1 //===- DSGraph.h - Represent a collection of data structures ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header defines the data structure graph (DSGraph) and the
11 // ReachabilityCloner class.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_ANALYSIS_DSGRAPH_H
16 #define LLVM_ANALYSIS_DSGRAPH_H
18 #include "llvm/Analysis/DataStructure/DSNode.h"
24 //===----------------------------------------------------------------------===//
25 /// DSScalarMap - An instance of this class is used to keep track of all of
26 /// which DSNode each scalar in a function points to. This is specialized to
27 /// keep track of globals with nodes in the function, and to keep track of the
28 /// unique DSNodeHandle being used by the scalar map.
30 /// This class is crucial to the efficiency of DSA with some large SCC's. In
31 /// these cases, the cost of iterating over the scalar map dominates the cost
32 /// of DSA. In all of these cases, the DSA phase is really trying to identify
33 /// globals or unique node handles active in the function.
36 typedef hash_map<Value*, DSNodeHandle> ValueMapTy;
39 typedef hash_set<GlobalValue*> GlobalSetTy;
40 GlobalSetTy GlobalSet;
43 // Compatibility methods: provide an interface compatible with a map of
44 // Value* to DSNodeHandle's.
45 typedef ValueMapTy::const_iterator const_iterator;
46 typedef ValueMapTy::iterator iterator;
47 iterator begin() { return ValueMap.begin(); }
48 iterator end() { return ValueMap.end(); }
49 const_iterator begin() const { return ValueMap.begin(); }
50 const_iterator end() const { return ValueMap.end(); }
51 iterator find(Value *V) { return ValueMap.find(V); }
52 const_iterator find(Value *V) const { return ValueMap.find(V); }
53 unsigned count(Value *V) const { return ValueMap.count(V); }
55 void erase(Value *V) { erase(find(V)); }
57 /// replaceScalar - When an instruction needs to be modified, this method can
58 /// be used to update the scalar map to remove the old and insert the new.
60 void replaceScalar(Value *Old, Value *New) {
61 iterator I = find(Old);
62 assert(I != end() && "Old value is not in the map!");
63 ValueMap.insert(std::make_pair(New, I->second));
67 DSNodeHandle &operator[](Value *V) {
68 std::pair<iterator,bool> IP =
69 ValueMap.insert(std::make_pair(V, DSNodeHandle()));
70 if (IP.second) { // Inserted the new entry into the map.
71 if (GlobalValue *GV = dyn_cast<GlobalValue>(V))
74 return IP.first->second;
77 void erase(iterator I) {
78 assert(I != ValueMap.end() && "Cannot erase end!");
79 if (GlobalValue *GV = dyn_cast<GlobalValue>(I->first))
89 // Access to the global set: the set of all globals currently in the
91 typedef GlobalSetTy::const_iterator global_iterator;
92 global_iterator global_begin() const { return GlobalSet.begin(); }
93 global_iterator global_end() const { return GlobalSet.end(); }
97 //===----------------------------------------------------------------------===//
98 /// DSGraph - The graph that represents a function.
101 // Public data-type declarations...
102 typedef DSScalarMap ScalarMapTy;
103 typedef hash_map<Function*, DSNodeHandle> ReturnNodesTy;
104 typedef hash_set<GlobalValue*> GlobalSetTy;
105 typedef ilist<DSNode> NodeListTy;
107 /// NodeMapTy - This data type is used when cloning one graph into another to
108 /// keep track of the correspondence between the nodes in the old and new
110 typedef hash_map<const DSNode*, DSNodeHandle> NodeMapTy;
112 DSGraph *GlobalsGraph; // Pointer to the common graph of global objects
113 bool PrintAuxCalls; // Should this graph print the Aux calls vector?
116 ScalarMapTy ScalarMap;
118 // ReturnNodes - A return value for every function merged into this graph.
119 // Each DSGraph may have multiple functions merged into it at any time, which
120 // is used for representing SCCs.
122 ReturnNodesTy ReturnNodes;
124 // FunctionCalls - This vector maintains a single entry for each call
125 // instruction in the current graph. The first entry in the vector is the
126 // scalar that holds the return value for the call, the second is the function
127 // scalar being invoked, and the rest are pointer arguments to the function.
