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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_MACHINE_OPERATOR_REDUCER_H_
6 #define V8_COMPILER_MACHINE_OPERATOR_REDUCER_H_
7 
8 #include "src/base/compiler-specific.h"
9 #include "src/common/globals.h"
10 #include "src/compiler/graph-reducer.h"
11 #include "src/compiler/machine-operator.h"
12 
13 namespace v8 {
14 namespace internal {
15 namespace compiler {
16 
17 // Forward declarations.
18 class CommonOperatorBuilder;
19 class MachineGraph;
20 class Word32Adapter;
21 class Word64Adapter;
22 
23 // Performs constant folding and strength reduction on nodes that have
24 // machine operators.
25 class V8_EXPORT_PRIVATE MachineOperatorReducer final
NON_EXPORTED_BASE(AdvancedReducer)26     : public NON_EXPORTED_BASE(AdvancedReducer) {
27  public:
28   explicit MachineOperatorReducer(Editor* editor, MachineGraph* mcgraph,
29                                   bool allow_signalling_nan = true);
30   ~MachineOperatorReducer() override;
31 
32   const char* reducer_name() const override { return "MachineOperatorReducer"; }
33 
34   Reduction Reduce(Node* node) override;
35 
36  private:
37   friend class Word32Adapter;
38   friend class Word64Adapter;
39 
40   Node* Float32Constant(volatile float value);
41   Node* Float64Constant(volatile double value);
42   Node* Int32Constant(int32_t value);
43   Node* Int64Constant(int64_t value);
44   Node* Uint32Constant(uint32_t value) {
45     return Int32Constant(bit_cast<int32_t>(value));
46   }
47   Node* Uint64Constant(uint64_t value) {
48     return Int64Constant(bit_cast<int64_t>(value));
49   }
50   Node* Float64Mul(Node* lhs, Node* rhs);
51   Node* Float64PowHalf(Node* value);
52   Node* Word32And(Node* lhs, Node* rhs);
53   Node* Word32And(Node* lhs, uint32_t rhs) {
54     return Word32And(lhs, Uint32Constant(rhs));
55   }
56   Node* Word32Sar(Node* lhs, uint32_t rhs);
57   Node* Word32Shr(Node* lhs, uint32_t rhs);
58   Node* Word32Equal(Node* lhs, Node* rhs);
59   Node* Word64And(Node* lhs, Node* rhs);
60   Node* Int32Add(Node* lhs, Node* rhs);
61   Node* Int32Sub(Node* lhs, Node* rhs);
62   Node* Int32Mul(Node* lhs, Node* rhs);
63   Node* Int32Div(Node* dividend, int32_t divisor);
64   Node* Uint32Div(Node* dividend, uint32_t divisor);
65   Node* TruncateInt64ToInt32(Node* value);
66 
67   Reduction ReplaceBool(bool value) { return ReplaceInt32(value ? 1 : 0); }
68   Reduction ReplaceFloat32(volatile float value) {
69     return Replace(Float32Constant(value));
70   }
71   Reduction ReplaceFloat64(volatile double value) {
72     return Replace(Float64Constant(value));
73   }
74   Reduction ReplaceInt32(int32_t value) {
75     return Replace(Int32Constant(value));
76   }
77   Reduction ReplaceUint32(uint32_t value) {
78     return Replace(Uint32Constant(value));
79   }
80   Reduction ReplaceInt64(int64_t value) {
81     return Replace(Int64Constant(value));
82   }
83 
84   Reduction ReduceInt32Add(Node* node);
85   Reduction ReduceInt64Add(Node* node);
86   Reduction ReduceInt32Sub(Node* node);
87   Reduction ReduceInt64Sub(Node* node);
88   Reduction ReduceInt64Mul(Node* node);
89   Reduction ReduceInt32Div(Node* node);
90   Reduction ReduceUint32Div(Node* node);
91   Reduction ReduceInt32Mod(Node* node);
92   Reduction ReduceUint32Mod(Node* node);
93   Reduction ReduceStore(Node* node);
94   Reduction ReduceProjection(size_t index, Node* node);
95   const Operator* Map64To32Comparison(const Operator* op, bool sign_extended);
96   Reduction ReduceWord32Comparisons(Node* node);
97   Reduction ReduceWord64Comparisons(Node* node);
98   Reduction ReduceWord32Shifts(Node* node);
99   Reduction ReduceWord32Shl(Node* node);
100   Reduction ReduceWord64Shl(Node* node);
101   Reduction ReduceWord32Shr(Node* node);
102   Reduction ReduceWord64Shr(Node* node);
103   Reduction ReduceWord32Sar(Node* node);
104   Reduction ReduceWord64Sar(Node* node);
105   Reduction ReduceWord32And(Node* node);
106   Reduction ReduceWord64And(Node* node);
107   Reduction TryMatchWord32Ror(Node* node);
108   Reduction ReduceWord32Or(Node* node);
109   Reduction ReduceWord64Or(Node* node);
110   Reduction ReduceWord32Xor(Node* node);
111   Reduction ReduceWord64Xor(Node* node);
112   Reduction ReduceWord32Equal(Node* node);
113   Reduction ReduceFloat64InsertLowWord32(Node* node);
114   Reduction ReduceFloat64InsertHighWord32(Node* node);
115   Reduction ReduceFloat64Compare(Node* node);
116   Reduction ReduceFloat64RoundDown(Node* node);
117   Reduction ReduceTruncateInt64ToInt32(Node* node);
118   Reduction ReduceConditional(Node* node);
119 
120   Graph* graph() const;
121   MachineGraph* mcgraph() const { return mcgraph_; }
122   CommonOperatorBuilder* common() const;
123   MachineOperatorBuilder* machine() const;
124 
125   // These reductions can be applied to operations of different word sizes.
126   // Use Word32Adapter or Word64Adapter to specialize for a particular one.
127   template <typename WordNAdapter>
128   Reduction ReduceWordNAnd(Node* node);
129   template <typename WordNAdapter>
130   Reduction ReduceWordNOr(Node* node);
131   template <typename WordNAdapter>
132   Reduction ReduceWordNXor(Node* node);
133 
134   // Tries to simplify "if(x == 0)" by removing the "== 0" and inverting
135   // branches.
136   Reduction SimplifyBranch(Node* node);
137   // Helper for SimplifyBranch; swaps the if/else of a branch.
138   void SwapBranches(Node* node);
139 
140   // Helper for ReduceConditional. Does not perform the actual reduction; just
141   // returns a new Node that could be used as the input to the condition.
142   template <typename WordNAdapter>
143   base::Optional<Node*> ReduceConditionalN(Node* node);
144 
145   // Helper for finding a reduced equality condition. Does not perform the
146   // actual reduction; just returns a new pair that could be compared for the
147   // same outcome.
148   template <typename WordNAdapter>
149   base::Optional<std::pair<Node*, uint32_t>> ReduceWord32EqualForConstantRhs(
150       Node* lhs, uint32_t rhs);
151 
152   MachineGraph* mcgraph_;
153   bool allow_signalling_nan_;
154 };
155 
156 }  // namespace compiler
157 }  // namespace internal
158 }  // namespace v8
159 
160 #endif  // V8_COMPILER_MACHINE_OPERATOR_REDUCER_H_
161