1//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 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. 15// 16//===----------------------------------------------------------------------===// 17 18#include "llvm/Analysis/CallGraphSCCPass.h" 19#include "llvm/ADT/SCCIterator.h" 20#include "llvm/ADT/Statistic.h" 21#include "llvm/Analysis/CallGraph.h" 22#include "llvm/IR/Function.h" 23#include "llvm/IR/IntrinsicInst.h" 24#include "llvm/IR/LLVMContext.h" 25#include "llvm/IR/LegacyPassManagers.h" 26#include "llvm/Support/CommandLine.h" 27#include "llvm/Support/Debug.h" 28#include "llvm/Support/Timer.h" 29#include "llvm/Support/raw_ostream.h" 30using namespace llvm; 31 32#define DEBUG_TYPE "cgscc-passmgr" 33 34static cl::opt<unsigned> 35MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4)); 36 37STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC"); 38 39//===----------------------------------------------------------------------===// 40// CGPassManager 41// 42/// CGPassManager manages FPPassManagers and CallGraphSCCPasses. 43 44namespace { 45 46class CGPassManager : public ModulePass, public PMDataManager { 47public: 48 static char ID; 49 explicit CGPassManager() 50 : ModulePass(ID), PMDataManager() { } 51 52 /// Execute all of the passes scheduled for execution. Keep track of 53 /// whether any of the passes modifies the module, and if so, return true. 54 bool runOnModule(Module &M) override; 55 56 using ModulePass::doInitialization; 57 using ModulePass::doFinalization; 58 59 bool doInitialization(CallGraph &CG); 60 bool doFinalization(CallGraph &CG); 61 62 /// Pass Manager itself does not invalidate any analysis info. 63 void getAnalysisUsage(AnalysisUsage &Info) const override { 64 // CGPassManager walks SCC and it needs CallGraph. 65 Info.addRequired<CallGraphWrapperPass>(); 66 Info.setPreservesAll(); 67 } 68 69 const char *getPassName() const override { 70 return "CallGraph Pass Manager"; 71 } 72 73 PMDataManager *getAsPMDataManager() override { return this; } 74 Pass *getAsPass() override { return this; } 75 76 // Print passes managed by this manager 77 void dumpPassStructure(unsigned Offset) override { 78 errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n"; 79 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 80 Pass *P = getContainedPass(Index); 81 P->dumpPassStructure(Offset + 1); 82 dumpLastUses(P, Offset+1); 83 } 84 } 85 86 Pass *getContainedPass(unsigned N) { 87 assert(N < PassVector.size() && "Pass number out of range!"); 88 return static_cast<Pass *>(PassVector[N]); 89 } 90 91 PassManagerType getPassManagerType() const override { 92 return PMT_CallGraphPassManager; 93 } 94 95private: 96 bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG, 97 bool &DevirtualizedCall); 98 99 bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC, 100 CallGraph &CG, bool &CallGraphUpToDate, 101 bool &DevirtualizedCall); 102 bool RefreshCallGraph(CallGraphSCC &CurSCC, CallGraph &CG, 103 bool IsCheckingMode); 104}; 105 106} // end anonymous namespace. 107 108char CGPassManager::ID = 0; 109 110 111bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC, 112 CallGraph &CG, bool &CallGraphUpToDate, 113 bool &DevirtualizedCall) { 114 bool Changed = false; 115 PMDataManager *PM = P->getAsPMDataManager(); 116 117 if (!PM) { 118 CallGraphSCCPass *CGSP = (CallGraphSCCPass*)P; 119 if (!CallGraphUpToDate) { 120 DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false); 121 CallGraphUpToDate = true; 122 } 123 124 { 125 TimeRegion PassTimer(getPassTimer(CGSP)); 126 Changed = CGSP->runOnSCC(CurSCC); 127 } 128 129 // After the CGSCCPass is done, when assertions are enabled, use 130 // RefreshCallGraph to verify that the callgraph was correctly updated. 131#ifndef NDEBUG 132 if (Changed) 133 RefreshCallGraph(CurSCC, CG, true); 134#endif 135 136 return Changed; 137 } 138 139 140 assert(PM->getPassManagerType() == PMT_FunctionPassManager && 141 "Invalid CGPassManager member"); 142 FPPassManager *FPP = (FPPassManager*)P; 143 144 // Run pass P on all functions in the current SCC. 145 for (CallGraphNode *CGN : CurSCC) { 146 if (Function *F = CGN->getFunction()) { 147 dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName()); 148 { 149 TimeRegion PassTimer(getPassTimer(FPP)); 150 Changed |= FPP->runOnFunction(*F); 151 } 152 F->getContext().yield(); 153 } 154 } 155 156 // The function pass(es) modified the IR, they may have clobbered the 157 // callgraph. 