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"
24 //===----------------------------------------------------------------------===//
27 /// CGPassManager manages FPPassManagers and CalLGraphSCCPasses.
29 class CGPassManager : public ModulePass, public PMDataManager {
32 CGPassManager(int Depth) : PMDataManager(Depth) { }
34 /// run - Execute all of the passes scheduled for execution. Keep track of
35 /// whether any of the passes modifies the module, and if so, return true.
36 bool runOnModule(Module &M);
38 bool doInitialization(CallGraph &CG);
39 bool doFinalization(CallGraph &CG);
41 /// Pass Manager itself does not invalidate any analysis info.
42 void getAnalysisUsage(AnalysisUsage &Info) const {
43 // CGPassManager walks SCC and it needs CallGraph.
44 Info.addRequired<CallGraph>();
45 Info.setPreservesAll();
48 virtual const char *getPassName() const {
49 return "CallGraph Pass Manager";
52 // Print passes managed by this manager
53 void dumpPassStructure(unsigned Offset) {
54 llvm::cerr << std::string(Offset*2, ' ') << "Call Graph SCC Pass Manager\n";
55 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
56 Pass *P = getContainedPass(Index);
57 P->dumpPassStructure(Offset + 1);
58 dumpLastUses(P, Offset+1);
62 Pass *getContainedPass(unsigned N) {
63 assert ( N < PassVector.size() && "Pass number out of range!");
64 Pass *FP = static_cast<Pass *>(PassVector[N]);
68 virtual PassManagerType getPassManagerType() {
69 return PMT_CallGraphPassManager;
73 /// run - Execute all of the passes scheduled for execution. Keep track of
74 /// whether any of the passes modifies the module, and if so, return true.
75 bool CGPassManager::runOnModule(Module &M) {
76 CallGraph &CG = getAnalysis<CallGraph>();
77 bool Changed = doInitialization(CG);
79 std::string Msg1 = "Executing Pass '";
80 std::string Msg3 = "' Made Modification '";
83 for (scc_iterator<CallGraph*> I = scc_begin(&CG), E = scc_end(&CG);
86 // Run all passes on current SCC
87 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
89 Pass *P = getContainedPass(Index);
90 AnalysisUsage AnUsage;
91 P->getAnalysisUsage(AnUsage);
93 std::string Msg2 = "' on Call Graph ...\n'";
94 dumpPassInfo(P, Msg1, Msg2);
95 dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
97 initializeAnalysisImpl(P);
100 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
101 Changed |= CGSP->runOnSCC(*I); // TODO : What if CG is changed ?
103 FPPassManager *FPP = dynamic_cast<FPPassManager *>(P);
104 assert (FPP && "Invalid CGPassManager member");
106 // Run pass P on all functions current SCC
107 std::vector<CallGraphNode*> &SCC = *I;
108 for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
109 Function *F = SCC[i]->getFunction();
111 Changed |= FPP->runOnFunction(*F);
117 dumpPassInfo(P, Msg3, Msg2);
118 dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
120 removeNotPreservedAnalysis(P);
121 recordAvailableAnalysis(P);
122 removeDeadPasses(P, Msg2);
125 Changed |= doFinalization(CG);
130 bool CGPassManager::doInitialization(CallGraph &CG) {
131 bool Changed = false;
132 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
133 Pass *P = getContainedPass(Index);
134 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
135 Changed |= CGSP->doInitialization(CG);
141 bool CGPassManager::doFinalization(CallGraph &CG) {
142 bool Changed = false;
143 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
144 Pass *P = getContainedPass(Index);
145 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
146 Changed |= CGSP->doFinalization(CG);
151 /// Assign pass manager to manage this pass.
152 void CallGraphSCCPass::assignPassManager(PMStack &PMS,
153 PassManagerType PreferredType) {
154 // Find CGPassManager
155 while (!PMS.empty()) {
156 if (PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
162 CGPassManager *CGP = dynamic_cast<CGPassManager *>(PMS.top());
164 // Create new Call Graph SCC Pass Manager if it does not exist.
167 assert (!PMS.empty() && "Unable to create Call Graph Pass Manager");
168 PMDataManager *PMD = PMS.top();
170 // [1] Create new Call Graph Pass Manager
171 CGP = new CGPassManager(PMD->getDepth() + 1);
173 // [2] Set up new manager's top level manager
174 PMTopLevelManager *TPM = PMD->getTopLevelManager();
175 TPM->addIndirectPassManager(CGP);
177 // [3] Assign manager to manage this new manager. This may create
178 // and push new managers into PMS
179 Pass *P = dynamic_cast<Pass *>(CGP);
180 P->assignPassManager(PMS);
182 // [4] Push new manager into PMS
189 /// getAnalysisUsage - For this class, we declare that we require and preserve
190 /// the call graph. If the derived class implements this method, it should
191 /// always explicitly call the implementation here.
192 void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
193 AU.addRequired<CallGraph>();
194 AU.addPreserved<CallGraph>();