[TableGen] Fix validateOperandClass for non Phyical Reg (#118146)
[llvm-project.git] / llvm / lib / Analysis / CGSCCPassManager.cpp
blob948bc2435ab275b8fb7f09a04c85633a1c950b18
1 //===- CGSCCPassManager.cpp - Managing & running CGSCC passes -------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
9 #include "llvm/Analysis/CGSCCPassManager.h"
10 #include "llvm/ADT/ArrayRef.h"
11 #include "llvm/ADT/PriorityWorklist.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/ADT/SetVector.h"
14 #include "llvm/ADT/SmallPtrSet.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/ADT/iterator_range.h"
17 #include "llvm/Analysis/LazyCallGraph.h"
18 #include "llvm/IR/Constant.h"
19 #include "llvm/IR/InstIterator.h"
20 #include "llvm/IR/Instruction.h"
21 #include "llvm/IR/PassManager.h"
22 #include "llvm/IR/PassManagerImpl.h"
23 #include "llvm/IR/ValueHandle.h"
24 #include "llvm/Support/Casting.h"
25 #include "llvm/Support/CommandLine.h"
26 #include "llvm/Support/Debug.h"
27 #include "llvm/Support/ErrorHandling.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include <cassert>
30 #include <optional>
32 #define DEBUG_TYPE "cgscc"
34 using namespace llvm;
36 // Explicit template instantiations and specialization definitions for core
37 // template typedefs.
38 namespace llvm {
39 static cl::opt<bool> AbortOnMaxDevirtIterationsReached(
40 "abort-on-max-devirt-iterations-reached",
41 cl::desc("Abort when the max iterations for devirtualization CGSCC repeat "
42 "pass is reached"));
44 AnalysisKey ShouldNotRunFunctionPassesAnalysis::Key;
46 // Explicit instantiations for the core proxy templates.
47 template class AllAnalysesOn<LazyCallGraph::SCC>;
48 template class AnalysisManager<LazyCallGraph::SCC, LazyCallGraph &>;
49 template class PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager,
50 LazyCallGraph &, CGSCCUpdateResult &>;
51 template class InnerAnalysisManagerProxy<CGSCCAnalysisManager, Module>;
52 template class OuterAnalysisManagerProxy<ModuleAnalysisManager,
53 LazyCallGraph::SCC, LazyCallGraph &>;
54 template class OuterAnalysisManagerProxy<CGSCCAnalysisManager, Function>;
56 /// Explicitly specialize the pass manager run method to handle call graph
57 /// updates.
58 template <>
59 PreservedAnalyses
60 PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager, LazyCallGraph &,
61 CGSCCUpdateResult &>::run(LazyCallGraph::SCC &InitialC,
62 CGSCCAnalysisManager &AM,
63 LazyCallGraph &G, CGSCCUpdateResult &UR) {
64 // Request PassInstrumentation from analysis manager, will use it to run
65 // instrumenting callbacks for the passes later.
66 PassInstrumentation PI =
67 AM.getResult<PassInstrumentationAnalysis>(InitialC, G);
69 PreservedAnalyses PA = PreservedAnalyses::all();
71 // The SCC may be refined while we are running passes over it, so set up
72 // a pointer that we can update.
73 LazyCallGraph::SCC *C = &InitialC;
75 // Get Function analysis manager from its proxy.
76 FunctionAnalysisManager &FAM =
77 AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(*C)->getManager();
79 for (auto &Pass : Passes) {
80 // Check the PassInstrumentation's BeforePass callbacks before running the
81 // pass, skip its execution completely if asked to (callback returns false).
82 if (!PI.runBeforePass(*Pass, *C))
83 continue;
85 PreservedAnalyses PassPA = Pass->run(*C, AM, G, UR);
87 // Update the SCC if necessary.
88 C = UR.UpdatedC ? UR.UpdatedC : C;
89 if (UR.UpdatedC) {
90 // If C is updated, also create a proxy and update FAM inside the result.
91 auto *ResultFAMCP =
92 &AM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, G);
93 ResultFAMCP->updateFAM(FAM);
96 // Intersect the final preserved analyses to compute the aggregate
97 // preserved set for this pass manager.
98 PA.intersect(PassPA);
100 // If the CGSCC pass wasn't able to provide a valid updated SCC, the
101 // current SCC may simply need to be skipped if invalid.
102 if (UR.InvalidatedSCCs.count(C)) {
103 PI.runAfterPassInvalidated<LazyCallGraph::SCC>(*Pass, PassPA);
104 LLVM_DEBUG(dbgs() << "Skipping invalidated root or island SCC!\n");
105 break;
108 // Check that we didn't miss any update scenario.
109 assert(C->begin() != C->end() && "Cannot have an empty SCC!");
111 // Update the analysis manager as each pass runs and potentially
112 // invalidates analyses.
