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1 // Copyright 2013 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_NODE_PROPERTIES_H_
6 #define V8_COMPILER_NODE_PROPERTIES_H_
7 
8 #include "src/compiler/node.h"
9 #include "src/compiler/types.h"
10 #include "src/globals.h"
11 #include "src/zone/zone-handle-set.h"
12 
13 namespace v8 {
14 namespace internal {
15 namespace compiler {
16 
17 class Graph;
18 class Operator;
19 class CommonOperatorBuilder;
20 
21 // A facade that simplifies access to the different kinds of inputs to a node.
22 class V8_EXPORT_PRIVATE NodeProperties final {
23  public:
24   // ---------------------------------------------------------------------------
25   // Input layout.
26   // Inputs are always arranged in order as follows:
27   //     0 [ values, context, frame state, effects, control ] node->InputCount()
28 
FirstValueIndex(Node * node)29   static int FirstValueIndex(Node* node) { return 0; }
FirstContextIndex(Node * node)30   static int FirstContextIndex(Node* node) { return PastValueIndex(node); }
FirstFrameStateIndex(Node * node)31   static int FirstFrameStateIndex(Node* node) { return PastContextIndex(node); }
FirstEffectIndex(Node * node)32   static int FirstEffectIndex(Node* node) { return PastFrameStateIndex(node); }
FirstControlIndex(Node * node)33   static int FirstControlIndex(Node* node) { return PastEffectIndex(node); }
34   static int PastValueIndex(Node* node);
35   static int PastContextIndex(Node* node);
36   static int PastFrameStateIndex(Node* node);
37   static int PastEffectIndex(Node* node);
38   static int PastControlIndex(Node* node);
39 
40 
41   // ---------------------------------------------------------------------------
42   // Input accessors.
43 
44   static Node* GetValueInput(Node* node, int index);
45   static Node* GetContextInput(Node* node);
46   static Node* GetFrameStateInput(Node* node);
47   static Node* GetEffectInput(Node* node, int index = 0);
48   static Node* GetControlInput(Node* node, int index = 0);
49 
50 
51   // ---------------------------------------------------------------------------
52   // Edge kinds.
53 
54   static bool IsValueEdge(Edge edge);
55   static bool IsContextEdge(Edge edge);
56   static bool IsFrameStateEdge(Edge edge);
57   static bool IsEffectEdge(Edge edge);
58   static bool IsControlEdge(Edge edge);
59 
60 
61   // ---------------------------------------------------------------------------
62   // Miscellaneous predicates.
63 
IsCommon(Node * node)64   static bool IsCommon(Node* node) {
65     return IrOpcode::IsCommonOpcode(node->opcode());
66   }
IsControl(Node * node)67   static bool IsControl(Node* node) {
68     return IrOpcode::IsControlOpcode(node->opcode());
69   }
IsConstant(Node * node)70   static bool IsConstant(Node* node) {
71     return IrOpcode::IsConstantOpcode(node->opcode());
72   }
IsPhi(Node * node)73   static bool IsPhi(Node* node) {
74     return IrOpcode::IsPhiOpcode(node->opcode());
75   }
76 
77   // Determines whether exceptions thrown by the given node are handled locally
78   // within the graph (i.e. an IfException projection is present).
79   static bool IsExceptionalCall(Node* node);
80 
81   // ---------------------------------------------------------------------------
82   // Miscellaneous mutators.
83 
84   static void ReplaceValueInput(Node* node, Node* value, int index);
85   static void ReplaceContextInput(Node* node, Node* context);
86   static void ReplaceControlInput(Node* node, Node* control, int index = 0);
87   static void ReplaceEffectInput(Node* node, Node* effect, int index = 0);
88   static void ReplaceFrameStateInput(Node* node, Node* frame_state);
89   static void RemoveNonValueInputs(Node* node);
90   static void RemoveValueInputs(Node* node);
91 
92   // Replaces all value inputs of {node} with the single input {value}.
