1 //===- CompleteBottomUp.cpp - Complete Bottom-Up Data Structure Graphs ----===//
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 is the exact same as the bottom-up graphs, but we use take a completed
11 // call graph and inline all indirect callees into their callers graphs, making
12 // the result more useful for things like pool allocation.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Analysis/DataStructure.h"
17 #include "llvm/Module.h"
18 #include "llvm/Analysis/DSGraph.h"
19 #include "Support/Debug.h"
20 #include "Support/SCCIterator.h"
21 #include "Support/Statistic.h"
22 #include "Support/STLExtras.h"
26 RegisterAnalysis<CompleteBUDataStructures>
27 X("cbudatastructure", "'Complete' Bottom-up Data Structure Analysis");
28 Statistic<> NumCBUInlines("cbudatastructures", "Number of graphs inlined");
32 // run - Calculate the bottom up data structure graphs for each function in the
35 bool CompleteBUDataStructures::run(Module &M) {
36 BUDataStructures &BU = getAnalysis<BUDataStructures>();
37 GlobalsGraph = new DSGraph(BU.getGlobalsGraph());
38 GlobalsGraph->setPrintAuxCalls();
40 // Our call graph is the same as the BU data structures call graph
41 ActualCallees = BU.getActualCallees();
43 #if 1 // REMOVE ME EVENTUALLY
44 // FIXME: TEMPORARY (remove once finalization of indirect call sites in the
45 // globals graph has been implemented in the BU pass)
46 TDDataStructures &TD = getAnalysis<TDDataStructures>();
48 // The call graph extractable from the TD pass is _much more complete_ and
49 // trustable than that generated by the BU pass so far. Until this is fixed,
50 // we hack it like this:
51 for (Module::iterator MI = M.begin(), ME = M.end(); MI != ME; ++MI) {
52 if (MI->isExternal()) continue;
53 const std::vector<DSCallSite> &CSs = TD.getDSGraph(*MI).getFunctionCalls();
55 for (unsigned CSi = 0, e = CSs.size(); CSi != e; ++CSi) {
56 if (CSs[CSi].isIndirectCall()) {
57 Instruction *TheCall = CSs[CSi].getCallSite().getInstruction();
59 const std::vector<GlobalValue*> &Callees =
60 CSs[CSi].getCalleeNode()->getGlobals();
61 for (unsigned i = 0, e = Callees.size(); i != e; ++i)
62 if (Function *F = dyn_cast<Function>(Callees[i]))
63 ActualCallees.insert(std::make_pair(TheCall, F));
69 std::vector<DSGraph*> Stack;
70 hash_map<DSGraph*, unsigned> ValMap;
73 if (Function *Main = M.getMainFunction()) {
74 calculateSCCGraphs(getOrCreateGraph(*Main), Stack, NextID, ValMap);
76 std::cerr << "CBU-DSA: No 'main' function found!\n";
79 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
80 if (!I->isExternal() && !DSInfo.count(I))
81 calculateSCCGraphs(getOrCreateGraph(*I), Stack, NextID, ValMap);
83 GlobalsGraph->removeTriviallyDeadNodes();
87 DSGraph &CompleteBUDataStructures::getOrCreateGraph(Function &F) {
88 // Has the graph already been created?
89 DSGraph *&Graph = DSInfo[&F];
90 if (Graph) return *Graph;
92 // Copy the BU graph...
93 Graph = new DSGraph(getAnalysis<BUDataStructures>().getDSGraph(F));
94 Graph->setGlobalsGraph(GlobalsGraph);
95 Graph->setPrintAuxCalls();
97 // Make sure to update the DSInfo map for all of the functions currently in
99 for (DSGraph::ReturnNodesTy::iterator I = Graph->getReturnNodes().begin();
100 I != Graph->getReturnNodes().end(); ++I)
101 DSInfo[I->first] = Graph;
108 unsigned CompleteBUDataStructures::calculateSCCGraphs(DSGraph &FG,
109 std::vector<DSGraph*> &Stack,
111 hash_map<DSGraph*, unsigned> &ValMap) {
112 assert(!ValMap.count(&FG) && "Shouldn't revisit functions!");
113 unsigned Min = NextID++, MyID = Min;
115 Stack.push_back(&FG);
117 // The edges out of the current node are the call site targets...
