Line data Source code
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/DenseMap.h"
20 : #include "llvm/ADT/SCCIterator.h"
21 : #include "llvm/ADT/Statistic.h"
22 : #include "llvm/Analysis/CallGraph.h"
23 : #include "llvm/IR/CallSite.h"
24 : #include "llvm/IR/Function.h"
25 : #include "llvm/IR/IRPrintingPasses.h"
26 : #include "llvm/IR/Intrinsics.h"
27 : #include "llvm/IR/LLVMContext.h"
28 : #include "llvm/IR/LegacyPassManagers.h"
29 : #include "llvm/IR/Module.h"
30 : #include "llvm/IR/OptBisect.h"
31 : #include "llvm/IR/PassTimingInfo.h"
32 : #include "llvm/Pass.h"
33 : #include "llvm/Support/CommandLine.h"
34 : #include "llvm/Support/Debug.h"
35 : #include "llvm/Support/Timer.h"
36 : #include "llvm/Support/raw_ostream.h"
37 : #include <cassert>
38 : #include <string>
39 : #include <utility>
40 : #include <vector>
41 :
42 : using namespace llvm;
43 :
44 : #define DEBUG_TYPE "cgscc-passmgr"
45 :
46 : static cl::opt<unsigned>
47 : MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4));
48 :
49 : STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC");
50 :
51 : //===----------------------------------------------------------------------===//
52 : // CGPassManager
53 : //
54 : /// CGPassManager manages FPPassManagers and CallGraphSCCPasses.
55 :
56 : namespace {
57 :
58 : class CGPassManager : public ModulePass, public PMDataManager {
59 : public:
60 : static char ID;
61 :
62 42604 : explicit CGPassManager() : ModulePass(ID), PMDataManager() {}
63 :
64 : /// Execute all of the passes scheduled for execution. Keep track of
65 : /// whether any of the passes modifies the module, and if so, return true.
66 : bool runOnModule(Module &M) override;
67 :
68 : using ModulePass::doInitialization;
69 : using ModulePass::doFinalization;
70 :
71 : bool doInitialization(CallGraph &CG);
72 : bool doFinalization(CallGraph &CG);
73 :
74 : /// Pass Manager itself does not invalidate any analysis info.
75 21302 : void getAnalysisUsage(AnalysisUsage &Info) const override {
76 : // CGPassManager walks SCC and it needs CallGraph.
77 : Info.addRequired<CallGraphWrapperPass>();
78 : Info.setPreservesAll();
79 21302 : }
80 :
81 2 : StringRef getPassName() const override { return "CallGraph Pass Manager"; }
82 :
83 21372 : PMDataManager *getAsPMDataManager() override { return this; }
84 591901 : Pass *getAsPass() override { return this; }
85 :
86 : // Print passes managed by this manager
87 12 : void dumpPassStructure(unsigned Offset) override {
88 12 : errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n";
89 48 : for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
90 : Pass *P = getContainedPass(Index);
91 36 : P->dumpPassStructure(Offset + 1);
92 36 : dumpLastUses(P, Offset+1);
93 : }
94 12 : }
95 :
96 : Pass *getContainedPass(unsigned N) {
97 : assert(N < PassVector.size() && "Pass number out of range!");
98 1342138 : return static_cast<Pass *>(PassVector[N]);
99 : }
100 :
101 53390 : PassManagerType getPassManagerType() const override {
102 53390 : return PMT_CallGraphPassManager;
103 : }
104 :
105 : private:
106 : bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
107 : bool &DevirtualizedCall);
108 :
109 : bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
110 : CallGraph &CG, bool &CallGraphUpToDate,
111 : bool &DevirtualizedCall);
112 : bool RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,
113 : bool IsCheckingMode);
114 : };
115 :
116 : } // end anonymous namespace.
117 :
118 : char CGPassManager::ID = 0;
119 :
120 1277368 : bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
121 : CallGraph &CG, bool &CallGraphUpToDate,
122 : bool &DevirtualizedCall) {
123 : bool Changed = false;
124 1277368 : PMDataManager *PM = P->getAsPMDataManager();
125 1277368 : Module &M = CG.getModule();
126 :
127 1277368 : if (!PM) {
128 : CallGraphSCCPass *CGSP = (CallGraphSCCPass *)P;
129 1165567 : if (!CallGraphUpToDate) {
130 19373 : DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
131 19373 : CallGraphUpToDate = true;
132 : }
133 :
134 : {
135 : unsigned InstrCount, SCCCount = 0;
136 1165567 : StringMap<std::pair<unsigned, unsigned>> FunctionToInstrCount;
137 1165567 : bool EmitICRemark = M.shouldEmitInstrCountChangedRemark();
138 1165567 : TimeRegion PassTimer(getPassTimer(CGSP));
139 1165567 : if (EmitICRemark)
140 6 : InstrCount = initSizeRemarkInfo(M, FunctionToInstrCount);
141 1165567 : Changed = CGSP->runOnSCC(CurSCC);
142 :
143 1165567 : if (EmitICRemark) {
144 : // FIXME: Add getInstructionCount to CallGraphSCC.