113 AM.invalidate(*C, PassPA);
115 PI.runAfterPass<LazyCallGraph::SCC>(*Pass, *C, PassPA);
118 // Before we mark all of *this* SCC's analyses as preserved below, intersect
119 // this with the cross-SCC preserved analysis set. This is used to allow
120 // CGSCC passes to mutate ancestor SCCs and still trigger proper invalidation
121 // for them.
122 UR.CrossSCCPA.intersect(PA);
124 // Invalidation was handled after each pass in the above loop for the current
125 // SCC. Therefore, the remaining analysis results in the AnalysisManager are
126 // preserved. We mark this with a set so that we don't need to inspect each
127 // one individually.
128 PA.preserveSet<AllAnalysesOn<LazyCallGraph::SCC>>();
130 return PA;
133 PreservedAnalyses
134 ModuleToPostOrderCGSCCPassAdaptor::run(Module &M, ModuleAnalysisManager &AM) {
135 // Setup the CGSCC analysis manager from its proxy.
136 CGSCCAnalysisManager &CGAM =
137 AM.getResult<CGSCCAnalysisManagerModuleProxy>(M).getManager();
139 // Get the call graph for this module.
140 LazyCallGraph &CG = AM.getResult<LazyCallGraphAnalysis>(M);
142 // Get Function analysis manager from its proxy.
143 FunctionAnalysisManager &FAM =
144 AM.getCachedResult<FunctionAnalysisManagerModuleProxy>(M)->getManager();
146 // We keep worklists to allow us to push more work onto the pass manager as
147 // the passes are run.
148 SmallPriorityWorklist<LazyCallGraph::RefSCC *, 1> RCWorklist;
149 SmallPriorityWorklist<LazyCallGraph::SCC *, 1> CWorklist;
151 // Keep sets for invalidated SCCs that should be skipped when
152 // iterating off the worklists.
153 SmallPtrSet<LazyCallGraph::SCC *, 4> InvalidSCCSet;
155 SmallDenseSet<std::pair<LazyCallGraph::Node *, LazyCallGraph::SCC *>, 4>
156 InlinedInternalEdges;
158 SmallVector<Function *, 4> DeadFunctions;
160 CGSCCUpdateResult UR = {CWorklist,
161 InvalidSCCSet,
162 nullptr,
163 PreservedAnalyses::all(),
164 InlinedInternalEdges,
165 DeadFunctions,
166 {}};
168 // Request PassInstrumentation from analysis manager, will use it to run
169 // instrumenting callbacks for the passes later.
170 PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(M);
172 PreservedAnalyses PA = PreservedAnalyses::all();
173 CG.buildRefSCCs();
174 for (LazyCallGraph::RefSCC &RC :
175 llvm::make_early_inc_range(CG.postorder_ref_sccs())) {
176 assert(RCWorklist.empty() &&
177 "Should always start with an empty RefSCC worklist");
178 // The postorder_ref_sccs range we are walking is lazily constructed, so
179 // we only push the first one onto the worklist. The worklist allows us
180 // to capture *new* RefSCCs created during transformations.
182 // We really want to form RefSCCs lazily because that makes them cheaper
183 // to update as the program is simplified and allows us to have greater
184 // cache locality as forming a RefSCC touches all the parts of all the
185 // functions within that RefSCC.
187 // We also eagerly increment the iterator to the next position because
188 // the CGSCC passes below may delete the current RefSCC.
189 RCWorklist.insert(&RC);
191 do {
192 LazyCallGraph::RefSCC *RC = RCWorklist.pop_back_val();
193 assert(CWorklist.empty() &&
194 "Should always start with an empty SCC worklist");
196 LLVM_DEBUG(dbgs() << "Running an SCC pass across the RefSCC: " << *RC
197 << "\n");
199 // The top of the worklist may *also* be the same SCC we just ran over
200 // (and invalidated for). Keep track of that last SCC we processed due
201 // to SCC update to avoid redundant processing when an SCC is both just
202 // updated itself and at the top of the worklist.
203 LazyCallGraph::SCC *LastUpdatedC = nullptr;
205 // Push the initial SCCs in reverse post-order as we'll pop off the
206 // back and so see this in post-order.
207 for (LazyCallGraph::SCC &C : llvm::reverse(*RC))
208 CWorklist.insert(&C);
210 do {
211 LazyCallGraph::SCC *C = CWorklist.pop_back_val();
212 // Due to call graph mutations, we may have invalid SCCs or SCCs from
213 // other RefSCCs in the worklist. The invalid ones are dead and the
214 // other RefSCCs should be queued above, so we just need to skip both
215 // scenarios here.
216 if (InvalidSCCSet.count(C)) {
217 LLVM_DEBUG(dbgs() << "Skipping an invalid SCC...\n");
218 continue;
220 if (LastUpdatedC == C) {
221 LLVM_DEBUG(dbgs() << "Skipping redundant run on SCC: " << *C << "\n");
222 continue;
224 // We used to also check if the current SCC is part of the current
225 // RefSCC and bail if it wasn't, since it should be in RCWorklist.