158 if (Changed && CallGraphUpToDate) { 159 DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: " 160 << P->getPassName() << '\n'); 161 CallGraphUpToDate = false; 162 } 163 return Changed; 164} 165 166 167/// Scan the functions in the specified CFG and resync the 168/// callgraph with the call sites found in it. This is used after 169/// FunctionPasses have potentially munged the callgraph, and can be used after 170/// CallGraphSCC passes to verify that they correctly updated the callgraph. 171/// 172/// This function returns true if it devirtualized an existing function call, 173/// meaning it turned an indirect call into a direct call. This happens when 174/// a function pass like GVN optimizes away stuff feeding the indirect call. 175/// This never happens in checking mode. 176/// 177bool CGPassManager::RefreshCallGraph(CallGraphSCC &CurSCC, 178 CallGraph &CG, bool CheckingMode) { 179 DenseMap<Value*, CallGraphNode*> CallSites; 180 181 DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size() 182 << " nodes:\n"; 183 for (CallGraphNode *CGN : CurSCC) 184 CGN->dump(); 185 ); 186 187 bool MadeChange = false; 188 bool DevirtualizedCall = false; 189 190 // Scan all functions in the SCC. 191 unsigned FunctionNo = 0; 192 for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end(); 193 SCCIdx != E; ++SCCIdx, ++FunctionNo) { 194 CallGraphNode *CGN = *SCCIdx; 195 Function *F = CGN->getFunction(); 196 if (!F || F->isDeclaration()) continue; 197 198 // Walk the function body looking for call sites. Sync up the call sites in 199 // CGN with those actually in the function. 200 201 // Keep track of the number of direct and indirect calls that were 202 // invalidated and removed. 203 unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0; 204 205 // Get the set of call sites currently in the function. 206 for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ) { 207 // If this call site is null, then the function pass deleted the call 208 // entirely and the WeakVH nulled it out. 209 if (!I->first || 210 // If we've already seen this call site, then the FunctionPass RAUW'd 211 // one call with another, which resulted in two "uses" in the edge 212 // list of the same call. 213 CallSites.count(I->first) || 214 215 // If the call edge is not from a call or invoke, or it is a 216 // instrinsic call, then the function pass RAUW'd a call with 217 // another value. This can happen when constant folding happens 218 // of well known functions etc. 219 !CallSite(I->first) || 220 (CallSite(I->first).getCalledFunction() && 221 CallSite(I->first).getCalledFunction()->isIntrinsic() && 222 Intrinsic::isLeaf( 223 CallSite(I->first).getCalledFunction()->getIntrinsicID()))) { 224 assert(!CheckingMode && 225 "CallGraphSCCPass did not update the CallGraph correctly!"); 226 227 // If this was an indirect call site, count it. 228 if (!I->second->getFunction()) 229 ++NumIndirectRemoved; 230 else 231 ++NumDirectRemoved; 232 233 // Just remove the edge from the set of callees, keep track of whether 234 // I points to the last element of the vector. 235 bool WasLast = I + 1 == E; 236 CGN->removeCallEdge(I); 237 238 // If I pointed to the last element of the vector, we have to bail out: 239 // iterator checking rejects comparisons of the resultant pointer with 240 // end. 241 if (WasLast) 242 break; 243 E = CGN->end(); 244 continue; 245 } 246 247 assert(!CallSites.count(I->first) && 248 "Call site occurs in node multiple times"); 249 250 CallSite CS(I->first); 251 if (CS) { 252 Function *Callee = CS.getCalledFunction(); 253 // Ignore intrinsics because they're not really function calls. 254 if (!Callee || !(Callee->isIntrinsic())) 255 CallSites.insert(std::make_pair(I->first, I->second)); 256 } 257 ++I; 258 } 259 260 // Loop over all of the instructions in the function, getting the callsites. 261 // Keep track of the number of direct/indirect calls added. 262 unsigned NumDirectAdded = 0, NumIndirectAdded = 0; 263 264 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 265 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { 266 CallSite CS(cast<Value>(I)); 267 if (!CS) continue; 268 Function *Callee = CS.getCalledFunction(); 269 if (Callee && Callee->isIntrinsic()) continue; 270 271 // If this call site already existed in the callgraph, just verify it 272 // matches up to expectations and remove it from CallSites. 