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 | 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 | 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 | broker_(broker) {} |
45 | |
46 | const char* reducer_name() const override { |
47 | 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 | 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_ |
81 | |