[ic] Refactor LoadGlobalIC in preparation for handler inlining

src/ic/accessor-assembler.h

 // Copyright 2016 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.
 
 #ifndef V8_SRC_IC_ACCESSOR_ASSEMBLER_H_
 #define V8_SRC_IC_ACCESSOR_ASSEMBLER_H_
 
 #include "src/code-stub-assembler.h"
 
 namespace v8 {
 namespace internal {
 
 namespace compiler {
 class CodeAssemblerState;
 }
 
+class ExitPoint;
+
 class AccessorAssembler : public CodeStubAssembler {
  public:
   typedef compiler::Node Node;
 
   explicit AccessorAssembler(compiler::CodeAssemblerState* state)
       : CodeStubAssembler(state) {}
 
   void GenerateLoadIC();
   void GenerateLoadField();
   void GenerateLoadICTrampoline();
@@ skipping 15 matching lines @@
                          Label* if_handler, Variable* var_handler,
                          Label* if_miss);
 
   Node* StubCachePrimaryOffsetForTesting(Node* name, Node* map) {
     return StubCachePrimaryOffset(name, map);
   }
   Node* StubCacheSecondaryOffsetForTesting(Node* name, Node* map) {
     return StubCacheSecondaryOffset(name, map);
   }
 
- protected:
   struct LoadICParameters {
     LoadICParameters(Node* context, Node* receiver, Node* name, Node* slot,
                      Node* vector)
         : context(context),
           receiver(receiver),
           name(name),
           slot(slot),
           vector(vector) {}
 
     Node* context;
     Node* receiver;
     Node* name;
     Node* slot;
     Node* vector;
   };
 
+  void LoadGlobalICData(const LoadICParameters* p, ExitPoint* exit_point,
+                        Label* try_handler, Label* miss);
+  void LoadGlobalICHandler(const LoadICParameters* p, TypeofMode typeof_mode,
+                           ExitPoint* exit_point, Label* miss);
+  void LoadGlobalICMiss(const LoadICParameters* p, ExitPoint* exit_point);
+
+ protected:
   struct StoreICParameters : public LoadICParameters {
     StoreICParameters(Node* context, Node* receiver, Node* name, Node* value,
                       Node* slot, Node* vector)
         : LoadICParameters(context, receiver, name, slot, vector),
           value(value) {}
     Node* value;
   };
 
   enum ElementSupport { kOnlyProperties, kSupportElements };
   void HandleStoreICHandlerCase(
@@ skipping 28 matching lines @@
                                        Label* if_miss);
 
   // LoadIC implementation.
 
   void HandleLoadICHandlerCase(
       const LoadICParameters* p, Node* handler, Label* miss,
       ElementSupport support_elements = kOnlyProperties);
 
   void HandleLoadICSmiHandlerCase(const LoadICParameters* p, Node* holder,
                                   Node* smi_handler, Label* miss,
+                                  ExitPoint* exit_point,
                                   ElementSupport support_elements);
 
   void HandleLoadICProtoHandlerCase(const LoadICParameters* p, Node* handler,
                                     Variable* var_holder,
                                     Variable* var_smi_handler,
                                     Label* if_smi_handler, Label* miss,
+                                    ExitPoint* exit_point,
                                     bool throw_reference_error_if_nonexistent);
 
   Node* EmitLoadICProtoArrayCheck(const LoadICParameters* p, Node* handler,
                                   Node* handler_length, Node* handler_flags,
                                   Label* miss,
                                   bool throw_reference_error_if_nonexistent);
 
   // LoadGlobalIC implementation.
 
   void HandleLoadGlobalICHandlerCase(const LoadICParameters* p, Node* handler,
-                                     Label* miss,
+                                     Label* miss, ExitPoint* exit_point,
                                      bool throw_reference_error_if_nonexistent);
 
   // StoreIC implementation.
 
   void HandleStoreICElementHandlerCase(const StoreICParameters* p,
                                        Node* handler, Label* miss);
 
   void HandleStoreICProtoHandler(const StoreICParameters* p, Node* handler,
                                  Label* miss);
   // If |transition| is nullptr then the normal field store is generated or
@@ skipping 28 matching lines @@
                        Representation representation, Node* value,
                        bool transition_to_field);
 
   void EmitFastElementsBoundsCheck(Node* object, Node* elements,
                                    Node* intptr_index,
                                    Node* is_jsarray_condition, Label* miss);
   void EmitElementLoad(Node* object, Node* elements, Node* elements_kind,
                        Node* key, Node* is_jsarray_condition, Label* if_hole,
                        Label* rebox_double, Variable* var_double_value,
                        Label* unimplemented_elements_kind, Label* out_of_bounds,
-                       Label* miss);
+                       Label* miss, ExitPoint* exit_point);
   void CheckPrototype(Node* prototype_cell, Node* name, Label* miss);
   void NameDictionaryNegativeLookup(Node* object, Node* name, Label* miss);
 
   // Stub cache access helpers.
 
