1 //===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
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 file implements the CallGraphSCCPass class, which is used for passes
11 // which are implemented as bottom-up traversals on the call graph. Because
12 // there may be cycles in the call graph, passes of this type operate on the
13 // call-graph in SCC order: that is, they process function bottom-up, except for
14 // recursive functions, which they process all at once.
16 //===----------------------------------------------------------------------===//
18 #include "llvm/CallGraphSCCPass.h"
19 #include "llvm/Analysis/CallGraph.h"
20 #include "llvm/ADT/SCCIterator.h"
21 #include "llvm/PassManagers.h"
22 #include "llvm/Function.h"
25 //===----------------------------------------------------------------------===//
28 /// CGPassManager manages FPPassManagers and CalLGraphSCCPasses.
30 class CGPassManager : public ModulePass, public PMDataManager {
33 CGPassManager(int Depth) : PMDataManager(Depth) { }
35 /// run - Execute all of the passes scheduled for execution. Keep track of
36 /// whether any of the passes modifies the module, and if so, return true.
37 bool runOnModule(Module &M);
39 bool doInitialization(CallGraph &CG);
40 bool doFinalization(CallGraph &CG);
42 /// Pass Manager itself does not invalidate any analysis info.
43 void getAnalysisUsage(AnalysisUsage &Info) const {
44 // CGPassManager walks SCC and it needs CallGraph.
45 Info.addRequired<CallGraph>();
46 Info.setPreservesAll();
49 virtual const char *getPassName() const {
50 return "CallGraph Pass Manager";
53 // Print passes managed by this manager
54 void dumpPassStructure(unsigned Offset) {
55 llvm::cerr << std::string(Offset*2, ' ') << "Call Graph SCC Pass Manager\n";
56 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
57 Pass *P = getContainedPass(Index);
58 P->dumpPassStructure(Offset + 1);
59 dumpLastUses(P, Offset+1);
63 Pass *getContainedPass(unsigned N) {
64 assert ( N < PassVector.size() && "Pass number out of range!");
65 Pass *FP = static_cast<Pass *>(PassVector[N]);
69 virtual PassManagerType getPassManagerType() {
70 return PMT_CallGraphPassManager;
74 /// run - Execute all of the passes scheduled for execution. Keep track of
75 /// whether any of the passes modifies the module, and if so, return true.
76 bool CGPassManager::runOnModule(Module &M) {
77 CallGraph &CG = getAnalysis<CallGraph>();
78 bool Changed = doInitialization(CG);
80 std::string Msg1 = "Executing Pass '";
81 std::string Msg3 = "' Made Modification '";
84 for (scc_iterator<CallGraph*> I = scc_begin(&CG), E = scc_end(&CG);
87 // Run all passes on current SCC
88 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
90 Pass *P = getContainedPass(Index);
91 AnalysisUsage AnUsage;
92 P->getAnalysisUsage(AnUsage);
94 std::string Msg2 = "' on Call Graph ...\n'";
95 dumpPassInfo(P, Msg1, Msg2);
96 dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
98 initializeAnalysisImpl(P);
101 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
102 Changed |= CGSP->runOnSCC(*I); // TODO : What if CG is changed ?
104 FPPassManager *FPP = dynamic_cast<FPPassManager *>(P);
105 assert (FPP && "Invalid CGPassManager member");
107 // Run pass P on all functions current SCC
108 std::vector<CallGraphNode*> &SCC = *I;
109 for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
110 Function *F = SCC[i]->getFunction();
112 std::string Msg4 = "' on Function '" + F->getName() + "'...\n";
113 dumpPassInfo(P, Msg1, Msg4);
114 Changed |= FPP->runOnFunction(*F);
121 dumpPassInfo(P, Msg3, Msg2);
122 dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
124 removeNotPreservedAnalysis(P);
125 recordAvailableAnalysis(P);
126 removeDeadPasses(P, Msg2);
129 Changed |= doFinalization(CG);
134 bool CGPassManager::doInitialization(CallGraph &CG) {
135 bool Changed = false;
136 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
137 Pass *P = getContainedPass(Index);
138 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
139 Changed |= CGSP->doInitialization(CG);
145 bool CGPassManager::doFinalization(CallGraph &CG) {
146 bool Changed = false;
147 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
148 Pass *P = getContainedPass(Index);
149 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
150 Changed |= CGSP->doFinalization(CG);
155 /// Assign pass manager to manage this pass.
156 void CallGraphSCCPass::assignPassManager(PMStack &PMS,
157 PassManagerType PreferredType) {
158 // Find CGPassManager
159 while (!PMS.empty()) {
160 if (PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
166 CGPassManager *CGP = dynamic_cast<CGPassManager *>(PMS.top());
168 // Create new Call Graph SCC Pass Manager if it does not exist.
171 assert (!PMS.empty() && "Unable to create Call Graph Pass Manager");
172 PMDataManager *PMD = PMS.top();
174 // [1] Create new Call Graph Pass Manager
175 CGP = new CGPassManager(PMD->getDepth() + 1);
177 // [2] Set up new manager's top level manager
178 PMTopLevelManager *TPM = PMD->getTopLevelManager();
179 TPM->addIndirectPassManager(CGP);
181 // [3] Assign manager to manage this new manager. This may create
182 // and push new managers into PMS
183 Pass *P = dynamic_cast<Pass *>(CGP);
184 P->assignPassManager(PMS);
186 // [4] Push new manager into PMS
193 /// getAnalysisUsage - For this class, we declare that we require and preserve
194 /// the call graph. If the derived class implements this method, it should
195 /// always explicitly call the implementation here.
196 void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
197 AU.addRequired<CallGraph>();
198 AU.addPreserved<CallGraph>();