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.
109 // NOTE: Because this clones a dsgraph and returns it, the caller is responsible
110 // for deleting the returned graph!
112 DSGraph *FunctionModRefInfo::ResolveCallSiteModRefInfo(const CallInst &CI) {
113 // Step #1: Clone the top-down graph...
114 DSGraph *Result = new DSGraph(funcTDGraph);
116 //const Function &F = *CI.getParent()->getParent();
117 //DSGraph &TDGraph = IPModRefObj.getAnalysis<TDDataStructures>().getDSGraph(F);
123 // Compute Mod/Ref bit vectors for a single call site.
124 // These are copies of the Read/Write flags from the nodes of
125 // the graph produced by clearing all flags in teh caller's TD graph
126 // and then inlining the callee's BU graph into the caller's TD graph.
129 FunctionModRefInfo::computeModRef(const CallInst& callInst)
131 // Allocate the mod/ref info for the call site. Bits automatically cleared.
132 ModRefInfo* callModRefInfo = new ModRefInfo(funcTDGraph.getGraphSize());
133 callSiteModRefInfo[&callInst] = callModRefInfo;
135 // Get a copy of the graph for the callee with the callee inlined
136 DSGraph* csgp = ResolveCallSiteModRefInfo(callInst);
138 // For all nodes in the graph, extract the mod/ref information
139 const std::vector<DSNode*>& csgNodes = csgp->getNodes();
140 const std::vector<DSNode*>& origNodes = funcTDGraph.getNodes();
141 assert(csgNodes.size() == origNodes.size());
142 for (unsigned i=0, N = csgNodes.size(); i < N; ++i)
144 if (csgNodes[i]->isModified())
145 callModRefInfo->setNodeIsMod(getNodeId(origNodes[i]));
146 if (csgNodes[i]->isRead())
147 callModRefInfo->setNodeIsRef(getNodeId(origNodes[i]));
153 // Print the results of the pass.
154 // Currently this just prints bit-vectors and is not very readable.
156 void FunctionModRefInfo::print(std::ostream &O) const
158 O << "---------- Mod/ref information for function "
159 << F.getName() << "---------- \n\n";
161 O << "Mod/ref info for function body:\n";
162 funcModRefInfo.print(O);
164 for (std::map<const CallInst*, ModRefInfo*>::const_iterator
165 CI = callSiteModRefInfo.begin(), CE = callSiteModRefInfo.end();
168 O << "Mod/ref info for call site " << CI->first << ":\n";
169 CI->second->print(O);
175 void FunctionModRefInfo::dump() const
181 //----------------------------------------------------------------------------
182 // class IPModRef: An interprocedural pass that computes IP Mod/Ref info.
183 //----------------------------------------------------------------------------
186 // Free the FunctionModRefInfo objects cached in funcToModRefInfoMap.
188 void IPModRef::releaseMemory()
190 for(std::map<const Function*, FunctionModRefInfo*>::iterator
191 I=funcToModRefInfoMap.begin(), E=funcToModRefInfoMap.end(); I != E; ++I)
194 // Clear map so memory is not re-released if we are called again
195 funcToModRefInfoMap.clear();
199 // Run the "interprocedural" pass on each function. This needs to do
200 // NO real interprocedural work because all that has been done the
201 // data structure analysis.
203 bool IPModRef::run(Module &theModule)
206 for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
207 if (! FI->isExternal())
208 getFuncInfo(*FI, /*computeIfMissing*/ true);
213 FunctionModRefInfo& IPModRef::getFuncInfo(const Function& func,
214 bool computeIfMissing)
216 FunctionModRefInfo*& funcInfo = funcToModRefInfoMap[&func];
217 assert (funcInfo != NULL || computeIfMissing);
218 if (funcInfo == NULL)
219 { // Create a new FunctionModRefInfo object
220 funcInfo = new FunctionModRefInfo(func, *this, // inserts into map
221 getAnalysis<TDDataStructures>().getDSGraph(func),
222 getAnalysis<LocalDataStructures>().getDSGraph(func));
223 funcInfo->computeModRef(func); // computes the mod/ref info
228 // getAnalysisUsage - This pass requires top-down data structure graphs.
229 // It modifies nothing.
231 void IPModRef::getAnalysisUsage(AnalysisUsage &AU) const {
232 AU.setPreservesAll();
233 AU.addRequired<LocalDataStructures>();
234 AU.addRequired<BUDataStructures>();
235 AU.addRequired<TDDataStructures>();
239 void IPModRef::print(std::ostream &O) const
241 O << "\n========== Results of Interprocedural Mod/Ref Analysis ==========\n";
243 for (std::map<const Function*, FunctionModRefInfo*>::const_iterator
244 mapI = funcToModRefInfoMap.begin(), mapE = funcToModRefInfoMap.end();
245 mapI != mapE; ++mapI)
246 mapI->second->print(O);
252 void IPModRef::dump() const