145 6 : SCCCount = M.getInstructionCount();
146 : // Is there a difference in the number of instructions in the module?
147 6 : if (SCCCount != InstrCount) {
148 : // Yep. Emit a remark and update InstrCount.
149 1 : int64_t Delta =
150 1 : static_cast<int64_t>(SCCCount) - static_cast<int64_t>(InstrCount);
151 1 : emitInstrCountChangedRemark(P, M, Delta, InstrCount,
152 : FunctionToInstrCount);
153 : InstrCount = SCCCount;
154 : }
155 : }
156 : }
157 :
158 : // After the CGSCCPass is done, when assertions are enabled, use
159 : // RefreshCallGraph to verify that the callgraph was correctly updated.
160 : #ifndef NDEBUG
161 : if (Changed)
162 : RefreshCallGraph(CurSCC, CG, true);
163 : #endif
164 :
165 1165567 : return Changed;
166 : }
167 :
168 : assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
169 : "Invalid CGPassManager member");
170 : FPPassManager *FPP = (FPPassManager*)P;
171 :
172 : // Run pass P on all functions in the current SCC.
173 223912 : for (CallGraphNode *CGN : CurSCC) {
174 112120 : if (Function *F = CGN->getFunction()) {
175 105185 : dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
176 : {
177 105185 : TimeRegion PassTimer(getPassTimer(FPP));
178 105185 : Changed |= FPP->runOnFunction(*F);
179 : }
180 105176 : F->getContext().yield();
181 : }
182 : }
183 :
184 : // The function pass(es) modified the IR, they may have clobbered the
185 : // callgraph.
186 111792 : if (Changed && CallGraphUpToDate) {
187 : LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: " << P->getPassName()
188 : << '\n');
189 69185 : CallGraphUpToDate = false;
190 : }
191 : return Changed;
192 : }
193 :
194 : /// Scan the functions in the specified CFG and resync the
195 : /// callgraph with the call sites found in it. This is used after
196 : /// FunctionPasses have potentially munged the callgraph, and can be used after
197 : /// CallGraphSCC passes to verify that they correctly updated the callgraph.
198 : ///
199 : /// This function returns true if it devirtualized an existing function call,
200 : /// meaning it turned an indirect call into a direct call. This happens when
201 : /// a function pass like GVN optimizes away stuff feeding the indirect call.
202 : /// This never happens in checking mode.
203 69185 : bool CGPassManager::RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,
204 : bool CheckingMode) {
205 : DenseMap<Value*, CallGraphNode*> CallSites;
206 :
207 : LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()
208 : << " nodes:\n";
209 : for (CallGraphNode *CGN
210 : : CurSCC) CGN->dump(););
211 :
212 : bool MadeChange = false;
213 : bool DevirtualizedCall = false;
214 :
215 : // Scan all functions in the SCC.
216 : unsigned FunctionNo = 0;
217 69330 : for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end();
218 138515 : SCCIdx != E; ++SCCIdx, ++FunctionNo) {
219 69330 : CallGraphNode *CGN = *SCCIdx;
220 69330 : Function *F = CGN->getFunction();
221 69330 : if (!F || F->isDeclaration()) continue;
222 :
223 : // Walk the function body looking for call sites. Sync up the call sites in
224 : // CGN with those actually in the function.
225 :
226 : // Keep track of the number of direct and indirect calls that were
227 : // invalidated and removed.
228 : unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0;
229 :
230 : // Get the set of call sites currently in the function.
231 212413 : for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ) {
232 : // If this call site is null, then the function pass deleted the call
233 : // entirely and the WeakTrackingVH nulled it out.
234 : if (!I->first ||
235 : // If we've already seen this call site, then the FunctionPass RAUW'd
236 : // one call with another, which resulted in two "uses" in the edge
237 : // list of the same call.
