1 //===- IPModRef.cpp - Compute IP Mod/Ref information ------------*- C++ -*-===//
3 // See high-level comments in include/llvm/Analysis/IPModRef.h
5 //===----------------------------------------------------------------------===//
7 #include "llvm/Analysis/IPModRef.h"
8 #include "llvm/Analysis/DataStructure.h"
9 #include "llvm/Analysis/DSGraph.h"
10 #include "llvm/Module.h"
11 #include "llvm/iOther.h"
12 #include "Support/Statistic.h"
13 #include "Support/STLExtras.h"
14 #include "Support/StringExtras.h"
16 //----------------------------------------------------------------------------
17 // Private constants and data
18 //----------------------------------------------------------------------------
20 static RegisterAnalysis<IPModRef>
21 Z("ipmodref", "Interprocedural mod/ref analysis");
24 //----------------------------------------------------------------------------
26 //----------------------------------------------------------------------------
28 void ModRefInfo::print(std::ostream &O) const
30 O << std::endl << "Modified nodes = " << modNodeSet;
31 O << "Referenced nodes = " << refNodeSet << std::endl;
34 void ModRefInfo::dump() const
39 //----------------------------------------------------------------------------
40 // class FunctionModRefInfo
41 //----------------------------------------------------------------------------
44 // This constructor computes a node numbering for the TD graph.
46 FunctionModRefInfo::FunctionModRefInfo(const Function& func,
50 : F(func), IPModRefObj(ipmro),
53 funcModRefInfo(tdg.getGraphSize())
55 for (unsigned i=0, N = funcTDGraph.getGraphSize(); i < N; ++i)
56 NodeIds[funcTDGraph.getNodes()[i]] = i;
60 FunctionModRefInfo::~FunctionModRefInfo()
62 for(std::map<const CallInst*, ModRefInfo*>::iterator
63 I=callSiteModRefInfo.begin(), E=callSiteModRefInfo.end(); I != E; ++I)
66 // Empty map just to make problems easier to track down
67 callSiteModRefInfo.clear();
70 unsigned FunctionModRefInfo::getNodeId(const Value* value) const {
71 return getNodeId(funcTDGraph.getNodeForValue(const_cast<Value*>(value))
77 // Compute Mod/Ref bit vectors for the entire function.
78 // These are simply copies of the Read/Write flags from the nodes of
79 // the top-down DS graph.
81 void FunctionModRefInfo::computeModRef(const Function &func)
83 // Mark all nodes in the graph that are marked MOD as being mod
84 // and all those marked REF as being ref.
85 for (unsigned i = 0, N = funcTDGraph.getGraphSize(); i < N; ++i)
87 if (funcTDGraph.getNodes()[i]->isModified())
88 funcModRefInfo.setNodeIsMod(i);
89 if (funcTDGraph.getNodes()[i]->isRead())
90 funcModRefInfo.setNodeIsRef(i);
93 // Compute the Mod/Ref info for all call sites within the function
94 // Use the Local DSgraph, which includes all the call sites in the
96 const std::vector<DSCallSite>& callSites = funcLocalGraph.getFunctionCalls();
97 for (unsigned i = 0, N = callSites.size(); i < N; ++i)
98 computeModRef(callSites[i].getCallInst());
101 // ResolveCallSiteModRefInfo - This method performs the following actions:
103 // 1. It clones the top-down graph for the current function
104 // 2. It clears all of the mod/ref bits in the cloned graph
105 // 3. It then merges the bottom-up graph(s) for the specified call-site into
106 // the clone (bringing new mod/ref bits).
107 // 4. It returns the clone, and a mapping of nodes from the original TDGraph to
108 // the cloned graph with Mod/Ref info for the callsite.
110 // NOTE: Because this clones a dsgraph and returns it, the caller is responsible
111 // for deleting the returned graph!
113 DSGraph *FunctionModRefInfo::ResolveCallSiteModRefInfo(const CallInst &CI,
114 std::map<const DSNode*, DSNodeHandle> &NodeMap) {
116 // Step #1: Clone the top-down graph...
117 std::map<const DSNode*, DSNode*> RawNodeMap;
118 DSGraph *Result = new DSGraph(funcTDGraph, RawNodeMap);
120 // Convert the NodeMap from a map to DSNode* to be a map to DSNodeHandle's
121 NodeMap.insert(RawNodeMap.begin(), RawNodeMap.end());
123 // We are now done with the old map... so free it's memory...
126 // Step #2: Clear Mod/Ref information...