226 // However, this can cause compile time explosions in some cases on
227 // modules with a huge RefSCC. If a non-trivial amount of SCCs in the
228 // huge RefSCC can become their own child RefSCC, we create one child
229 // RefSCC, bail on the current RefSCC, visit the child RefSCC, revisit
230 // the huge RefSCC, and repeat. By visiting all SCCs in the original
231 // RefSCC we create all the child RefSCCs in one pass of the RefSCC,
232 // rather one pass of the RefSCC creating one child RefSCC at a time.
234 // Ensure we can proxy analysis updates from the CGSCC analysis manager
235 // into the Function analysis manager by getting a proxy here.
236 // This also needs to update the FunctionAnalysisManager, as this may be
237 // the first time we see this SCC.
238 CGAM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, CG).updateFAM(
239 FAM);
241 // Each time we visit a new SCC pulled off the worklist,
242 // a transformation of a child SCC may have also modified this parent
243 // and invalidated analyses. So we invalidate using the update record's
244 // cross-SCC preserved set. This preserved set is intersected by any
245 // CGSCC pass that handles invalidation (primarily pass managers) prior
246 // to marking its SCC as preserved. That lets us track everything that
247 // might need invalidation across SCCs without excessive invalidations
248 // on a single SCC.
250 // This essentially allows SCC passes to freely invalidate analyses
251 // of any ancestor SCC. If this becomes detrimental to successfully
252 // caching analyses, we could force each SCC pass to manually
253 // invalidate the analyses for any SCCs other than themselves which
254 // are mutated. However, that seems to lose the robustness of the
255 // pass-manager driven invalidation scheme.
256 CGAM.invalidate(*C, UR.CrossSCCPA);
258 do {
259 // Check that we didn't miss any update scenario.
260 assert(!InvalidSCCSet.count(C) && "Processing an invalid SCC!");
261 assert(C->begin() != C->end() && "Cannot have an empty SCC!");
263 LastUpdatedC = UR.UpdatedC;
264 UR.UpdatedC = nullptr;
266 // Check the PassInstrumentation's BeforePass callbacks before
267 // running the pass, skip its execution completely if asked to
268 // (callback returns false).
269 if (!PI.runBeforePass<LazyCallGraph::SCC>(*Pass, *C))
270 continue;
272 PreservedAnalyses PassPA = Pass->run(*C, CGAM, CG, UR);
274 // Update the SCC and RefSCC if necessary.
275 C = UR.UpdatedC ? UR.UpdatedC : C;
277 if (UR.UpdatedC) {
278 // If we're updating the SCC, also update the FAM inside the proxy's
279 // result.
280 CGAM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, CG).updateFAM(
281 FAM);
284 // Intersect with the cross-SCC preserved set to capture any
285 // cross-SCC invalidation.
286 UR.CrossSCCPA.intersect(PassPA);
287 // Intersect the preserved set so that invalidation of module
288 // analyses will eventually occur when the module pass completes.
289 PA.intersect(PassPA);
291 // If the CGSCC pass wasn't able to provide a valid updated SCC,
292 // the current SCC may simply need to be skipped if invalid.
293 if (UR.InvalidatedSCCs.count(C)) {
294 PI.runAfterPassInvalidated<LazyCallGraph::SCC>(*Pass, PassPA);
295 LLVM_DEBUG(dbgs() << "Skipping invalidated root or island SCC!\n");
296 break;
299 // Check that we didn't miss any update scenario.
300 assert(C->begin() != C->end() && "Cannot have an empty SCC!");
302 // We handle invalidating the CGSCC analysis manager's information
303 // for the (potentially updated) SCC here. Note that any other SCCs
304 // whose structure has changed should have been invalidated by
305 // whatever was updating the call graph. This SCC gets invalidated
306 // late as it contains the nodes that were actively being
307 // processed.
308 CGAM.invalidate(*C, PassPA);
310 PI.runAfterPass<LazyCallGraph::SCC>(*Pass, *C, PassPA);
312 // The pass may have restructured the call graph and refined the
313 // current SCC and/or RefSCC. We need to update our current SCC and
314 // RefSCC pointers to follow these. Also, when the current SCC is
315 // refined, re-run the SCC pass over the newly refined SCC in order
316 // to observe the most precise SCC model available. This inherently
317 // cannot cycle excessively as it only happens when we split SCCs
318 // apart, at most converging on a DAG of single nodes.
319 // FIXME: If we ever start having RefSCC passes, we'll want to
320 // iterate there too.
321 if (UR.UpdatedC)
322 LLVM_DEBUG(dbgs()
323 << "Re-running SCC passes after a refinement of the "
324 "current SCC: "
325 << *UR.UpdatedC << "\n");
327 // Note that both `C` and `RC` may at this point refer to deleted,
328 // invalid SCC and RefSCCs respectively. But we will short circuit
329 // the processing when we check them in the loop above.
330 } while (UR.UpdatedC);
331 } while (!CWorklist.empty());
333 // We only need to keep internal inlined edge information within
334 // a RefSCC, clear it to save on space and let the next time we visit
335 // any of these functions have a fresh start.