238 279205 : CallSites.count(I->first) ||
239 :
240 : // If the call edge is not from a call or invoke, or it is a
241 : // instrinsic call, then the function pass RAUW'd a call with
242 : // another value. This can happen when constant folding happens
243 : // of well known functions etc.
244 144169 : !CallSite(I->first) ||
245 127345 : (CallSite(I->first).getCalledFunction() &&
246 6 : CallSite(I->first).getCalledFunction()->isIntrinsic() &&
247 6 : Intrinsic::isLeaf(
248 : CallSite(I->first).getCalledFunction()->getIntrinsicID()))) {
249 : assert(!CheckingMode &&
250 : "CallGraphSCCPass did not update the CallGraph correctly!");
251 :
252 : // If this was an indirect call site, count it.
253 5379 : if (!I->second->getFunction())
254 170 : ++NumIndirectRemoved;
255 : else
256 5209 : ++NumDirectRemoved;
257 :
258 : // Just remove the edge from the set of callees, keep track of whether
259 : // I points to the last element of the vector.
260 : bool WasLast = I + 1 == E;
261 5379 : CGN->removeCallEdge(I);
262 :
263 : // If I pointed to the last element of the vector, we have to bail out:
264 : // iterator checking rejects comparisons of the resultant pointer with
265 : // end.
266 5379 : if (WasLast)
267 : break;
268 : E = CGN->end();
269 : continue;
270 : }
271 :
272 : assert(!CallSites.count(I->first) &&
273 : "Call site occurs in node multiple times");
274 :
275 : CallSite CS(I->first);
276 138790 : if (CS) {
277 : Function *Callee = CS.getCalledFunction();
278 : // Ignore intrinsics because they're not really function calls.
279 127343 : if (!Callee || !(Callee->isIntrinsic()))
280 277572 : CallSites.insert(std::make_pair(I->first, I->second));
281 : }
282 : ++I;
283 : }
284 :
285 : // Loop over all of the instructions in the function, getting the callsites.
286 : // Keep track of the number of direct/indirect calls added.
287 : unsigned NumDirectAdded = 0, NumIndirectAdded = 0;
288 :
289 367950 : for (BasicBlock &BB : *F)
290 3789415 : for (Instruction &I : BB) {
291 : CallSite CS(&I);
292 3975675 : if (!CS) continue;
293 : Function *Callee = CS.getCalledFunction();
294 473856 : if (Callee && Callee->isIntrinsic()) continue;
295 :
296 : // If this call site already existed in the callgraph, just verify it
297 : // matches up to expectations and remove it from CallSites.
298 : DenseMap<Value*, CallGraphNode*>::iterator ExistingIt =
299 139249 : CallSites.find(CS.getInstruction());
300 139249 : if (ExistingIt != CallSites.end()) {
301 138786 : CallGraphNode *ExistingNode = ExistingIt->second;
302 :
303 : // Remove from CallSites since we have now seen it.
304 : CallSites.erase(ExistingIt);
305 :
306 : // Verify that the callee is right.
307 150233 : if (ExistingNode->getFunction() == CS.getCalledFunction())
308 : continue;
309 :
310 : // If we are in checking mode, we are not allowed to actually mutate
311 : // the callgraph. If this is a case where we can infer that the
312 : // callgraph is less precise than it could be (e.g. an indirect call
313 : // site could be turned direct), don't reject it in checking mode, and
314 : // don't tweak it to be more precise.
315 124 : if (CheckingMode && CS.getCalledFunction() &&
316 : ExistingNode->getFunction() == nullptr)
317 : continue;
318 :
319 : assert(!CheckingMode &&
320 : "CallGraphSCCPass did not update the CallGraph correctly!");
321 :
322 : // If not, we either went from a direct call to indirect, indirect to
323 : // direct, or direct to different direct.
324 : CallGraphNode *CalleeNode;
325 : if (Function *Callee = CS.getCalledFunction()) {
326 124 : CalleeNode = CG.getOrInsertFunction(Callee);
327 : // Keep track of whether we turned an indirect call into a direct
328 : // one.
329 124 : if (!ExistingNode->getFunction()) {
330 : DevirtualizedCall = true;
331 : LLVM_DEBUG(dbgs() << " CGSCCPASSMGR: Devirtualized call to '"
332 : << Callee->getName() << "'\n");
333 : }
334 : } else {
335 : CalleeNode = CG.getCallsExternalNode();
336 : }
337 :
338 : // Update the edge target in CGN.