93   static void ReplaceValueInputs(Node* node, Node* value);
94 
95   // Merge the control node {node} into the end of the graph, introducing a
96   // merge node or expanding an existing merge node if necessary.
97   static void MergeControlToEnd(Graph* graph, CommonOperatorBuilder* common,
98                                 Node* node);
99 
100   // Replace all uses of {node} with the given replacement nodes. All occurring
101   // use kinds need to be replaced, {nullptr} is only valid if a use kind is
102   // guaranteed not to exist.
103   static void ReplaceUses(Node* node, Node* value, Node* effect = nullptr,
104                           Node* success = nullptr, Node* exception = nullptr);
105 
106   // Safe wrapper to mutate the operator of a node. Checks that the node is
107   // currently in a state that satisfies constraints of the new operator.
108   static void ChangeOp(Node* node, const Operator* new_op);
109 
110   // ---------------------------------------------------------------------------
111   // Miscellaneous utilities.
112 
113   // Find the last frame state that is effect-wise before the given node. This
114   // assumes a linear effect-chain up to a {CheckPoint} node in the graph.
115   static Node* FindFrameStateBefore(Node* node);
116 
117   // Collect the output-value projection for the given output index.
118   static Node* FindProjection(Node* node, size_t projection_index);
119 
120   // Collect the branch-related projections from a node, such as IfTrue,
121   // IfFalse, IfSuccess, IfException, IfValue and IfDefault.
122   //  - Branch: [ IfTrue, IfFalse ]
123   //  - Call  : [ IfSuccess, IfException ]
124   //  - Switch: [ IfValue, ..., IfDefault ]
125   static void CollectControlProjections(Node* node, Node** proj, size_t count);
126 
127   // Checks if two nodes are the same, looking past {CheckHeapObject}.
128   static bool IsSame(Node* a, Node* b);
129 
130   // Walks up the {effect} chain to find a witness that provides map
131   // information about the {receiver}. Can look through potentially
132   // side effecting nodes.
133   enum InferReceiverMapsResult {
134     kNoReceiverMaps,         // No receiver maps inferred.
135     kReliableReceiverMaps,   // Receiver maps can be trusted.
136     kUnreliableReceiverMaps  // Receiver maps might have changed (side-effect).
137   };
138   static InferReceiverMapsResult InferReceiverMaps(
139       Node* receiver, Node* effect, ZoneHandleSet<Map>* maps_return);
140 
141   // ---------------------------------------------------------------------------
142   // Context.
143 
144   // Try to retrieve the specialization context from the given {node},
145   // optionally utilizing the knowledge about the (outermost) function
146   // {context}.
147   static MaybeHandle<Context> GetSpecializationContext(
148       Node* node, MaybeHandle<Context> context = MaybeHandle<Context>());
149 
150   // Walk up the context chain from the given {node} until we reduce the {depth}
151   // to 0 or hit a node that does not extend the context chain ({depth} will be
152   // updated accordingly).
153   static Node* GetOuterContext(Node* node, size_t* depth);
154 
155   // ---------------------------------------------------------------------------
156   // Type.
157 
IsTyped(Node * node)158   static bool IsTyped(Node* node) { return node->type() != nullptr; }
GetType(Node * node)159   static Type* GetType(Node* node) {
160     DCHECK(IsTyped(node));
161     return node->type();
162   }
163   static Type* GetTypeOrAny(Node* node);
SetType(Node * node,Type * type)164   static void SetType(Node* node, Type* type) {
165     DCHECK_NOT_NULL(type);
166     node->set_type(type);
167   }
RemoveType(Node * node)168   static void RemoveType(Node* node) { node->set_type(nullptr); }
169   static bool AllValueInputsAreTyped(Node* node);
170 
171  private:
172   static inline bool IsInputRange(Edge edge, int first, int count);
173 };
174 
175 }  // namespace compiler
176 }  // namespace internal
177 }  // namespace v8
178 
179 #endif  // V8_COMPILER_NODE_PROPERTIES_H_
180