336 InlinedInternalEdges.clear();
337 } while (!RCWorklist.empty());
340 CG.removeDeadFunctions(DeadFunctions);
341 for (Function *DeadF : DeadFunctions)
342 DeadF->eraseFromParent();
344 #if defined(EXPENSIVE_CHECKS)
345 // Verify that the call graph is still valid.
346 CG.verify();
347 #endif
349 // By definition we preserve the call garph, all SCC analyses, and the
350 // analysis proxies by handling them above and in any nested pass managers.
351 PA.preserveSet<AllAnalysesOn<LazyCallGraph::SCC>>();
352 PA.preserve<LazyCallGraphAnalysis>();
353 PA.preserve<CGSCCAnalysisManagerModuleProxy>();
354 PA.preserve<FunctionAnalysisManagerModuleProxy>();
355 return PA;
358 PreservedAnalyses DevirtSCCRepeatedPass::run(LazyCallGraph::SCC &InitialC,
359 CGSCCAnalysisManager &AM,
360 LazyCallGraph &CG,
361 CGSCCUpdateResult &UR) {
362 PreservedAnalyses PA = PreservedAnalyses::all();
363 PassInstrumentation PI =
364 AM.getResult<PassInstrumentationAnalysis>(InitialC, CG);
366 // The SCC may be refined while we are running passes over it, so set up
367 // a pointer that we can update.
368 LazyCallGraph::SCC *C = &InitialC;
370 // Struct to track the counts of direct and indirect calls in each function
371 // of the SCC.
372 struct CallCount {
373 int Direct;
374 int Indirect;
377 // Put value handles on all of the indirect calls and return the number of
378 // direct calls for each function in the SCC.
379 auto ScanSCC = [](LazyCallGraph::SCC &C,
380 SmallMapVector<Value *, WeakTrackingVH, 16> &CallHandles) {
381 assert(CallHandles.empty() && "Must start with a clear set of handles.");
383 SmallDenseMap<Function *, CallCount> CallCounts;
384 CallCount CountLocal = {0, 0};
385 for (LazyCallGraph::Node &N : C) {
386 CallCount &Count =
387 CallCounts.insert(std::make_pair(&N.getFunction(), CountLocal))
388 .first->second;
389 for (Instruction &I : instructions(N.getFunction()))
390 if (auto *CB = dyn_cast<CallBase>(&I)) {
391 if (CB->getCalledFunction()) {
392 ++Count.Direct;
393 } else {
394 ++Count.Indirect;
395 CallHandles.insert({CB, WeakTrackingVH(CB)});
400 return CallCounts;
403 UR.IndirectVHs.clear();
404 // Populate the initial call handles and get the initial call counts.
405 auto CallCounts = ScanSCC(*C, UR.IndirectVHs);
407 for (int Iteration = 0;; ++Iteration) {
408 if (!PI.runBeforePass<LazyCallGraph::SCC>(*Pass, *C))
409 continue;
411 PreservedAnalyses PassPA = Pass->run(*C, AM, CG, UR);
413 PA.intersect(PassPA);
415 // If the CGSCC pass wasn't able to provide a valid updated SCC, the
416 // current SCC may simply need to be skipped if invalid.
417 if (UR.InvalidatedSCCs.count(C)) {
418 PI.runAfterPassInvalidated<LazyCallGraph::SCC>(*Pass, PassPA);
419 LLVM_DEBUG(dbgs() << "Skipping invalidated root or island SCC!\n");
420 break;
423 // Update the analysis manager with each run and intersect the total set
424 // of preserved analyses so we're ready to iterate.
425 AM.invalidate(*C, PassPA);
427 PI.runAfterPass<LazyCallGraph::SCC>(*Pass, *C, PassPA);
429 // If the SCC structure has changed, bail immediately and let the outer
430 // CGSCC layer handle any iteration to reflect the refined structure.
431 if (UR.UpdatedC && UR.UpdatedC != C)
432 break;
434 assert(C->begin() != C->end() && "Cannot have an empty SCC!");
436 // Check whether any of the handles were devirtualized.
437 bool Devirt = llvm::any_of(UR.IndirectVHs, [](auto &P) -> bool {
438 if (P.second) {
439 if (CallBase *CB = dyn_cast<CallBase>(P.second)) {
440 if (CB->getCalledFunction()) {
441 LLVM_DEBUG(dbgs() << "Found devirtualized call: " << *CB << "\n");
442 return true;
446 return false;
449 // Rescan to build up a new set of handles and count how many direct
450 // calls remain. If we decide to iterate, this also sets up the input to
451 // the next iteration.
452 UR.IndirectVHs.clear();
453 auto NewCallCounts = ScanSCC(*C, UR.IndirectVHs);
455 // If we haven't found an explicit devirtualization already see if we
456 // have decreased the number of indirect calls and increased the number
457 // of direct calls for any function in the SCC. This can be fooled by all
458 // manner of transformations such as DCE and other things, but seems to
459 // work well in practice.
