Line data    Source code

       1             : // Copyright 2014 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_COMPILER_JS_CONTEXT_SPECIALIZATION_H_
       6             : #define V8_COMPILER_JS_CONTEXT_SPECIALIZATION_H_
       7             : 
       8             : #include "src/compiler/graph-reducer.h"
       9             : #include "src/maybe-handles.h"
      10             : 
      11             : namespace v8 {
      12             : namespace internal {
      13             : namespace compiler {
      14             : 
      15             : // Forward declarations.
      16             : class JSGraph;
      17             : class JSOperatorBuilder;
      18             : 
      19             : // Pair of a context and its distance from some point of reference.
      20             : struct OuterContext {
      21       26518 :   OuterContext() = default;
      22             :   OuterContext(Handle<Context> context_, size_t distance_)
      23             :       : context(context_), distance(distance_) {}
      24             : 
      25             :   Handle<Context> context;
      26             :   size_t distance = 0;
      27             : };
      28             : 
      29             : // Specializes a given JSGraph to a given context, potentially constant folding
      30             : // some {LoadContext} nodes or strength reducing some {StoreContext} nodes.
      31             : // Additionally, constant-folds the function parameter if {closure} is given.
      32             : //
      33             : // The context can be the incoming function context or any outer context
      34             : // thereof, as indicated by {outer}'s {distance}.
      35      928288 : class V8_EXPORT_PRIVATE JSContextSpecialization final : public AdvancedReducer {
      36             :  public:
      37             :   JSContextSpecialization(Editor* editor, JSGraph* jsgraph,
      38             :                           JSHeapBroker* broker, Maybe<OuterContext> outer,
      39             :                           MaybeHandle<JSFunction> closure)
      40             :       : AdvancedReducer(editor),
      41             :         jsgraph_(jsgraph),
      42             :         outer_(outer),
      43             :         closure_(closure),
      44      464143 :         broker_(broker) {}
      45             : 
      46          19 :   const char* reducer_name() const override {
      47          19 :     return "JSContextSpecialization";
      48             :   }
      49             : 
      50             :   Reduction Reduce(Node* node) final;
      51             : 
      52             :  private:
      53             :   Reduction ReduceParameter(Node* node);
      54             :   Reduction ReduceJSLoadContext(Node* node);
      55             :   Reduction ReduceJSStoreContext(Node* node);
      56             : 
      57             :   Reduction SimplifyJSStoreContext(Node* node, Node* new_context,
      58             :                                    size_t new_depth);
      59             :   Reduction SimplifyJSLoadContext(Node* node, Node* new_context,
      60             :                                   size_t new_depth);
      61             : 
      62             :   Isolate* isolate() const;
      63             :   JSGraph* jsgraph() const { return jsgraph_; }
      64      877854 :   Maybe<OuterContext> outer() const { return outer_; }
      65             :   MaybeHandle<JSFunction> closure() const { return closure_; }
      66             :   JSHeapBroker* broker() const { return broker_; }
      67             : 
      68             :   JSGraph* const jsgraph_;
      69             :   Maybe<OuterContext> outer_;
      70             :   MaybeHandle<JSFunction> closure_;
      71             :   JSHeapBroker* const broker_;
      72             : 
      73             :   DISALLOW_COPY_AND_ASSIGN(JSContextSpecialization);
      74             : };
      75             : 
      76             : }  // namespace compiler
      77             : }  // namespace internal
      78             : }  // namespace v8
      79             : 
      80             : #endif  // V8_COMPILER_JS_CONTEXT_SPECIALIZATION_H_