273 DenseMap<Value*, CallGraphNode*>::iterator ExistingIt = 274 CallSites.find(CS.getInstruction()); 275 if (ExistingIt != CallSites.end()) { 276 CallGraphNode *ExistingNode = ExistingIt->second; 277 278 // Remove from CallSites since we have now seen it. 279 CallSites.erase(ExistingIt); 280 281 // Verify that the callee is right. 282 if (ExistingNode->getFunction() == CS.getCalledFunction()) 283 continue; 284 285 // If we are in checking mode, we are not allowed to actually mutate 286 // the callgraph. If this is a case where we can infer that the 287 // callgraph is less precise than it could be (e.g. an indirect call 288 // site could be turned direct), don't reject it in checking mode, and 289 // don't tweak it to be more precise. 290 if (CheckingMode && CS.getCalledFunction() && 291 ExistingNode->getFunction() == nullptr) 292 continue; 293 294 assert(!CheckingMode && 295 "CallGraphSCCPass did not update the CallGraph correctly!"); 296 297 // If not, we either went from a direct call to indirect, indirect to 298 // direct, or direct to different direct. 299 CallGraphNode *CalleeNode; 300 if (Function *Callee = CS.getCalledFunction()) { 301 CalleeNode = CG.getOrInsertFunction(Callee); 302 // Keep track of whether we turned an indirect call into a direct 303 // one. 304 if (!ExistingNode->getFunction()) { 305 DevirtualizedCall = true; 306 DEBUG(dbgs() << " CGSCCPASSMGR: Devirtualized call to '" 307 << Callee->getName() << "'\n"); 308 } 309 } else { 310 CalleeNode = CG.getCallsExternalNode(); 311 } 312 313 // Update the edge target in CGN. 314 CGN->replaceCallEdge(CS, CS, CalleeNode); 315 MadeChange = true; 316 continue; 317 } 318 319 assert(!CheckingMode && 320 "CallGraphSCCPass did not update the CallGraph correctly!"); 321 322 // If the call site didn't exist in the CGN yet, add it. 323 CallGraphNode *CalleeNode; 324 if (Function *Callee = CS.getCalledFunction()) { 325 CalleeNode = CG.getOrInsertFunction(Callee); 326 ++NumDirectAdded; 327 } else { 328 CalleeNode = CG.getCallsExternalNode(); 329 ++NumIndirectAdded; 330 } 331 332 CGN->addCalledFunction(CS, CalleeNode); 333 MadeChange = true; 334 } 335 336 // We scanned the old callgraph node, removing invalidated call sites and 337 // then added back newly found call sites. One thing that can happen is 338 // that an old indirect call site was deleted and replaced with a new direct 339 // call. In this case, we have devirtualized a call, and CGSCCPM would like 340 // to iteratively optimize the new code. Unfortunately, we don't really 341 // have a great way to detect when this happens. As an approximation, we 342 // just look at whether the number of indirect calls is reduced and the 343 // number of direct calls is increased. There are tons of ways to fool this 344 // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a 345 // direct call) but this is close enough. 346 if (NumIndirectRemoved > NumIndirectAdded && 347 NumDirectRemoved < NumDirectAdded) 348 DevirtualizedCall = true; 349 350 // After scanning this function, if we still have entries in callsites, then 351 // they are dangling pointers. WeakVH should save us for this, so abort if 352 // this happens. 353 assert(CallSites.empty() && "Dangling pointers found in call sites map"); 354 355 // Periodically do an explicit clear to remove tombstones when processing 356 // large scc's. 357 if ((FunctionNo & 15) == 15) 358 CallSites.clear(); 359 } 360 361 DEBUG(if (MadeChange) { 362 dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n"; 363 for (CallGraphNode *CGN : CurSCC) 364 CGN->dump(); 365 if (DevirtualizedCall) 366 dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n"; 367 368 } else { 369 dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n"; 370 } 371 ); 372 (void)MadeChange; 373 374 return DevirtualizedCall; 375} 376 377/// Execute the body of the entire pass manager on the specified SCC. 378/// This keeps track of whether a function pass devirtualizes 379/// any calls and returns it in DevirtualizedCall. 380bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG, 381 bool &DevirtualizedCall) { 382 bool Changed = false; 383 384 // Keep track of whether the callgraph is known to be up-to-date or not. 385 // The CGSSC pass manager runs two types of passes: 386 // CallGraphSCC Passes and other random function passes. Because other 387 // random function passes are not CallGraph aware, they may clobber the 388 // call graph by introducing new calls or deleting other ones. This flag 389 // is set to false when we run a function pass so that we know to clean up 390 // the callgraph when we need to run a CGSCCPass again. 