339 124 : CGN->replaceCallEdge(CS, CS, CalleeNode);
340 : MadeChange = true;
341 124 : continue;
342 : }
343 :
344 : assert(!CheckingMode &&
345 : "CallGraphSCCPass did not update the CallGraph correctly!");
346 :
347 : // If the call site didn't exist in the CGN yet, add it.
348 : CallGraphNode *CalleeNode;
349 : if (Function *Callee = CS.getCalledFunction()) {
350 423 : CalleeNode = CG.getOrInsertFunction(Callee);
351 423 : ++NumDirectAdded;
352 : } else {
353 : CalleeNode = CG.getCallsExternalNode();
354 40 : ++NumIndirectAdded;
355 : }
356 :
357 463 : CGN->addCalledFunction(CS, CalleeNode);
358 : MadeChange = true;
359 : }
360 :
361 : // We scanned the old callgraph node, removing invalidated call sites and
362 : // then added back newly found call sites. One thing that can happen is
363 : // that an old indirect call site was deleted and replaced with a new direct
364 : // call. In this case, we have devirtualized a call, and CGSCCPM would like
365 : // to iteratively optimize the new code. Unfortunately, we don't really
366 : // have a great way to detect when this happens. As an approximation, we
367 : // just look at whether the number of indirect calls is reduced and the
368 : // number of direct calls is increased. There are tons of ways to fool this
369 : // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a
370 : // direct call) but this is close enough.
371 138660 : if (NumIndirectRemoved > NumIndirectAdded &&
372 69330 : NumDirectRemoved < NumDirectAdded)
373 : DevirtualizedCall = true;
374 :
375 : // After scanning this function, if we still have entries in callsites, then
376 : // they are dangling pointers. WeakTrackingVH should save us for this, so
377 : // abort if
378 : // this happens.
379 : assert(CallSites.empty() && "Dangling pointers found in call sites map");
380 :
381 : // Periodically do an explicit clear to remove tombstones when processing
382 : // large scc's.
383 69330 : if ((FunctionNo & 15) == 15)
384 2 : CallSites.clear();
385 : }
386 :
387 : LLVM_DEBUG(if (MadeChange) {
388 : dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n";
389 : for (CallGraphNode *CGN : CurSCC)
390 : CGN->dump();
391 : if (DevirtualizedCall)
392 : dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n";
393 : } else {
394 : dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n";
395 : });
396 : (void)MadeChange;
397 :
398 69185 : return DevirtualizedCall;
399 : }
400 :
401 : /// Execute the body of the entire pass manager on the specified SCC.
402 : /// This keeps track of whether a function pass devirtualizes
403 : /// any calls and returns it in DevirtualizedCall.
404 1029327 : bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
405 : bool &DevirtualizedCall) {
406 : bool Changed = false;
407 :
408 : // Keep track of whether the callgraph is known to be up-to-date or not.
409 : // The CGSSC pass manager runs two types of passes:
410 : // CallGraphSCC Passes and other random function passes. Because other
411 : // random function passes are not CallGraph aware, they may clobber the
412 : // call graph by introducing new calls or deleting other ones. This flag
413 : // is set to false when we run a function pass so that we know to clean up
414 : // the callgraph when we need to run a CGSCCPass again.
415 1029327 : bool CallGraphUpToDate = true;
416 :
417 : // Run all passes on current SCC.
418 1277359 : for (unsigned PassNo = 0, e = getNumContainedPasses();
419 2306686 : PassNo != e; ++PassNo) {
420 : Pass *P = getContainedPass(PassNo);
421 :
422 : // If we're in -debug-pass=Executions mode, construct the SCC node list,
423 : // otherwise avoid constructing this string as it is expensive.
424 1277368 : if (isPassDebuggingExecutionsOrMore()) {
425 : std::string Functions;
426 : #ifndef NDEBUG
427 : raw_string_ostream OS(Functions);
428 : for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end();
429 : I != E; ++I) {
430 : if (I != CurSCC.begin()) OS << ", ";
431 : (*I)->print(OS);
432 : }
433 : OS.flush();
434 : #endif
435 4 : dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions);
436 : }
437 1277368 : dumpRequiredSet(P);
438 :
439 1277368 : initializeAnalysisImpl(P);
440 :
441 : // Actually run this pass on the current SCC.
