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 #include "src/compiler/js-graph.h"
6 #include "src/compiler/node-properties-inl.h"
7 #include "src/compiler/typer.h"
8 
9 namespace v8 {
10 namespace internal {
11 namespace compiler {
12 
ImmovableHeapConstant(Handle<Object> object)13 Node* JSGraph::ImmovableHeapConstant(Handle<Object> object) {
14   Unique<Object> unique = Unique<Object>::CreateImmovable(object);
15   return NewNode(common()->HeapConstant(unique));
16 }
17 
18 
NewNode(const Operator * op)19 Node* JSGraph::NewNode(const Operator* op) {
20   Node* node = graph()->NewNode(op);
21   typer_->Init(node);
22   return node;
23 }
24 
25 
CEntryStubConstant()26 Node* JSGraph::CEntryStubConstant() {
27   if (!c_entry_stub_constant_.is_set()) {
28     c_entry_stub_constant_.set(
29         ImmovableHeapConstant(CEntryStub(isolate(), 1).GetCode()));
30   }
31   return c_entry_stub_constant_.get();
32 }
33 
34 
UndefinedConstant()35 Node* JSGraph::UndefinedConstant() {
36   if (!undefined_constant_.is_set()) {
37     undefined_constant_.set(
38         ImmovableHeapConstant(factory()->undefined_value()));
39   }
40   return undefined_constant_.get();
41 }
42 
43 
TheHoleConstant()44 Node* JSGraph::TheHoleConstant() {
45   if (!the_hole_constant_.is_set()) {
46     the_hole_constant_.set(ImmovableHeapConstant(factory()->the_hole_value()));
47   }
48   return the_hole_constant_.get();
49 }
50 
51 
TrueConstant()52 Node* JSGraph::TrueConstant() {
53   if (!true_constant_.is_set()) {
54     true_constant_.set(ImmovableHeapConstant(factory()->true_value()));
55   }
56   return true_constant_.get();
57 }
58 
59 
FalseConstant()60 Node* JSGraph::FalseConstant() {
61   if (!false_constant_.is_set()) {
62     false_constant_.set(ImmovableHeapConstant(factory()->false_value()));
63   }
64   return false_constant_.get();
65 }
66 
67 
NullConstant()68 Node* JSGraph::NullConstant() {
69   if (!null_constant_.is_set()) {
70     null_constant_.set(ImmovableHeapConstant(factory()->null_value()));
71   }
72   return null_constant_.get();
73 }
74 
75 
ZeroConstant()76 Node* JSGraph::ZeroConstant() {
77   if (!zero_constant_.is_set()) zero_constant_.set(NumberConstant(0.0));
78   return zero_constant_.get();
79 }
80 
81 
OneConstant()82 Node* JSGraph::OneConstant() {
83   if (!one_constant_.is_set()) one_constant_.set(NumberConstant(1.0));
84   return one_constant_.get();
85 }
86 
87 
NaNConstant()88 Node* JSGraph::NaNConstant() {
89   if (!nan_constant_.is_set()) {
90     nan_constant_.set(NumberConstant(base::OS::nan_value()));
91   }
92   return nan_constant_.get();
93 }
94 
95 
HeapConstant(Unique<Object> value)96 Node* JSGraph::HeapConstant(Unique<Object> value) {
97   // TODO(turbofan): canonicalize heap constants using Unique<T>
98   return NewNode(common()->HeapConstant(value));
99 }
100 
101 
HeapConstant(Handle<Object> value)102 Node* JSGraph::HeapConstant(Handle<Object> value) {
103   // TODO(titzer): We could also match against the addresses of immortable
104   // immovables here, even without access to the heap, thus always
105   // canonicalizing references to them.
106   // return HeapConstant(Unique<Object>::CreateUninitialized(value));
107   // TODO(turbofan): This is a work-around to make Unique::HashCode() work for
108   // value numbering. We need some sane way to compute a unique hash code for
109   // arbitrary handles here.
110   Unique<Object> unique(reinterpret_cast<Address>(*value.location()), value);
111   return HeapConstant(unique);
112 }
113 
114 
Constant(Handle<Object> value)115 Node* JSGraph::Constant(Handle<Object> value) {
116   // Dereference the handle to determine if a number constant or other
117   // canonicalized node can be used.
118   if (value->IsNumber()) {
119     return Constant(value->Number());
120   } else if (value->IsUndefined()) {
121     return UndefinedConstant();
122   } else if (value->IsTrue()) {
123     return TrueConstant();
124   } else if (value->IsFalse()) {
125     return FalseConstant();
126   } else if (value->IsNull()) {
127     return NullConstant();
128   } else if (value->IsTheHole()) {
129     return TheHoleConstant();
130   } else {
131     return HeapConstant(value);
132   }
133 }
134 
135 
Constant(double value)136 Node* JSGraph::Constant(double value) {
137   if (bit_cast<int64_t>(value) == bit_cast<int64_t>(0.0)) return ZeroConstant();
138   if (bit_cast<int64_t>(value) == bit_cast<int64_t>(1.0)) return OneConstant();
139   return NumberConstant(value);
140 }
141 
142 
Constant(int32_t value)143 Node* JSGraph::Constant(int32_t value) {
144   if (value == 0) return ZeroConstant();
145   if (value == 1) return OneConstant();
146   return NumberConstant(value);
147 }
148 
149 
Int32Constant(int32_t value)150 Node* JSGraph::Int32Constant(int32_t value) {
151   Node** loc = cache_.FindInt32Constant(value);
152   if (*loc == NULL) {
153     *loc = NewNode(common()->Int32Constant(value));
154   }
155   return *loc;
156 }
157 
158 
NumberConstant(double value)159 Node* JSGraph::NumberConstant(double value) {
160   Node** loc = cache_.FindNumberConstant(value);
161   if (*loc == NULL) {
162     *loc = NewNode(common()->NumberConstant(value));
163   }
164   return *loc;
165 }
166 
167 
Float64Constant(double value)168 Node* JSGraph::Float64Constant(double value) {
169   Node** loc = cache_.FindFloat64Constant(value);
170   if (*loc == NULL) {
171     *loc = NewNode(common()->Float64Constant(value));
172   }
173   return *loc;
174 }
175 
176 
ExternalConstant(ExternalReference reference)177 Node* JSGraph::ExternalConstant(ExternalReference reference) {
178   Node** loc = cache_.FindExternalConstant(reference);
179   if (*loc == NULL) {
180     *loc = NewNode(common()->ExternalConstant(reference));
181   }
182   return *loc;
183 }
184 }  // namespace compiler
185 }  // namespace internal
186 }  // namespace v8
187