391 bool CallGraphUpToDate = true; 392 393 // Run all passes on current SCC. 394 for (unsigned PassNo = 0, e = getNumContainedPasses(); 395 PassNo != e; ++PassNo) { 396 Pass *P = getContainedPass(PassNo); 397 398 // If we're in -debug-pass=Executions mode, construct the SCC node list, 399 // otherwise avoid constructing this string as it is expensive. 400 if (isPassDebuggingExecutionsOrMore()) { 401 std::string Functions; 402 #ifndef NDEBUG 403 raw_string_ostream OS(Functions); 404 for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end(); 405 I != E; ++I) { 406 if (I != CurSCC.begin()) OS << ", "; 407 (*I)->print(OS); 408 } 409 OS.flush(); 410 #endif 411 dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions); 412 } 413 dumpRequiredSet(P); 414 415 initializeAnalysisImpl(P); 416 417 // Actually run this pass on the current SCC. 418 Changed |= RunPassOnSCC(P, CurSCC, CG, 419 CallGraphUpToDate, DevirtualizedCall); 420 421 if (Changed) 422 dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, ""); 423 dumpPreservedSet(P); 424 425 verifyPreservedAnalysis(P); 426 removeNotPreservedAnalysis(P); 427 recordAvailableAnalysis(P); 428 removeDeadPasses(P, "", ON_CG_MSG); 429 } 430 431 // If the callgraph was left out of date (because the last pass run was a 432 // functionpass), refresh it before we move on to the next SCC. 433 if (!CallGraphUpToDate) 434 DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false); 435 return Changed; 436} 437 438/// Execute all of the passes scheduled for execution. Keep track of 439/// whether any of the passes modifies the module, and if so, return true. 440bool CGPassManager::runOnModule(Module &M) { 441 CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph(); 442 bool Changed = doInitialization(CG); 443 444 // Walk the callgraph in bottom-up SCC order. 445 scc_iterator<CallGraph*> CGI = scc_begin(&CG); 446 447 CallGraphSCC CurSCC(&CGI); 448 while (!CGI.isAtEnd()) { 449 // Copy the current SCC and increment past it so that the pass can hack 450 // on the SCC if it wants to without invalidating our iterator. 451 const std::vector<CallGraphNode *> &NodeVec = *CGI; 452 CurSCC.initialize(NodeVec.data(), NodeVec.data() + NodeVec.size()); 453 ++CGI; 454 455 // At the top level, we run all the passes in this pass manager on the 456 // functions in this SCC. However, we support iterative compilation in the 457 // case where a function pass devirtualizes a call to a function. For 458 // example, it is very common for a function pass (often GVN or instcombine) 459 // to eliminate the addressing that feeds into a call. With that improved 460 // information, we would like the call to be an inline candidate, infer 461 // mod-ref information etc. 462 // 463 // Because of this, we allow iteration up to a specified iteration count. 464 // This only happens in the case of a devirtualized call, so we only burn 465 // compile time in the case that we're making progress. We also have a hard 466 // iteration count limit in case there is crazy code. 467 unsigned Iteration = 0; 468 bool DevirtualizedCall = false; 469 do { 470 DEBUG(if (Iteration) 471 dbgs() << " SCCPASSMGR: Re-visiting SCC, iteration #" 472 << Iteration << '\n'); 473 DevirtualizedCall = false; 474 Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall); 475 } while (Iteration++ < MaxIterations && DevirtualizedCall); 476 477 if (DevirtualizedCall) 478 DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after " << Iteration 479 << " times, due to -max-cg-scc-iterations\n"); 480 481 if (Iteration > MaxSCCIterations) 482 MaxSCCIterations = Iteration; 483 484 } 485 Changed |= doFinalization(CG); 486 return Changed; 487} 488 489 490/// Initialize CG 491bool CGPassManager::doInitialization(CallGraph &CG) { 492 bool Changed = false; 493 for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) { 494 if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) { 495 assert(PM->getPassManagerType() == PMT_FunctionPassManager && 496 "Invalid CGPassManager member"); 497 Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule()); 498 } else { 499 Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG); 500 } 501 } 502 return Changed; 503} 504 505/// Finalize CG 506bool CGPassManager::doFinalization(CallGraph &CG) { 507 bool Changed = false; 508 for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) { 509 if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) { 510 assert(PM->getPassManagerType() == PMT_FunctionPassManager && 511 "Invalid CGPassManager member"); 512 Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule()); 513 } else { 514 Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG); 515 } 516 } 517 return Changed; 518} 519 520//===----------------------------------------------------------------------===// 521// CallGraphSCC Implementation 522//===----------------------------------------------------------------------===// 523 524/// This informs the SCC and the pass manager that the specified 525/// Old node has been deleted, and New is to be used in its place. 526void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) { 527 assert(Old != New && "Should not replace node with self"); 528 for (unsigned i = 0; ; ++i) { 529 assert(i != Nodes.size() && "Node not in SCC"); 530 if (Nodes[i] != Old) continue; 531 Nodes[i] = New; 532 break; 533 } 534 535 // Update the active scc_iterator so that it doesn't contain dangling 536 // pointers to the old CallGraphNode. 537 scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context; 538 CGI->ReplaceNode(Old, New); 539} 540 541 542//===----------------------------------------------------------------------===// 543// CallGraphSCCPass Implementation 544//===----------------------------------------------------------------------===// 545 546/// Assign pass manager to manage this pass. 547void CallGraphSCCPass::assignPassManager(PMStack &PMS, 548 PassManagerType PreferredType) { 549 // Find CGPassManager 550 while (!PMS.empty() && 551 PMS.top()->getPassManagerType() > PMT_CallGraphPassManager) 552 PMS.pop(); 553 554 assert(!PMS.empty() && "Unable to handle Call Graph Pass"); 555 CGPassManager *CGP; 556 557 if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager) 558 CGP = (CGPassManager*)PMS.top(); 559 else { 560 // Create new Call Graph SCC Pass Manager if it does not exist. 561 assert(!PMS.empty() && "Unable to create Call Graph Pass Manager"); 562 PMDataManager *PMD = PMS.top(); 563 564 // [1] Create new Call Graph Pass Manager 565 CGP = new CGPassManager(); 566 567 // [2] Set up new manager's top level manager 568 PMTopLevelManager *TPM = PMD->getTopLevelManager(); 569 TPM->addIndirectPassManager(CGP); 570 571 // [3] Assign manager to manage this new manager. This may create 572 // and push new managers into PMS 573 Pass *P = CGP; 574 TPM->schedulePass(P); 575 576 // [4] Push new manager into PMS 577 PMS.push(CGP); 578 } 579 580 CGP->add(this); 581} 582 583/// For this class, we declare that we require and preserve the call graph. 584/// If the derived class implements this method, it should 585/// always explicitly call the implementation here. 586void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const { 587 AU.addRequired<CallGraphWrapperPass>(); 588 AU.addPreserved<CallGraphWrapperPass>(); 589} 590 591 592//===----------------------------------------------------------------------===// 593// PrintCallGraphPass Implementation 594//===----------------------------------------------------------------------===// 595 596namespace { 597 /// PrintCallGraphPass - Print a Module corresponding to a call graph. 598 /// 599 class PrintCallGraphPass : public CallGraphSCCPass { 600 std::string Banner; 601 raw_ostream &Out; // raw_ostream to print on. 602 603 public: 604 static char ID; 605 PrintCallGraphPass(const std::string &B, raw_ostream &o) 606 : CallGraphSCCPass(ID), Banner(B), Out(o) {} 607 608 void getAnalysisUsage(AnalysisUsage &AU) const override { 609 AU.setPreservesAll(); 610 } 611 612 bool runOnSCC(CallGraphSCC &SCC) override { 613 Out << Banner; 614 for (CallGraphNode *CGN : SCC) { 615 if (CGN->getFunction()) 616 CGN->getFunction()->print(Out); 617 else 618 Out << "\nPrinting <null> Function\n"; 619 } 620 return false; 621 } 622 }; 623 624} // end anonymous namespace. 625 626char PrintCallGraphPass::ID = 0; 627 628Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &O, 629 const std::string &Banner) const { 630 return new PrintCallGraphPass(Banner, O); 631} 632 633