460 if (!Devirt)
461 // Iterate over the keys in NewCallCounts, if Function also exists in
462 // CallCounts, make the check below.
463 for (auto &Pair : NewCallCounts) {
464 auto &CallCountNew = Pair.second;
465 auto CountIt = CallCounts.find(Pair.first);
466 if (CountIt != CallCounts.end()) {
467 const auto &CallCountOld = CountIt->second;
468 if (CallCountOld.Indirect > CallCountNew.Indirect &&
469 CallCountOld.Direct < CallCountNew.Direct) {
470 Devirt = true;
471 break;
476 if (!Devirt) {
477 break;
480 // Otherwise, if we've already hit our max, we're done.
481 if (Iteration >= MaxIterations) {
482 if (AbortOnMaxDevirtIterationsReached)
483 report_fatal_error("Max devirtualization iterations reached");
484 LLVM_DEBUG(
485 dbgs() << "Found another devirtualization after hitting the max "
486 "number of repetitions ("
487 << MaxIterations << ") on SCC: " << *C << "\n");
488 break;
491 LLVM_DEBUG(
492 dbgs() << "Repeating an SCC pass after finding a devirtualization in: "
493 << *C << "\n");
495 // Move over the new call counts in preparation for iterating.
496 CallCounts = std::move(NewCallCounts);
499 // Note that we don't add any preserved entries here unlike a more normal
500 // "pass manager" because we only handle invalidation *between* iterations,
501 // not after the last iteration.
502 return PA;
505 PreservedAnalyses CGSCCToFunctionPassAdaptor::run(LazyCallGraph::SCC &C,
506 CGSCCAnalysisManager &AM,
507 LazyCallGraph &CG,
508 CGSCCUpdateResult &UR) {
509 // Setup the function analysis manager from its proxy.
510 FunctionAnalysisManager &FAM =
511 AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, CG).getManager();
513 SmallVector<LazyCallGraph::Node *, 4> Nodes;
514 for (LazyCallGraph::Node &N : C)
515 Nodes.push_back(&N);
517 // The SCC may get split while we are optimizing functions due to deleting
518 // edges. If this happens, the current SCC can shift, so keep track of
519 // a pointer we can overwrite.
520 LazyCallGraph::SCC *CurrentC = &C;
522 LLVM_DEBUG(dbgs() << "Running function passes across an SCC: " << C << "\n");
524 PreservedAnalyses PA = PreservedAnalyses::all();
525 for (LazyCallGraph::Node *N : Nodes) {
526 // Skip nodes from other SCCs. These may have been split out during
527 // processing. We'll eventually visit those SCCs and pick up the nodes
528 // there.
529 if (CG.lookupSCC(*N) != CurrentC)
530 continue;
532 Function &F = N->getFunction();
534 if (NoRerun && FAM.getCachedResult<ShouldNotRunFunctionPassesAnalysis>(F))
535 continue;
537 PassInstrumentation PI = FAM.getResult<PassInstrumentationAnalysis>(F);
538 if (!PI.runBeforePass<Function>(*Pass, F))
539 continue;
541 PreservedAnalyses PassPA = Pass->run(F, FAM);
543 // We know that the function pass couldn't have invalidated any other
544 // function's analyses (that's the contract of a function pass), so
545 // directly handle the function analysis manager's invalidation here.
546 FAM.invalidate(F, EagerlyInvalidate ? PreservedAnalyses::none() : PassPA);
548 PI.runAfterPass<Function>(*Pass, F, PassPA);
550 // Then intersect the preserved set so that invalidation of module
551 // analyses will eventually occur when the module pass completes.
552 PA.intersect(std::move(PassPA));
554 // If the call graph hasn't been preserved, update it based on this
555 // function pass. This may also update the current SCC to point to
556 // a smaller, more refined SCC.
557 auto PAC = PA.getChecker<LazyCallGraphAnalysis>();
558 if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Module>>()) {
559 CurrentC = &updateCGAndAnalysisManagerForFunctionPass(CG, *CurrentC, *N,
560 AM, UR, FAM);
561 assert(CG.lookupSCC(*N) == CurrentC &&
562 "Current SCC not updated to the SCC containing the current node!");
566 // By definition we preserve the proxy. And we preserve all analyses on
567 // Functions. This precludes *any* invalidation of function analyses by the
568 // proxy, but that's OK because we've taken care to invalidate analyses in
569 // the function analysis manager incrementally above.
570 PA.preserveSet<AllAnalysesOn<Function>>();
571 PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
573 // We've also ensured that we updated the call graph along the way.
574 PA.preserve<LazyCallGraphAnalysis>();
576 return PA;
579 bool CGSCCAnalysisManagerModuleProxy::Result::invalidate(
580 Module &M, const PreservedAnalyses &PA,
581 ModuleAnalysisManager::Invalidator &Inv) {
582 // If literally everything is preserved, we're done.
583 if (PA.areAllPreserved())
584 return false; // This is still a valid proxy.
