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/SCCIterator.h"
20 #include "Support/STLExtras.h"
24 RegisterAnalysis<CompleteBUDataStructures>
25 X("cbudatastructure", "'Complete' Bottom-up Data Structure Analysis");
29 // run - Calculate the bottom up data structure graphs for each function in the
32 bool CompleteBUDataStructures::run(Module &M) {
33 BUDataStructures &BU = getAnalysis<BUDataStructures>();
34 GlobalsGraph = new DSGraph(BU.getGlobalsGraph());
35 GlobalsGraph->setPrintAuxCalls();
37 // Our call graph is the same as the BU data structures call graph
38 ActualCallees = BU.getActualCallees();
40 #if 1 // REMOVE ME EVENTUALLY
41 // FIXME: TEMPORARY (remove once finalization of indirect call sites in the
42 // globals graph has been implemented in the BU pass)
43 TDDataStructures &TD = getAnalysis<TDDataStructures>();
45 // The call graph extractable from the TD pass is _much more complete_ and
46 // trustable than that generated by the BU pass so far. Until this is fixed,
47 // we hack it like this:
48 for (Module::iterator MI = M.begin(), ME = M.end(); MI != ME; ++MI) {
49 if (MI->isExternal()) continue;
50 const std::vector<DSCallSite> &CSs = TD.getDSGraph(*MI).getFunctionCalls();
52 for (unsigned CSi = 0, e = CSs.size(); CSi != e; ++CSi) {
53 if (CSs[CSi].isIndirectCall()) {
54 Instruction *TheCall = CSs[CSi].getCallSite().getInstruction();
56 const std::vector<GlobalValue*> &Callees =
57 CSs[CSi].getCalleeNode()->getGlobals();
58 for (unsigned i = 0, e = Callees.size(); i != e; ++i)
59 if (Function *F = dyn_cast<Function>(Callees[i]))
60 ActualCallees.insert(std::make_pair(TheCall, F));
66 std::vector<DSGraph*> Stack;
67 hash_map<DSGraph*, unsigned> ValMap;
70 if (Function *Main = M.getMainFunction()) {
71 calculateSCCGraphs(getOrCreateGraph(*Main), Stack, NextID, ValMap);
73 std::cerr << "CBU-DSA: No 'main' function found!\n";
76 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
77 if (!I->isExternal() && !DSInfo.count(I))
78 calculateSCCGraphs(getOrCreateGraph(*I), Stack, NextID, ValMap);
80 GlobalsGraph->removeTriviallyDeadNodes();
84 DSGraph &CompleteBUDataStructures::getOrCreateGraph(Function &F) {
85 // Has the graph already been created?
86 DSGraph *&Graph = DSInfo[&F];
87 if (Graph) return *Graph;
89 // Copy the BU graph...
90 Graph = new DSGraph(getAnalysis<BUDataStructures>().getDSGraph(F));
91 Graph->setGlobalsGraph(GlobalsGraph);
92 Graph->setPrintAuxCalls();
94 // Make sure to update the DSInfo map for all of the functions currently in
96 for (DSGraph::ReturnNodesTy::iterator I = Graph->getReturnNodes().begin();
97 I != Graph->getReturnNodes().end(); ++I)
98 DSInfo[I->first] = Graph;
105 unsigned CompleteBUDataStructures::calculateSCCGraphs(DSGraph &FG,
106 std::vector<DSGraph*> &Stack,
108 hash_map<DSGraph*, unsigned> &ValMap) {
109 assert(!ValMap.count(&FG) && "Shouldn't revisit functions!");
110 unsigned Min = NextID++, MyID = Min;
112 Stack.push_back(&FG);
114 // The edges out of the current node are the call site targets...
115 for (unsigned i = 0, e = FG.getFunctionCalls().size(); i != e; ++i) {
116 Instruction *Call = FG.getFunctionCalls()[i].getCallSite().getInstruction();
118 // Loop over all of the actually called functions...
119 ActualCalleesTy::iterator I, E;
120 for (tie(I, E) = ActualCallees.equal_range(Call); I != E; ++I)
121 if (!I->second->isExternal()) {
122 DSGraph &Callee = getOrCreateGraph(*I->second);
124 // Have we visited the destination function yet?
125 hash_map<DSGraph*, unsigned>::iterator It = ValMap.find(&Callee);
126 if (It == ValMap.end()) // No, visit it now.
127 M = calculateSCCGraphs(Callee, Stack, NextID, ValMap);
128 else // Yes, get it's number.
130 if (M < Min) Min = M;
134 assert(ValMap[&FG] == MyID && "SCC construction assumption wrong!");
136 return Min; // This is part of a larger SCC!
138 // If this is a new SCC, process it now.
139 bool IsMultiNodeSCC = false;
140 while (Stack.back() != &FG) {
141 DSGraph *NG = Stack.back();
144 DSGraph::NodeMapTy NodeMap;
145 FG.cloneInto(*NG, FG.getScalarMap(), FG.getReturnNodes(), NodeMap);
147 // Update the DSInfo map and delete the old graph...
148 for (DSGraph::ReturnNodesTy::iterator I = NG->getReturnNodes().begin();
149 I != NG->getReturnNodes().end(); ++I)
150 DSInfo[I->first] = &FG;
154 IsMultiNodeSCC = true;
157 // Clean up the graph before we start inlining a bunch again...
159 FG.removeTriviallyDeadNodes();
168 /// processGraph - Process the BU graphs for the program in bottom-up order on
169 /// the SCC of the __ACTUAL__ call graph. This builds "complete" BU graphs.
170 void CompleteBUDataStructures::processGraph(DSGraph &G) {
172 // The edges out of the current node are the call site targets...
173 for (unsigned i = 0, e = G.getFunctionCalls().size(); i != e; ++i) {
174 const DSCallSite &CS = G.getFunctionCalls()[i];
175 Instruction *TheCall = CS.getCallSite().getInstruction();
177 // The Normal BU pass will have taken care of direct calls well already,
178 // don't worry about them.
179 if (!CS.getCallSite().getCalledFunction()) {
180 // Loop over all of the actually called functions...
181 ActualCalleesTy::iterator I, E;
182 for (tie(I, E) = ActualCallees.equal_range(TheCall); I != E; ++I) {
183 Function *CalleeFunc = I->second;
184 if (!CalleeFunc->isExternal()) {
185 // Merge the callee's graph into this graph. This works for normal
186 // calls or for self recursion within an SCC.
187 G.mergeInGraph(CS, *CalleeFunc, getOrCreateGraph(*CalleeFunc),
188 DSGraph::KeepModRefBits |
189 DSGraph::StripAllocaBit |
190 DSGraph::DontCloneCallNodes);
196 // Recompute the Incomplete markers
197 assert(G.getInlinedGlobals().empty());
198 G.maskIncompleteMarkers();
199 G.markIncompleteNodes(DSGraph::MarkFormalArgs);
201 // Delete dead nodes. Treat globals that are unreachable but that can
202 // reach live nodes as live.
203 G.removeDeadNodes(DSGraph::KeepUnreachableGlobals);