128 // This vector is built by the Local graph and is never modified after that.
130 std::vector<DSCallSite> FunctionCalls;
132 // AuxFunctionCalls - This vector contains call sites that have been processed
133 // by some mechanism. In pratice, the BU Analysis uses this vector to hold
134 // the _unresolved_ call sites, because it cannot modify FunctionCalls.
136 std::vector<DSCallSite> AuxFunctionCalls;
138 // InlinedGlobals - This set records which globals have been inlined from
139 // other graphs (callers or callees, depending on the pass) into this one.
141 GlobalSetTy InlinedGlobals;
143 /// TD - This is the target data object for the machine this graph is
145 const TargetData &TD;
147 void operator=(const DSGraph &); // DO NOT IMPLEMENT
150 // Create a new, empty, DSGraph.
151 DSGraph(const TargetData &td)
152 : GlobalsGraph(0), PrintAuxCalls(false), TD(td) {}
154 // Compute the local DSGraph
155 DSGraph(const TargetData &td, Function &F, DSGraph *GlobalsGraph);
157 // Copy ctor - If you want to capture the node mapping between the source and
158 // destination graph, you may optionally do this by specifying a map to record
161 // Note that a copied graph does not retain the GlobalsGraph pointer of the
162 // source. You need to set a new GlobalsGraph with the setGlobalsGraph
165 DSGraph(const DSGraph &DSG);
166 DSGraph(const DSGraph &DSG, NodeMapTy &NodeMap);
169 DSGraph *getGlobalsGraph() const { return GlobalsGraph; }
170 void setGlobalsGraph(DSGraph *G) { GlobalsGraph = G; }
172 /// getTargetData - Return the TargetData object for the current target.
174 const TargetData &getTargetData() const { return TD; }
176 /// setPrintAuxCalls - If you call this method, the auxillary call vector will
177 /// be printed instead of the standard call vector to the dot file.
179 void setPrintAuxCalls() { PrintAuxCalls = true; }
180 bool shouldPrintAuxCalls() const { return PrintAuxCalls; }
182 /// node_iterator/begin/end - Iterate over all of the nodes in the graph. Be
183 /// extremely careful with these methods because any merging of nodes could
184 /// cause the node to be removed from this list. This means that if you are
185 /// iterating over nodes and doing something that could cause _any_ node to
186 /// merge, your node_iterators into this graph can be invalidated.
187 typedef NodeListTy::compat_iterator node_iterator;
188 node_iterator node_begin() const { return Nodes.compat_begin(); }
189 node_iterator node_end() const { return Nodes.compat_end(); }
191 /// getFunctionNames - Return a space separated list of the name of the
192 /// functions in this graph (if any)
194 std::string getFunctionNames() const;
196 /// addNode - Add a new node to the graph.
198 void addNode(DSNode *N) { Nodes.push_back(N); }
199 void unlinkNode(DSNode *N) { Nodes.remove(N); }
201 /// getScalarMap - Get a map that describes what the nodes the scalars in this
202 /// function point to...
204 ScalarMapTy &getScalarMap() { return ScalarMap; }
205 const ScalarMapTy &getScalarMap() const { return ScalarMap; }
207 /// getFunctionCalls - Return the list of call sites in the original local
210 const std::vector<DSCallSite> &getFunctionCalls() const {
211 return FunctionCalls;
214 /// getAuxFunctionCalls - Get the call sites as modified by whatever passes
217 std::vector<DSCallSite> &getAuxFunctionCalls() {
218 return AuxFunctionCalls;
220 const std::vector<DSCallSite> &getAuxFunctionCalls() const {
221 return AuxFunctionCalls;
224 /// getInlinedGlobals - Get the set of globals that are have been inlined
225 /// (from callees in BU or from callers in TD) into the current graph.
227 GlobalSetTy& getInlinedGlobals() {
228 return InlinedGlobals;
231 /// getNodeForValue - Given a value that is used or defined in the body of the
232 /// current function, return the DSNode that it points to.