442 1277368 : Changed |= RunPassOnSCC(P, CurSCC, CG,
443 : CallGraphUpToDate, DevirtualizedCall);
444 :
445 1277359 : if (Changed)
446 572505 : dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
447 1277359 : dumpPreservedSet(P);
448 :
449 1277359 : verifyPreservedAnalysis(P);
450 1277359 : removeNotPreservedAnalysis(P);
451 1277359 : recordAvailableAnalysis(P);
452 1277359 : removeDeadPasses(P, "", ON_CG_MSG);
453 : }
454 :
455 : // If the callgraph was left out of date (because the last pass run was a
456 : // functionpass), refresh it before we move on to the next SCC.
457 1029318 : if (!CallGraphUpToDate)
458 49812 : DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
459 1029318 : return Changed;
460 : }
461 :
462 : /// Execute all of the passes scheduled for execution. Keep track of
463 : /// whether any of the passes modifies the module, and if so, return true.
464 21292 : bool CGPassManager::runOnModule(Module &M) {
465 21292 : CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
466 21292 : bool Changed = doInitialization(CG);
467 :
468 : // Walk the callgraph in bottom-up SCC order.
469 21283 : scc_iterator<CallGraph*> CGI = scc_begin(&CG);
470 :
471 : CallGraphSCC CurSCC(CG, &CGI);
472 1050537 : while (!CGI.isAtEnd()) {
473 : // Copy the current SCC and increment past it so that the pass can hack
474 : // on the SCC if it wants to without invalidating our iterator.
475 : const std::vector<CallGraphNode *> &NodeVec = *CGI;
476 : CurSCC.initialize(NodeVec);
477 : ++CGI;
478 :
479 : // At the top level, we run all the passes in this pass manager on the
480 : // functions in this SCC. However, we support iterative compilation in the
481 : // case where a function pass devirtualizes a call to a function. For
482 : // example, it is very common for a function pass (often GVN or instcombine)
483 : // to eliminate the addressing that feeds into a call. With that improved
484 : // information, we would like the call to be an inline candidate, infer
485 : // mod-ref information etc.
486 : //
487 : // Because of this, we allow iteration up to a specified iteration count.
488 : // This only happens in the case of a devirtualized call, so we only burn
489 : // compile time in the case that we're making progress. We also have a hard
490 : // iteration count limit in case there is crazy code.
491 : unsigned Iteration = 0;
492 : bool DevirtualizedCall = false;
493 : do {
494 : LLVM_DEBUG(if (Iteration) dbgs()
495 : << " SCCPASSMGR: Re-visiting SCC, iteration #" << Iteration
496 : << '\n');
497 1029327 : DevirtualizedCall = false;
498 1029327 : Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);
499 2058636 : } while (Iteration++ < MaxIterations && DevirtualizedCall);
500 :
501 : if (DevirtualizedCall)
502 : LLVM_DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after "
503 : << Iteration
504 : << " times, due to -max-cg-scc-iterations\n");
505 :
506 : MaxSCCIterations.updateMax(Iteration);
507 : }
508 21283 : Changed |= doFinalization(CG);
509 21283 : return Changed;
510 : }
511 :
512 : /// Initialize CG
513 21292 : bool CGPassManager::doInitialization(CallGraph &CG) {
514 : bool Changed = false;
515 53659 : for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {
516 32367 : if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
517 : assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
518 : "Invalid CGPassManager member");
519 5923 : Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule());
520 : } else {
521 26444 : Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG);
522 : }
523 : }
524 21292 : return Changed;
525 : }
526 :
527 : /// Finalize CG
528 21283 : bool CGPassManager::doFinalization(CallGraph &CG) {
529 : bool Changed = false;
530 53614 : for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {
531 32331 : if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
532 : assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
533 : "Invalid CGPassManager member");
534 5905 : Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule());
535 : } else {
536 26426 : Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG);
537 : }
538 : }
539 21283 : return Changed;
540 : }
541 :
542 : //===----------------------------------------------------------------------===//
543 : // CallGraphSCC Implementation
544 : //===----------------------------------------------------------------------===//
545 :
546 : /// This informs the SCC and the pass manager that the specified
547 : /// Old node has been deleted, and New is to be used in its place.
548 42 : void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) {
549 : assert(Old != New && "Should not replace node with self");
550 0 : for (unsigned i = 0; ; ++i) {
551 0 : assert(i != Nodes.size() && "Node not in SCC");
552 84 : if (Nodes[i] != Old) continue;
553 42 : Nodes[i] = New;
554 : break;
555 : }
556 :
557 : // Update the active scc_iterator so that it doesn't contain dangling
558 : // pointers to the old CallGraphNode.
