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() const {
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);
81 for (scc_iterator<CallGraph*> I = scc_begin(&CG), E = scc_end(&CG);
84 // Run all passes on current SCC
85 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
87 Pass *P = getContainedPass(Index);
88 AnalysisUsage AnUsage;
89 P->getAnalysisUsage(AnUsage);
91 dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, "");
92 dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
94 initializeAnalysisImpl(P);
97 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
98 Changed |= CGSP->runOnSCC(*I); // TODO : What if CG is changed ?
100 FPPassManager *FPP = dynamic_cast<FPPassManager *>(P);
101 assert (FPP && "Invalid CGPassManager member");
103 // Run pass P on all functions current SCC
104 std::vector<CallGraphNode*> &SCC = *I;
105 for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
106 Function *F = SCC[i]->getFunction();
108 dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
109 Changed |= FPP->runOnFunction(*F);
116 dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
117 dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
119 removeNotPreservedAnalysis(P);
120 recordAvailableAnalysis(P);
121 removeDeadPasses(P, "", ON_CG_MSG);
124 Changed |= doFinalization(CG);
129 bool CGPassManager::doInitialization(CallGraph &CG) {
130 bool Changed = false;
131 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
132 Pass *P = getContainedPass(Index);
133 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
134 Changed |= CGSP->doInitialization(CG);
140 bool CGPassManager::doFinalization(CallGraph &CG) {
141 bool Changed = false;
142 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
143 Pass *P = getContainedPass(Index);
144 if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
145 Changed |= CGSP->doFinalization(CG);
150 /// Assign pass manager to manage this pass.
151 void CallGraphSCCPass::assignPassManager(PMStack &PMS,
152 PassManagerType PreferredType) {
153 // Find CGPassManager
154 while (!PMS.empty()) {
155 if (PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
161 CGPassManager *CGP = dynamic_cast<CGPassManager *>(PMS.top());
163 // Create new Call Graph SCC Pass Manager if it does not exist.
166 assert (!PMS.empty() && "Unable to create Call Graph Pass Manager");
167 PMDataManager *PMD = PMS.top();
169 // [1] Create new Call Graph Pass Manager
170 CGP = new CGPassManager(PMD->getDepth() + 1);
172 // [2] Set up new manager's top level manager
173 PMTopLevelManager *TPM = PMD->getTopLevelManager();
174 TPM->addIndirectPassManager(CGP);
176 // [3] Assign manager to manage this new manager. This may create
177 // and push new managers into PMS
178 Pass *P = dynamic_cast<Pass *>(CGP);
179 P->assignPassManager(PMS);
181 // [4] Push new manager into PMS
188 /// getAnalysisUsage - For this class, we declare that we require and preserve
189 /// the call graph. If the derived class implements this method, it should
190 /// always explicitly call the implementation here.
191 void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
192 AU.addRequired<CallGraph>();
193 AU.addPreserved<CallGraph>();