1 //===-- llvm/Support/DataFlow.h - dataflow as graphs ------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines specializations of GraphTraits that allows Use-Def and
11 // Def-Use relations to be treated as proper graphs for generic algorithms.
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_SUPPORT_DATAFLOW_H
15 #define LLVM_SUPPORT_DATAFLOW_H
16 
17 #include "llvm/User.h"
18 #include "llvm/ADT/GraphTraits.h"
19 
20 namespace llvm {
21 
22 //===----------------------------------------------------------------------===//
23 // Provide specializations of GraphTraits to be able to treat def-use/use-def
24 // chains as graphs
25 
26 template <> struct GraphTraits<const Value*> {
27   typedef const Value NodeType;
28   typedef Value::const_use_iterator ChildIteratorType;
29 
30   static NodeType *getEntryNode(const Value *G) {
31     return G;
32   }
33 
34   static inline ChildIteratorType child_begin(NodeType *N) {
35     return N->use_begin();
36   }
37 
38   static inline ChildIteratorType child_end(NodeType *N) {
39     return N->use_end();
40   }
41 };
42 
43 template <> struct GraphTraits<Value*> {
44   typedef Value NodeType;
45   typedef Value::use_iterator ChildIteratorType;
46 
47   static NodeType *getEntryNode(Value *G) {
48     return G;
49   }
50 
51   static inline ChildIteratorType child_begin(NodeType *N) {
52     return N->use_begin();
53   }
54 
55   static inline ChildIteratorType child_end(NodeType *N) {
56     return N->use_end();
57   }
58 };
59 
60 template <> struct GraphTraits<Inverse<const User*> > {
61   typedef const Value NodeType;
62   typedef User::const_op_iterator ChildIteratorType;
63 
64   static NodeType *getEntryNode(Inverse<const User*> G) {
65     return G.Graph;
66   }
67 
68   static inline ChildIteratorType child_begin(NodeType *N) {
69     if (const User *U = dyn_cast<User>(N))
70       return U->op_begin();
71     return NULL;
72   }
73 
74   static inline ChildIteratorType child_end(NodeType *N) {
75     if(const User *U = dyn_cast<User>(N))
76       return U->op_end();
77     return NULL;
78   }
79 };
80 
81 template <> struct GraphTraits<Inverse<User*> > {
82   typedef Value NodeType;
83   typedef User::op_iterator ChildIteratorType;
84 
85   static NodeType *getEntryNode(Inverse<User*> G) {
86     return G.Graph;
87   }
88 
89   static inline ChildIteratorType child_begin(NodeType *N) {
90     if (User *U = dyn_cast<User>(N))
91       return U->op_begin();
92     return NULL;
93   }
94 
95   static inline ChildIteratorType child_end(NodeType *N) {
96     if (User *U = dyn_cast<User>(N))
97       return U->op_end();
98     return NULL;
99   }
100 };
101 
102 }
103 #endif
104