeFeedbackInfo();
   set_ic_age(new_ic_age);
   if (code()->kind() == Code::FUNCTION) {
     code()->set_profiler_ticks(0);
     if (optimization_disabled() && opt_count() >= FLAG_max_opt_count) {
       // Re-enable optimizations if they were disabled due to opt_count limit.
       set_optimization_disabled(false);
     }
     set_opt_count(0);
     set_deopt_count(0);
   } else if (code()->is_interpreter_trampoline_builtin()) {
@@ skipping 25 matching lines @@
     }
     Object* shared_code =
         WeakCell::cast(optimized_code_map->get(kSharedCodeIndex))->value();
     if (shared_code->IsCode() && osr_ast_id.IsNone()) {
       return kSharedCodeIndex;
     }
   }
   return -1;
 }
 
+void SharedFunctionInfo::ClearCodeFromOptimizedCodeMap() {
+  if (!OptimizedCodeMapIsCleared()) {
+    FixedArray* optimized_code_map = this->optimized_code_map();
+    int length = optimized_code_map->length();
+    WeakCell* empty_weak_cell = GetHeap()->empty_weak_cell();
+    for (int i = kEntriesStart; i < length; i += kEntryLength) {
+      optimized_code_map->set(i + kCachedCodeOffset, empty_weak_cell,
+                              SKIP_WRITE_BARRIER);
+    }
+    optimized_code_map->set(kSharedCodeIndex, empty_weak_cell,
+                            SKIP_WRITE_BARRIER);
+  }
+}
 
 CodeAndLiterals SharedFunctionInfo::SearchOptimizedCodeMap(
     Context* native_context, BailoutId osr_ast_id) {
   CodeAndLiterals result = {nullptr, nullptr};
   int entry = SearchOptimizedCodeMapEntry(native_context, osr_ast_id);
   if (entry != kNotFound) {
     FixedArray* code_map = optimized_code_map();
     if (entry == kSharedCodeIndex) {
       // We know the weak cell isn't cleared because we made sure of it in
       // SearchOptimizedCodeMapEntry and performed no allocations since that
@@ skipping 314 matching lines @@
 int AbstractCode::SourcePosition(int offset) {
   return IsBytecodeArray() ? GetBytecodeArray()->SourcePosition(offset)
                            : GetCode()->SourcePosition(offset);
 }
 
 int AbstractCode::SourceStatementPosition(int offset) {
   return IsBytecodeArray() ? GetBytecodeArray()->SourceStatementPosition(offset)
                            : GetCode()->SourceStatementPosition(offset);
 }
 
-void SharedFunctionInfo::ClearTypeFeedbackInfo() {
-  feedback_vector()->ClearSlots(this);
+void JSFunction::ClearTypeFeedbackInfo() {
+  feedback_vector()->ClearSlots(shared());
 }
 
-
-void SharedFunctionInfo::ClearTypeFeedbackInfoAtGCTime() {
-  feedback_vector()->ClearSlotsAtGCTime(this);
+void JSFunction::ClearTypeFeedbackInfoAtGCTime() {
+  feedback_vector()->ClearSlotsAtGCTime(shared());
 }
 
-
 BailoutId Code::TranslatePcOffsetToAstId(uint32_t pc_offset) {
   DisallowHeapAllocation no_gc;
   DCHECK(kind() == FUNCTION);
   BackEdgeTable back_edges(this, &no_gc);
   for (uint32_t i = 0; i < back_edges.length(); i++) {
     if (back_edges.pc_offset(i) == pc_offset) return back_edges.ast_id(i);
   }
   return BailoutId::None();
 }
 
@@ skipping 5114 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8