   // This enum is used here as a replacement for StubCache::Table to avoid
   // including stub cache header.
   enum StubCacheTable : int;
 
   Node* StubCachePrimaryOffset(Node* name, Node* map);
   Node* StubCacheSecondaryOffset(Node* name, Node* seed);
 
   void TryProbeStubCacheTable(StubCache* stub_cache, StubCacheTable table_id,
                               Node* entry_offset, Node* name, Node* map,
                               Label* if_handler, Variable* var_handler,
                               Label* if_miss);
 };
 
+// Abstraction over direct and indirect exit points. Direct exits correspond to
+// tailcalls and Return, while indirect exits store the result in a variable
+// and then jump to an exit label.
+class ExitPoint {
+ private:
+  typedef compiler::Node Node;
+  typedef compiler::CodeAssemblerLabel CodeAssemblerLabel;
+  typedef compiler::CodeAssemblerVariable CodeAssemblerVariable;
+
+ public:
+  explicit ExitPoint(CodeStubAssembler* assembler)
+      : ExitPoint(assembler, nullptr, nullptr) {}
+  ExitPoint(CodeStubAssembler* assembler, CodeAssemblerLabel* out,
+            CodeAssemblerVariable* var_result)
+      : out_(out), var_result_(var_result), asm_(assembler) {
+    DCHECK(out_ != nullptr || var_result_ == nullptr);

[Igor Sheludko, 2017/02/08 15:26:32]

DCHECK_EQ(out != nullptr, var_result != nullptr);

[jgruber, 2017/02/09 09:23:42]

Done.

+  }
+
+  template <class... TArgs>
+  void ReturnRuntime(Runtime::FunctionId function, Node* context,

[Igor Sheludko, 2017/02/08 15:26:32]

ReturnCallRuntime

[jgruber, 2017/02/09 09:23:42]

Done.

+                     TArgs... args) {
+    if (IsDirect()) {
+      asm_->TailCallRuntime(function, context, args...);
+    } else {
+      IndirectReturn(asm_->CallRuntime(function, context, args...));
+    }
+  }
+
+  template <class... TArgs>
+  void ReturnStub(Callable const& callable, Node* context, TArgs... args) {

[Igor Sheludko, 2017/02/08 15:26:32]

ReturnCallStub

[jgruber, 2017/02/09 09:23:42]

Done.

+    if (IsDirect()) {
+      asm_->TailCallStub(callable, context, args...);
+    } else {
+      IndirectReturn(asm_->CallStub(callable, context, args...));
+    }
+  }
+
+  template <class... TArgs>
+  void ReturnStub(const CallInterfaceDescriptor& descriptor, Node* target,

[Igor Sheludko, 2017/02/08 15:26:32]

ReturnCallStub

[jgruber, 2017/02/09 09:23:42]

Done.

+                  Node* context, TArgs... args) {
+    if (IsDirect()) {
+      asm_->TailCallStub(descriptor, target, context, args...);
+    } else {
+      IndirectReturn(asm_->CallStub(descriptor, target, context, args...));
+    }
+  }
+
+  void Return(Node* const result) {
+    if (IsDirect()) {
+      asm_->Return(result);
+    } else {
+      IndirectReturn(result);
+    }
+  }
+
+  bool IsDirect() const { return out_ == nullptr; }
+  bool IsIndirect() const { return !IsDirect(); }

[Igor Sheludko, 2017/02/08 15:26:32]

I'd just leave IsDirect()

[jgruber, 2017/02/09 09:23:42]

Done.

+
+ private:
+  void IndirectReturn(Node* const result) {
+    var_result_->Bind(result);
+    asm_->Goto(out_);
+  }
+
+  CodeAssemblerLabel* const out_;
+  CodeAssemblerVariable* const var_result_;
+  CodeStubAssembler* const asm_;
+};
+
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_SRC_IC_ACCESSOR_ASSEMBLER_H_