1 //===- DSGraph.h - Represent a collection of data structures ----*- C++ -*-===//
3 // This header defines the data structure graph.
5 //===----------------------------------------------------------------------===//
7 #ifndef LLVM_ANALYSIS_DSGRAPH_H
8 #define LLVM_ANALYSIS_DSGRAPH_H
10 #include "llvm/Analysis/DSNode.h"
12 //===----------------------------------------------------------------------===//
13 /// DSGraph - The graph that represents a function.
16 Function *Func; // Func - The LLVM function this graph corresponds to
17 DSGraph *GlobalsGraph; // Pointer to the common graph of global objects
19 DSNodeHandle RetNode; // The node that gets returned...
20 std::vector<DSNode*> Nodes;
21 std::map<Value*, DSNodeHandle> ScalarMap;
23 // FunctionCalls - This vector maintains a single entry for each call
24 // instruction in the current graph. The first entry in the vector is the
25 // scalar that holds the return value for the call, the second is the function
26 // scalar being invoked, and the rest are pointer arguments to the function.
27 // This vector is built by the Local graph and is never modified after that.
29 std::vector<DSCallSite> FunctionCalls;
31 // AuxFunctionCalls - This vector contains call sites that have been processed
32 // by some mechanism. In pratice, the BU Analysis uses this vector to hold
33 // the _unresolved_ call sites, because it cannot modify FunctionCalls.
35 std::vector<DSCallSite> AuxFunctionCalls;
37 void operator=(const DSGraph &); // DO NOT IMPLEMENT
39 DSGraph() : Func(0), GlobalsGraph(0) {} // Create a new, empty, DSGraph.
40 DSGraph(Function &F, DSGraph *GlobalsGraph); // Compute the local DSGraph
42 // Copy ctor - If you want to capture the node mapping between the source and
43 // destination graph, you may optionally do this by specifying a map to record
46 // Note that a copied graph does not retain the GlobalsGraph pointer of the
47 // source. You need to set a new GlobalsGraph with the setGlobalsGraph
50 DSGraph(const DSGraph &DSG);
51 DSGraph(const DSGraph &DSG, std::map<const DSNode*, DSNodeHandle> &NodeMap);
54 bool hasFunction() const { return Func != 0; }
55 Function &getFunction() const { return *Func; }
57 DSGraph *getGlobalsGraph() const { return GlobalsGraph; }
58 void setGlobalsGraph(DSGraph *G) { GlobalsGraph = G; }
60 /// getNodes - Get a vector of all the nodes in the graph
62 const std::vector<DSNode*> &getNodes() const { return Nodes; }
63 std::vector<DSNode*> &getNodes() { return Nodes; }
65 /// addNode - Add a new node to the graph.
67 void addNode(DSNode *N) { Nodes.push_back(N); }
69 /// getScalarMap - Get a map that describes what the nodes the scalars in this
70 /// function point to...
72 std::map<Value*, DSNodeHandle> &getScalarMap() { return ScalarMap; }
73 const std::map<Value*, DSNodeHandle> &getScalarMap() const {return ScalarMap;}
75 /// getFunctionCalls - Return the list of call sites in the original local
78 const std::vector<DSCallSite> &getFunctionCalls() const {
82 /// getAuxFunctionCalls - Get the call sites as modified by whatever passes
85 std::vector<DSCallSite> &getAuxFunctionCalls() {
86 return AuxFunctionCalls;
89 /// getNodeForValue - Given a value that is used or defined in the body of the
90 /// current function, return the DSNode that it points to.
92 DSNodeHandle &getNodeForValue(Value *V) { return ScalarMap[V]; }
94 const DSNodeHandle &getNodeForValue(Value *V) const {
95 std::map<Value*, DSNodeHandle>::const_iterator I = ScalarMap.find(V);
96 assert(I != ScalarMap.end() &&
97 "Use non-const lookup function if node may not be in the map");
101 const DSNodeHandle &getRetNode() const { return RetNode; }
102 DSNodeHandle &getRetNode() { return RetNode; }
104 unsigned getGraphSize() const {
108 void print(std::ostream &O) const;
110 void writeGraphToFile(std::ostream &O, const std::string &GraphName) const;
112 /// maskNodeTypes - Apply a mask to all of the node types in the graph. This
113 /// is useful for clearing out markers like Incomplete.
115 void maskNodeTypes(unsigned char Mask) {
116 for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
117 Nodes[i]->NodeType &= Mask;
119 void maskIncompleteMarkers() { maskNodeTypes(~DSNode::Incomplete); }
121 // markIncompleteNodes - Traverse the graph, identifying nodes that may be
122 // modified by other functions that have not been resolved yet. This marks
123 // nodes that are reachable through three sources of "unknownness":
124 // Global Variables, Function Calls, and Incoming Arguments
126 // For any node that may have unknown components (because something outside
127 // the scope of current analysis may have modified it), the 'Incomplete' flag
128 // is added to the NodeType.
130 void markIncompleteNodes(bool markFormalArgs = true);
132 // removeDeadNodes - Use a more powerful reachability analysis to eliminate
133 // subgraphs that are unreachable. This often occurs because the data
134 // structure doesn't "escape" into it's caller, and thus should be eliminated
135 // from the caller's graph entirely. This is only appropriate to use when
138 void removeDeadNodes(bool KeepAllGlobals);
140 // CloneFlags enum - Bits that may be passed into the cloneInto method to
141 // specify how to clone the function graph.
143 StripAllocaBit = 1 << 0, KeepAllocaBit = 0 << 0,
144 DontCloneCallNodes = 1 << 1, CloneCallNodes = 0 << 0,
145 DontCloneAuxCallNodes = 1 << 2, CloneAuxCallNodes = 0 << 0,
148 // cloneInto - Clone the specified DSGraph into the current graph, returning
149 // the Return node of the graph. The translated ScalarMap for the old
150 // function is filled into the OldValMap member. If StripAllocas is set to
151 // 'StripAllocaBit', Alloca markers are removed from the graph as the graph is
154 DSNodeHandle cloneInto(const DSGraph &G,
155 std::map<Value*, DSNodeHandle> &OldValMap,
156 std::map<const DSNode*, DSNodeHandle> &OldNodeMap,
157 unsigned CloneFlags = 0);
159 /// mergeInGraph - The method is used for merging graphs together. If the
160 /// argument graph is not *this, it makes a clone of the specified graph, then
161 /// merges the nodes specified in the call site with the formal arguments in
162 /// the graph. If the StripAlloca's argument is 'StripAllocaBit' then Alloca
163 /// markers are removed from nodes.
165 void mergeInGraph(DSCallSite &CS, const DSGraph &Graph, unsigned CloneFlags);
168 bool isNodeDead(DSNode *N);
170 // removeTriviallyDeadNodes - After the graph has been constructed, this
171 // method removes all unreachable nodes that are created because they got
172 // merged with other nodes in the graph. This is used as the first step of
175 void removeTriviallyDeadNodes(bool KeepAllGlobals = false);