559 42 : scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;
560 42 : CGI->ReplaceNode(Old, New);
561 42 : }
562 :
563 : //===----------------------------------------------------------------------===//
564 : // CallGraphSCCPass Implementation
565 : //===----------------------------------------------------------------------===//
566 :
567 : /// Assign pass manager to manage this pass.
568 26471 : void CallGraphSCCPass::assignPassManager(PMStack &PMS,
569 : PassManagerType PreferredType) {
570 : // Find CGPassManager
571 28431 : while (!PMS.empty() &&
572 28431 : PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
573 1960 : PMS.pop();
574 :
575 : assert(!PMS.empty() && "Unable to handle Call Graph Pass");
576 : CGPassManager *CGP;
577 :
578 26471 : if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager)
579 5169 : CGP = (CGPassManager*)PMS.top();
580 : else {
581 : // Create new Call Graph SCC Pass Manager if it does not exist.
582 : assert(!PMS.empty() && "Unable to create Call Graph Pass Manager");
583 : PMDataManager *PMD = PMS.top();
584 :
585 : // [1] Create new Call Graph Pass Manager
586 21302 : CGP = new CGPassManager();
587 :
588 : // [2] Set up new manager's top level manager
589 21302 : PMTopLevelManager *TPM = PMD->getTopLevelManager();
590 21302 : TPM->addIndirectPassManager(CGP);
591 :
592 : // [3] Assign manager to manage this new manager. This may create
593 : // and push new managers into PMS
594 : Pass *P = CGP;
595 21302 : TPM->schedulePass(P);
596 :
597 : // [4] Push new manager into PMS
598 21302 : PMS.push(CGP);
599 : }
600 :
601 26471 : CGP->add(this);
602 26471 : }
603 :
604 : /// For this class, we declare that we require and preserve the call graph.
605 : /// If the derived class implements this method, it should
606 : /// always explicitly call the implementation here.
607 24500 : void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
608 : AU.addRequired<CallGraphWrapperPass>();
609 : AU.addPreserved<CallGraphWrapperPass>();
610 24500 : }
611 :
612 : //===----------------------------------------------------------------------===//
613 : // PrintCallGraphPass Implementation
614 : //===----------------------------------------------------------------------===//
615 :
616 : namespace {
617 :
618 : /// PrintCallGraphPass - Print a Module corresponding to a call graph.
619 : ///
620 : class PrintCallGraphPass : public CallGraphSCCPass {
621 : std::string Banner;
622 : raw_ostream &OS; // raw_ostream to print on.
623 :
624 : public:
625 : static char ID;
626 :
627 : PrintCallGraphPass(const std::string &B, raw_ostream &OS)
628 12 : : CallGraphSCCPass(ID), Banner(B), OS(OS) {}
629 :
630 6 : void getAnalysisUsage(AnalysisUsage &AU) const override {
631 : AU.setPreservesAll();
632 6 : }
633 :
634 14 : bool runOnSCC(CallGraphSCC &SCC) override {
635 14 : bool BannerPrinted = false;
636 : auto PrintBannerOnce = [&] () {
637 : if (BannerPrinted)
638 : return;
639 : OS << Banner;
640 : BannerPrinted = true;
641 14 : };
642 30 : for (CallGraphNode *CGN : SCC) {
643 16 : if (Function *F = CGN->getFunction()) {
644 10 : if (!F->isDeclaration() && isFunctionInPrintList(F->getName())) {
645 10 : PrintBannerOnce();
646 10 : F->print(OS);
647 : }
648 6 : } else if (isFunctionInPrintList("*")) {
649 6 : PrintBannerOnce();
650 6 : OS << "\nPrinting <null> Function\n";
651 : }
652 : }
653 14 : return false;
654 : }
655 :
656 0 : StringRef getPassName() const override { return "Print CallGraph IR"; }
657 : };
658 :
659 : } // end anonymous namespace.
660 :
661 : char PrintCallGraphPass::ID = 0;
662 :
663 6 : Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &OS,
664 : const std::string &Banner) const {
665 6 : return new PrintCallGraphPass(Banner, OS);
666 : }
667 :
668 165106 : bool CallGraphSCCPass::skipSCC(CallGraphSCC &SCC) const {
669 165106 : return !SCC.getCallGraph().getModule()
670 165106 : .getContext()
671 165106 : .getOptPassGate()
672 165106 : .shouldRunPass(this, SCC);
673 : }
674 :
675 : char DummyCGSCCPass::ID = 0;
676 :
677 3940 : INITIALIZE_PASS(DummyCGSCCPass, "DummyCGSCCPass", "DummyCGSCCPass", false,
678 : false)
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