1 //===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // 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.
32 class CGPassManager : public ModulePass, public PMDataManager {
36 explicit CGPassManager(int Depth)
37 : ModulePass((intptr_t)&ID), PMDataManager(Depth) { }
39 /// run - Execute all of the passes scheduled for execution. Keep track of
40 /// whether any of the passes modifies the module, and if so, return true.
41 bool runOnModule(Module &M);
43 bool doInitialization(CallGraph &CG);
44 bool doFinalization(CallGraph &CG);
46 /// Pass Manager itself does not invalidate any analysis info.
47 void getAnalysisUsage(AnalysisUsage &Info) const {
48 // CGPassManager walks SCC and it needs CallGraph.
49 Info.addRequired<CallGraph>();
50 Info.setPreservesAll();
53 virtual const char *getPassName() const {
54 return "CallGraph Pass Manager";
57 // Print passes managed by this manager
58 void dumpPassStructure(unsigned Offset) {
59 llvm::cerr << std::string(Offset*2, ' ') << "Call Graph SCC Pass Manager\n";
60 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
61 Pass *P = getContainedPass(Index);
62 P->dumpPassStructure(Offset + 1);
63 dumpLastUses(P, Offset+1);
67 Pass *getContainedPass(unsigned N) {
68 assert ( N < PassVector.size() && "Pass number out of range!");
69 Pass *FP = static_cast<Pass *>(PassVector[N]);
73 virtual PassManagerType getPassManagerType() const {
74 return PMT_CallGraphPassManager;
80 char CGPassManager::ID = 0;
81 /// run - Execute all of the passes scheduled for execution. Keep track of
82 /// whether any of the passes modifies the module, and if so, return true.
83 bool CGPassManager::runOnModule(Module &M) {
84 CallGraph &CG = getAnalysis<CallGraph>();
85 bool Changed = doInitialization(CG);
88 for (scc_iterator<CallGraph*> I = scc_begin(&CG), E = scc_end(&CG);
91 // Run all passes on current SCC
92 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
93 Pass *P = getContainedPass(Index);
94 AnalysisUsage AnUsage;
95 P->getAnalysisUsage(AnUsage);
97 dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, "");
98 dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
100 initializeAnalysisImpl(P);
103 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
104 Changed |= CGSP->runOnSCC(*I); // TODO : What if CG is changed ?
106 FPPassManager *FPP = dynamic_cast<FPPassManager *>(P);
107 assert (FPP && "Invalid CGPassManager member");
109 // Run pass P on all functions current SCC
110 std::vector<CallGraphNode*> &SCC = *I;
111 for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
112 Function *F = SCC[i]->getFunction();
114 dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getNameStart());
115 Changed |= FPP->runOnFunction(*F);
122 dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
123 dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
125 verifyPreservedAnalysis(P);
126 removeNotPreservedAnalysis(P);
127 recordAvailableAnalysis(P);
128 removeDeadPasses(P, "", ON_CG_MSG);
131 Changed |= doFinalization(CG);
136 bool CGPassManager::doInitialization(CallGraph &CG) {
137 bool Changed = false;
138 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
139 Pass *P = getContainedPass(Index);
140 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
141 Changed |= CGSP->doInitialization(CG);
147 bool CGPassManager::doFinalization(CallGraph &CG) {
148 bool Changed = false;
149 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
150 Pass *P = getContainedPass(Index);
151 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
152 Changed |= CGSP->doFinalization(CG);
157 /// Assign pass manager to manage this pass.
158 void CallGraphSCCPass::assignPassManager(PMStack &PMS,
159 PassManagerType PreferredType) {
160 // Find CGPassManager
161 while (!PMS.empty() &&
162 PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
165 assert (!PMS.empty() && "Unable to handle Call Graph Pass");
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 TPM->schedulePass(P);
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>();