234 DSNodeHandle &getNodeForValue(Value *V) { return ScalarMap[V]; }
236 const DSNodeHandle &getNodeForValue(Value *V) const {
237 ScalarMapTy::const_iterator I = ScalarMap.find(V);
238 assert(I != ScalarMap.end() &&
239 "Use non-const lookup function if node may not be in the map");
243 /// getReturnNodes - Return the mapping of functions to their return nodes for
246 const ReturnNodesTy &getReturnNodes() const { return ReturnNodes; }
247 ReturnNodesTy &getReturnNodes() { return ReturnNodes; }
249 /// getReturnNodeFor - Return the return node for the specified function.
251 DSNodeHandle &getReturnNodeFor(Function &F) {
252 ReturnNodesTy::iterator I = ReturnNodes.find(&F);
253 assert(I != ReturnNodes.end() && "F not in this DSGraph!");
257 const DSNodeHandle &getReturnNodeFor(Function &F) const {
258 ReturnNodesTy::const_iterator I = ReturnNodes.find(&F);
259 assert(I != ReturnNodes.end() && "F not in this DSGraph!");
263 /// getGraphSize - Return the number of nodes in this graph.
265 unsigned getGraphSize() const {
269 /// print - Print a dot graph to the specified ostream...
271 void print(std::ostream &O) const;
273 /// dump - call print(std::cerr), for use from the debugger...
277 /// viewGraph - Emit a dot graph, run 'dot', run gv on the postscript file,
278 /// then cleanup. For use from the debugger.
280 void viewGraph() const;
282 void writeGraphToFile(std::ostream &O, const std::string &GraphName) const;
284 /// maskNodeTypes - Apply a mask to all of the node types in the graph. This
285 /// is useful for clearing out markers like Incomplete.
287 void maskNodeTypes(unsigned Mask) {
288 for (node_iterator I = node_begin(), E = node_end(); I != E; ++I)
289 (*I)->maskNodeTypes(Mask);
291 void maskIncompleteMarkers() { maskNodeTypes(~DSNode::Incomplete); }
293 // markIncompleteNodes - Traverse the graph, identifying nodes that may be
294 // modified by other functions that have not been resolved yet. This marks
295 // nodes that are reachable through three sources of "unknownness":
296 // Global Variables, Function Calls, and Incoming Arguments
298 // For any node that may have unknown components (because something outside
299 // the scope of current analysis may have modified it), the 'Incomplete' flag
300 // is added to the NodeType.
302 enum MarkIncompleteFlags {
303 MarkFormalArgs = 1, IgnoreFormalArgs = 0,
304 IgnoreGlobals = 2, MarkGlobalsIncomplete = 0,
306 void markIncompleteNodes(unsigned Flags);
308 // removeDeadNodes - Use a reachability analysis to eliminate subgraphs that
309 // are unreachable. This often occurs because the data structure doesn't
310 // "escape" into it's caller, and thus should be eliminated from the caller's
311 // graph entirely. This is only appropriate to use when inlining graphs.
313 enum RemoveDeadNodesFlags {
314 RemoveUnreachableGlobals = 1, KeepUnreachableGlobals = 0,
316 void removeDeadNodes(unsigned Flags);
318 /// CloneFlags enum - Bits that may be passed into the cloneInto method to
319 /// specify how to clone the function graph.
321 StripAllocaBit = 1 << 0, KeepAllocaBit = 0,
322 DontCloneCallNodes = 1 << 1, CloneCallNodes = 0,
323 DontCloneAuxCallNodes = 1 << 2, CloneAuxCallNodes = 0,
324 StripModRefBits = 1 << 3, KeepModRefBits = 0,
325 StripIncompleteBit = 1 << 4, KeepIncompleteBit = 0,
326 UpdateInlinedGlobals = 1 << 5, DontUpdateInlinedGlobals = 0,
329 void updateFromGlobalGraph();
331 /// computeNodeMapping - Given roots in two different DSGraphs, traverse the
332 /// nodes reachable from the two graphs, computing the mapping of nodes from
333 /// the first to the second graph.
335 static void computeNodeMapping(const DSNodeHandle &NH1,
336 const DSNodeHandle &NH2, NodeMapTy &NodeMap,
337 bool StrictChecking = true);
340 /// cloneInto - Clone the specified DSGraph into the current graph. The
341 /// translated ScalarMap for the old function is filled into the OldValMap
342 /// member, and the translated ReturnNodes map is returned into ReturnNodes.