586 // If this proxy or the call graph is going to be invalidated, we also need
587 // to clear all the keys coming from that analysis.
589 // We also directly invalidate the FAM's module proxy if necessary, and if
590 // that proxy isn't preserved we can't preserve this proxy either. We rely on
591 // it to handle module -> function analysis invalidation in the face of
592 // structural changes and so if it's unavailable we conservatively clear the
593 // entire SCC layer as well rather than trying to do invalidation ourselves.
594 auto PAC = PA.getChecker<CGSCCAnalysisManagerModuleProxy>();
595 if (!(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Module>>()) ||
596 Inv.invalidate<LazyCallGraphAnalysis>(M, PA) ||
597 Inv.invalidate<FunctionAnalysisManagerModuleProxy>(M, PA)) {
598 InnerAM->clear();
600 // And the proxy itself should be marked as invalid so that we can observe
601 // the new call graph. This isn't strictly necessary because we cheat
602 // above, but is still useful.
603 return true;
606 // Directly check if the relevant set is preserved so we can short circuit
607 // invalidating SCCs below.
608 bool AreSCCAnalysesPreserved =
609 PA.allAnalysesInSetPreserved<AllAnalysesOn<LazyCallGraph::SCC>>();
611 // Ok, we have a graph, so we can propagate the invalidation down into it.
612 G->buildRefSCCs();
613 for (auto &RC : G->postorder_ref_sccs())
614 for (auto &C : RC) {
615 std::optional<PreservedAnalyses> InnerPA;
617 // Check to see whether the preserved set needs to be adjusted based on
618 // module-level analysis invalidation triggering deferred invalidation
619 // for this SCC.
620 if (auto *OuterProxy =
621 InnerAM->getCachedResult<ModuleAnalysisManagerCGSCCProxy>(C))
622 for (const auto &OuterInvalidationPair :
623 OuterProxy->getOuterInvalidations()) {
624 AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
625 const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
626 if (Inv.invalidate(OuterAnalysisID, M, PA)) {
627 if (!InnerPA)
628 InnerPA = PA;
629 for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
630 InnerPA->abandon(InnerAnalysisID);
634 // Check if we needed a custom PA set. If so we'll need to run the inner
635 // invalidation.
636 if (InnerPA) {
637 InnerAM->invalidate(C, *InnerPA);
638 continue;
641 // Otherwise we only need to do invalidation if the original PA set didn't
642 // preserve all SCC analyses.
643 if (!AreSCCAnalysesPreserved)
644 InnerAM->invalidate(C, PA);
647 // Return false to indicate that this result is still a valid proxy.
648 return false;
651 template <>
652 CGSCCAnalysisManagerModuleProxy::Result
653 CGSCCAnalysisManagerModuleProxy::run(Module &M, ModuleAnalysisManager &AM) {
654 // Force the Function analysis manager to also be available so that it can
655 // be accessed in an SCC analysis and proxied onward to function passes.
656 // FIXME: It is pretty awkward to just drop the result here and assert that
657 // we can find it again later.
658 (void)AM.getResult<FunctionAnalysisManagerModuleProxy>(M);
660 return Result(*InnerAM, AM.getResult<LazyCallGraphAnalysis>(M));
663 AnalysisKey FunctionAnalysisManagerCGSCCProxy::Key;
665 FunctionAnalysisManagerCGSCCProxy::Result
666 FunctionAnalysisManagerCGSCCProxy::run(LazyCallGraph::SCC &C,
667 CGSCCAnalysisManager &AM,
668 LazyCallGraph &CG) {
669 // Note: unconditionally getting checking that the proxy exists may get it at
670 // this point. There are cases when this is being run unnecessarily, but
671 // it is cheap and having the assertion in place is more valuable.
672 auto &MAMProxy = AM.getResult<ModuleAnalysisManagerCGSCCProxy>(C, CG);
673 Module &M = *C.begin()->getFunction().getParent();
674 bool ProxyExists =
675 MAMProxy.cachedResultExists<FunctionAnalysisManagerModuleProxy>(M);
676 assert(ProxyExists &&
677 "The CGSCC pass manager requires that the FAM module proxy is run "
678 "on the module prior to entering the CGSCC walk");
679 (void)ProxyExists;
681 // We just return an empty result. The caller will use the updateFAM interface
682 // to correctly register the relevant FunctionAnalysisManager based on the
683 // context in which this proxy is run.
684 return Result();
687 bool FunctionAnalysisManagerCGSCCProxy::Result::invalidate(
688 LazyCallGraph::SCC &C, const PreservedAnalyses &PA,
689 CGSCCAnalysisManager::Invalidator &Inv) {
690 // If literally everything is preserved, we're done.
691 if (PA.areAllPreserved())
692 return false; // This is still a valid proxy.
694 // All updates to preserve valid results are done below, so we don't need to
695 // invalidate this proxy.
697 // Note that in order to preserve this proxy, a module pass must ensure that
698 // the FAM has been completely updated to handle the deletion of functions.