127 Result->maskNodeTypes(~(DSNode::Modified | DSNode::Read));
134 // Compute Mod/Ref bit vectors for a single call site.
135 // These are copies of the Read/Write flags from the nodes of
136 // the graph produced by clearing all flags in teh caller's TD graph
137 // and then inlining the callee's BU graph into the caller's TD graph.
140 FunctionModRefInfo::computeModRef(const CallInst& callInst)
142 // Allocate the mod/ref info for the call site. Bits automatically cleared.
143 ModRefInfo* callModRefInfo = new ModRefInfo(funcTDGraph.getGraphSize());
144 callSiteModRefInfo[&callInst] = callModRefInfo;
146 // Get a copy of the graph for the callee with the callee inlined
147 std::map<const DSNode*, DSNodeHandle> NodeMap;
148 DSGraph* csgp = ResolveCallSiteModRefInfo(callInst, NodeMap);
150 // For all nodes in the graph, extract the mod/ref information
151 const std::vector<DSNode*>& csgNodes = csgp->getNodes();
152 const std::vector<DSNode*>& origNodes = funcTDGraph.getNodes();
153 assert(csgNodes.size() == origNodes.size());
154 for (unsigned i=0, N = csgNodes.size(); i < N; ++i)
156 if (csgNodes[i]->isModified())
157 callModRefInfo->setNodeIsMod(getNodeId(origNodes[i]));
158 if (csgNodes[i]->isRead())
159 callModRefInfo->setNodeIsRef(getNodeId(origNodes[i]));
162 // Drop nodemap before we delete the graph...
168 // Print the results of the pass.
169 // Currently this just prints bit-vectors and is not very readable.
171 void FunctionModRefInfo::print(std::ostream &O) const
173 O << "---------- Mod/ref information for function "
174 << F.getName() << "---------- \n\n";
176 O << "Mod/ref info for function body:\n";
177 funcModRefInfo.print(O);
179 for (std::map<const CallInst*, ModRefInfo*>::const_iterator
180 CI = callSiteModRefInfo.begin(), CE = callSiteModRefInfo.end();
183 O << "Mod/ref info for call site " << CI->first << ":\n";
184 CI->second->print(O);
190 void FunctionModRefInfo::dump() const
196 //----------------------------------------------------------------------------
197 // class IPModRef: An interprocedural pass that computes IP Mod/Ref info.
198 //----------------------------------------------------------------------------
200 // Free the FunctionModRefInfo objects cached in funcToModRefInfoMap.
202 void IPModRef::releaseMemory()
204 for(std::map<const Function*, FunctionModRefInfo*>::iterator
205 I=funcToModRefInfoMap.begin(), E=funcToModRefInfoMap.end(); I != E; ++I)
208 // Clear map so memory is not re-released if we are called again
209 funcToModRefInfoMap.clear();
213 // Run the "interprocedural" pass on each function. This needs to do
214 // NO real interprocedural work because all that has been done the
215 // data structure analysis.
217 bool IPModRef::run(Module &theModule)
221 for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
222 if (! FI->isExternal())
223 getFuncInfo(*FI, /*computeIfMissing*/ true);
228 FunctionModRefInfo& IPModRef::getFuncInfo(const Function& func,
229 bool computeIfMissing)
231 FunctionModRefInfo*& funcInfo = funcToModRefInfoMap[&func];
232 assert (funcInfo != NULL || computeIfMissing);
233 if (funcInfo == NULL)
234 { // Create a new FunctionModRefInfo object
235 funcInfo = new FunctionModRefInfo(func, *this, // inserts into map
236 getAnalysis<TDDataStructures>().getDSGraph(func),
237 getAnalysis<LocalDataStructures>().getDSGraph(func));
238 funcInfo->computeModRef(func); // computes the mod/ref info
243 // getAnalysisUsage - This pass requires top-down data structure graphs.
244 // It modifies nothing.
246 void IPModRef::getAnalysisUsage(AnalysisUsage &AU) const {
247 AU.setPreservesAll();
248 AU.addRequired<LocalDataStructures>();
249 AU.addRequired<BUDataStructures>();
250 AU.addRequired<TDDataStructures>();
254 void IPModRef::print(std::ostream &O) const
256 O << "\n========== Results of Interprocedural Mod/Ref Analysis ==========\n";
258 for (std::map<const Function*, FunctionModRefInfo*>::const_iterator
259 mapI = funcToModRefInfoMap.begin(), mapE = funcToModRefInfoMap.end();
260 mapI != mapE; ++mapI)
261 mapI->second->print(O);
267 void IPModRef::dump() const