343 /// OldNodeMap contains a mapping from the original nodes to the newly cloned
346 /// The CloneFlags member controls various aspects of the cloning process.
348 void cloneInto(const DSGraph &G, ScalarMapTy &OldValMap,
349 ReturnNodesTy &OldReturnNodes, NodeMapTy &OldNodeMap,
350 unsigned CloneFlags = 0);
352 /// mergeInGraph - The method is used for merging graphs together. If the
353 /// argument graph is not *this, it makes a clone of the specified graph, then
354 /// merges the nodes specified in the call site with the formal arguments in
355 /// the graph. If the StripAlloca's argument is 'StripAllocaBit' then Alloca
356 /// markers are removed from nodes.
358 void mergeInGraph(const DSCallSite &CS, Function &F, const DSGraph &Graph,
359 unsigned CloneFlags);
361 /// getCallSiteForArguments - Get the arguments and return value bindings for
362 /// the specified function in the current graph.
364 DSCallSite getCallSiteForArguments(Function &F) const;
366 /// getDSCallSiteForCallSite - Given an LLVM CallSite object that is live in
367 /// the context of this graph, return the DSCallSite for it.
368 DSCallSite getDSCallSiteForCallSite(CallSite CS) const;
370 // Methods for checking to make sure graphs are well formed...
371 void AssertNodeInGraph(const DSNode *N) const {
372 assert((!N || N->getParentGraph() == this) &&
373 "AssertNodeInGraph: Node is not in graph!");
375 void AssertNodeContainsGlobal(const DSNode *N, GlobalValue *GV) const {
376 assert(std::find(N->getGlobals().begin(), N->getGlobals().end(), GV) !=
377 N->getGlobals().end() && "Global value not in node!");
380 void AssertCallSiteInGraph(const DSCallSite &CS) const;
381 void AssertCallNodesInGraph() const;
382 void AssertAuxCallNodesInGraph() const;
384 void AssertGraphOK() const;
386 /// removeTriviallyDeadNodes - After the graph has been constructed, this
387 /// method removes all unreachable nodes that are created because they got
388 /// merged with other nodes in the graph. This is used as the first step of
391 void removeTriviallyDeadNodes();
395 /// ReachabilityCloner - This class is used to incrementally clone and merge
396 /// nodes from a non-changing source graph into a potentially mutating
397 /// destination graph. Nodes are only cloned over on demand, either in
398 /// responds to a merge() or getClonedNH() call. When a node is cloned over,
399 /// all of the nodes reachable from it are automatically brought over as well.
401 class ReachabilityCloner {
405 /// BitsToKeep - These bits are retained from the source node when the
406 /// source nodes are merged into the destination graph.
410 // NodeMap - A mapping from nodes in the source graph to the nodes that
411 // represent them in the destination graph.
412 DSGraph::NodeMapTy NodeMap;
414 ReachabilityCloner(DSGraph &dest, const DSGraph &src, unsigned cloneFlags)
415 : Dest(dest), Src(src), CloneFlags(cloneFlags) {
416 assert(&Dest != &Src && "Cannot clone from graph to same graph!");
417 BitsToKeep = ~DSNode::DEAD;
418 if (CloneFlags & DSGraph::StripAllocaBit)
419 BitsToKeep &= ~DSNode::AllocaNode;
420 if (CloneFlags & DSGraph::StripModRefBits)
421 BitsToKeep &= ~(DSNode::Modified | DSNode::Read);
422 if (CloneFlags & DSGraph::StripIncompleteBit)
423 BitsToKeep &= ~DSNode::Incomplete;
426 DSNodeHandle getClonedNH(const DSNodeHandle &SrcNH);
428 void merge(const DSNodeHandle &NH, const DSNodeHandle &SrcNH);
430 /// mergeCallSite - Merge the nodes reachable from the specified src call
431 /// site into the nodes reachable from DestCS.
433 void mergeCallSite(const DSCallSite &DestCS, const DSCallSite &SrcCS);
435 bool clonedAnyNodes() const { return !NodeMap.empty(); }
437 /// hasClonedNode - Return true if the specified node has been cloned from
438 /// the source graph into the destination graph.
439 bool hasClonedNode(const DSNode *N) {
440 return NodeMap.count(N);
443 void destroy() { NodeMap.clear(); }
446 } // End llvm namespace