699 // Specifically, any FAM-cached results for those functions need to have been
700 // forcibly cleared. When preserved, this proxy will only invalidate results
701 // cached on functions *still in the module* at the end of the module pass.
702 auto PAC = PA.getChecker<FunctionAnalysisManagerCGSCCProxy>();
703 if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<LazyCallGraph::SCC>>()) {
704 for (LazyCallGraph::Node &N : C)
705 FAM->invalidate(N.getFunction(), PA);
707 return false;
710 // Directly check if the relevant set is preserved.
711 bool AreFunctionAnalysesPreserved =
712 PA.allAnalysesInSetPreserved<AllAnalysesOn<Function>>();
714 // Now walk all the functions to see if any inner analysis invalidation is
715 // necessary.
716 for (LazyCallGraph::Node &N : C) {
717 Function &F = N.getFunction();
718 std::optional<PreservedAnalyses> FunctionPA;
720 // Check to see whether the preserved set needs to be pruned based on
721 // SCC-level analysis invalidation that triggers deferred invalidation
722 // registered with the outer analysis manager proxy for this function.
723 if (auto *OuterProxy =
724 FAM->getCachedResult<CGSCCAnalysisManagerFunctionProxy>(F))
725 for (const auto &OuterInvalidationPair :
726 OuterProxy->getOuterInvalidations()) {
727 AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
728 const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
729 if (Inv.invalidate(OuterAnalysisID, C, PA)) {
730 if (!FunctionPA)
731 FunctionPA = PA;
732 for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
733 FunctionPA->abandon(InnerAnalysisID);
737 // Check if we needed a custom PA set, and if so we'll need to run the
738 // inner invalidation.
739 if (FunctionPA) {
740 FAM->invalidate(F, *FunctionPA);
741 continue;
744 // Otherwise we only need to do invalidation if the original PA set didn't
745 // preserve all function analyses.
746 if (!AreFunctionAnalysesPreserved)
747 FAM->invalidate(F, PA);
750 // Return false to indicate that this result is still a valid proxy.
751 return false;
754 } // end namespace llvm
756 /// When a new SCC is created for the graph we first update the
757 /// FunctionAnalysisManager in the Proxy's result.
758 /// As there might be function analysis results cached for the functions now in
759 /// that SCC, two forms of updates are required.
761 /// First, a proxy from the SCC to the FunctionAnalysisManager needs to be
762 /// created so that any subsequent invalidation events to the SCC are
763 /// propagated to the function analysis results cached for functions within it.
765 /// Second, if any of the functions within the SCC have analysis results with
766 /// outer analysis dependencies, then those dependencies would point to the
767 /// *wrong* SCC's analysis result. We forcibly invalidate the necessary
768 /// function analyses so that they don't retain stale handles.
769 static void updateNewSCCFunctionAnalyses(LazyCallGraph::SCC &C,
770 LazyCallGraph &G,
771 CGSCCAnalysisManager &AM,
772 FunctionAnalysisManager &FAM) {
773 AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, G).updateFAM(FAM);
775 // Now walk the functions in this SCC and invalidate any function analysis
776 // results that might have outer dependencies on an SCC analysis.
777 for (LazyCallGraph::Node &N : C) {
778 Function &F = N.getFunction();
780 auto *OuterProxy =
781 FAM.getCachedResult<CGSCCAnalysisManagerFunctionProxy>(F);
782 if (!OuterProxy)
783 // No outer analyses were queried, nothing to do.
784 continue;
786 // Forcibly abandon all the inner analyses with dependencies, but
787 // invalidate nothing else.
788 auto PA = PreservedAnalyses::all();
789 for (const auto &OuterInvalidationPair :
790 OuterProxy->getOuterInvalidations()) {
791 const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
792 for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
793 PA.abandon(InnerAnalysisID);
796 // Now invalidate anything we found.
797 FAM.invalidate(F, PA);
801 /// Helper function to update both the \c CGSCCAnalysisManager \p AM and the \c
802 /// CGSCCPassManager's \c CGSCCUpdateResult \p UR based on a range of newly
803 /// added SCCs.
805 /// The range of new SCCs must be in postorder already. The SCC they were split
806 /// out of must be provided as \p C. The current node being mutated and
807 /// triggering updates must be passed as \p N.
809 /// This function returns the SCC containing \p N. This will be either \p C if
810 /// no new SCCs have been split out, or it will be the new SCC containing \p N.
811 template <typename SCCRangeT>
812 static LazyCallGraph::SCC *
813 incorporateNewSCCRange(const SCCRangeT &NewSCCRange, LazyCallGraph &G,
814 LazyCallGraph::Node &N, LazyCallGraph::SCC *C,
815 CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR) {
816 using SCC = LazyCallGraph::SCC;
818 if (NewSCCRange.empty())
819 return C;
821 // Add the current SCC to the worklist as its shape has changed.
822 UR.CWorklist.insert(C);
823 LLVM_DEBUG(dbgs() << "Enqueuing the existing SCC in the worklist:" << *C
824 << "\n");
826 SCC *OldC = C;
828 // Update the current SCC. Note that if we have new SCCs, this must actually
829 // change the SCC.