118 for (unsigned i = 0, e = FG.getFunctionCalls().size(); i != e; ++i) {
119 Instruction *Call = FG.getFunctionCalls()[i].getCallSite().getInstruction();
121 // Loop over all of the actually called functions...
122 ActualCalleesTy::iterator I, E;
123 for (tie(I, E) = ActualCallees.equal_range(Call); I != E; ++I)
124 if (!I->second->isExternal()) {
125 DSGraph &Callee = getOrCreateGraph(*I->second);
127 // Have we visited the destination function yet?
128 hash_map<DSGraph*, unsigned>::iterator It = ValMap.find(&Callee);
129 if (It == ValMap.end()) // No, visit it now.
130 M = calculateSCCGraphs(Callee, Stack, NextID, ValMap);
131 else // Yes, get it's number.
133 if (M < Min) Min = M;
137 assert(ValMap[&FG] == MyID && "SCC construction assumption wrong!");
139 return Min; // This is part of a larger SCC!
141 // If this is a new SCC, process it now.
142 bool IsMultiNodeSCC = false;
143 while (Stack.back() != &FG) {
144 DSGraph *NG = Stack.back();
147 DSGraph::NodeMapTy NodeMap;
148 FG.cloneInto(*NG, FG.getScalarMap(), FG.getReturnNodes(), NodeMap);
150 // Update the DSInfo map and delete the old graph...
151 for (DSGraph::ReturnNodesTy::iterator I = NG->getReturnNodes().begin();
152 I != NG->getReturnNodes().end(); ++I)
153 DSInfo[I->first] = &FG;
157 IsMultiNodeSCC = true;
160 // Clean up the graph before we start inlining a bunch again...
162 FG.removeTriviallyDeadNodes();
171 /// processGraph - Process the BU graphs for the program in bottom-up order on
172 /// the SCC of the __ACTUAL__ call graph. This builds "complete" BU graphs.
173 void CompleteBUDataStructures::processGraph(DSGraph &G) {
174 hash_set<Instruction*> calls;
176 // The edges out of the current node are the call site targets...
177 for (unsigned i = 0, e = G.getFunctionCalls().size(); i != e; ++i) {
178 const DSCallSite &CS = G.getFunctionCalls()[i];
179 Instruction *TheCall = CS.getCallSite().getInstruction();
181 assert(calls.insert(TheCall).second &&
182 "Call instruction occurs multiple times in graph??");
185 // The Normal BU pass will have taken care of direct calls well already,
186 // don't worry about them.
188 // FIXME: if a direct callee had indirect callees, it seems like they could
189 // be updated and we would have to reinline even direct calls!
191 if (!CS.getCallSite().getCalledFunction()) {
192 // Loop over all of the actually called functions...
193 ActualCalleesTy::iterator I, E;
194 tie(I, E) = ActualCallees.equal_range(TheCall);
195 unsigned TNum = 0, Num = std::distance(I, E);
196 for (; I != E; ++I, ++TNum) {
197 Function *CalleeFunc = I->second;
198 if (!CalleeFunc->isExternal()) {
199 // Merge the callee's graph into this graph. This works for normal
200 // calls or for self recursion within an SCC.
201 DSGraph &GI = getOrCreateGraph(*CalleeFunc);
203 G.mergeInGraph(CS, *CalleeFunc, GI, DSGraph::KeepModRefBits |
204 DSGraph::StripAllocaBit | DSGraph::DontCloneCallNodes |
205 DSGraph::DontCloneAuxCallNodes);
206 DEBUG(std::cerr << " Inlining graph [" << i << "/" << e-1
207 << ":" << TNum << "/" << Num-1 << "] for "
208 << CalleeFunc->getName() << "["
209 << GI.getGraphSize() << "+" << GI.getAuxFunctionCalls().size()
210 << "] into '" /*<< G.getFunctionNames()*/ << "' ["
211 << G.getGraphSize() << "+" << G.getAuxFunctionCalls().size()
218 // Recompute the Incomplete markers
219 assert(G.getInlinedGlobals().empty());
220 G.maskIncompleteMarkers();
221 G.markIncompleteNodes(DSGraph::MarkFormalArgs);
223 // Delete dead nodes. Treat globals that are unreachable but that can
224 // reach live nodes as live.
225 G.removeDeadNodes(DSGraph::RemoveUnreachableGlobals);