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