830 assert(C != &*NewSCCRange.begin() &&
831 "Cannot insert new SCCs without changing current SCC!");
832 C = &*NewSCCRange.begin();
833 assert(G.lookupSCC(N) == C && "Failed to update current SCC!");
835 // If we had a cached FAM proxy originally, we will want to create more of
836 // them for each SCC that was split off.
837 FunctionAnalysisManager *FAM = nullptr;
838 if (auto *FAMProxy =
839 AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(*OldC))
840 FAM = &FAMProxy->getManager();
842 // We need to propagate an invalidation call to all but the newly current SCC
843 // because the outer pass manager won't do that for us after splitting them.
844 // FIXME: We should accept a PreservedAnalysis from the CG updater so that if
845 // there are preserved analysis we can avoid invalidating them here for
846 // split-off SCCs.
847 // We know however that this will preserve any FAM proxy so go ahead and mark
848 // that.
849 auto PA = PreservedAnalyses::allInSet<AllAnalysesOn<Function>>();
850 PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
851 AM.invalidate(*OldC, PA);
853 // Ensure the now-current SCC's function analyses are updated.
854 if (FAM)
855 updateNewSCCFunctionAnalyses(*C, G, AM, *FAM);
857 for (SCC &NewC : llvm::reverse(llvm::drop_begin(NewSCCRange))) {
858 assert(C != &NewC && "No need to re-visit the current SCC!");
859 assert(OldC != &NewC && "Already handled the original SCC!");
860 UR.CWorklist.insert(&NewC);
861 LLVM_DEBUG(dbgs() << "Enqueuing a newly formed SCC:" << NewC << "\n");
863 // Ensure new SCCs' function analyses are updated.
864 if (FAM)
865 updateNewSCCFunctionAnalyses(NewC, G, AM, *FAM);
867 // Also propagate a normal invalidation to the new SCC as only the current
868 // will get one from the pass manager infrastructure.
869 AM.invalidate(NewC, PA);
871 return C;
874 static LazyCallGraph::SCC &updateCGAndAnalysisManagerForPass(
875 LazyCallGraph &G, LazyCallGraph::SCC &InitialC, LazyCallGraph::Node &N,
876 CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR,
877 FunctionAnalysisManager &FAM, bool FunctionPass) {
878 using Node = LazyCallGraph::Node;
879 using Edge = LazyCallGraph::Edge;
880 using SCC = LazyCallGraph::SCC;
881 using RefSCC = LazyCallGraph::RefSCC;
883 RefSCC &InitialRC = InitialC.getOuterRefSCC();
884 SCC *C = &InitialC;
885 RefSCC *RC = &InitialRC;
886 Function &F = N.getFunction();
888 // Walk the function body and build up the set of retained, promoted, and
889 // demoted edges.
890 SmallVector<Constant *, 16> Worklist;
891 SmallPtrSet<Constant *, 16> Visited;
892 SmallPtrSet<Node *, 16> RetainedEdges;
893 SmallSetVector<Node *, 4> PromotedRefTargets;
894 SmallSetVector<Node *, 4> DemotedCallTargets;
895 SmallSetVector<Node *, 4> NewCallEdges;
896 SmallSetVector<Node *, 4> NewRefEdges;
898 // First walk the function and handle all called functions. We do this first
899 // because if there is a single call edge, whether there are ref edges is
900 // irrelevant.
901 for (Instruction &I : instructions(F)) {
902 if (auto *CB = dyn_cast<CallBase>(&I)) {
903 if (Function *Callee = CB->getCalledFunction()) {
904 if (Visited.insert(Callee).second && !Callee->isDeclaration()) {
905 Node *CalleeN = G.lookup(*Callee);
906 assert(CalleeN &&
907 "Visited function should already have an associated node");
908 Edge *E = N->lookup(*CalleeN);
909 assert((E || !FunctionPass) &&
910 "No function transformations should introduce *new* "
911 "call edges! Any new calls should be modeled as "
912 "promoted existing ref edges!");
913 bool Inserted = RetainedEdges.insert(CalleeN).second;
914 (void)Inserted;
915 assert(Inserted && "We should never visit a function twice.");
916 if (!E)
917 NewCallEdges.insert(CalleeN);
918 else if (!E->isCall())
919 PromotedRefTargets.insert(CalleeN);
921 } else {
922 // We can miss devirtualization if an indirect call is created then
923 // promoted before updateCGAndAnalysisManagerForPass runs.
924 auto *Entry = UR.IndirectVHs.find(CB);
925 if (Entry == UR.IndirectVHs.end())
926 UR.IndirectVHs.insert({CB, WeakTrackingVH(CB)});
927 else if (!Entry->second)
928 Entry->second = WeakTrackingVH(CB);
933 // Now walk all references.
934 for (Instruction &I : instructions(F))
935 for (Value *Op : I.operand_values())
936 if (auto *OpC = dyn_cast<Constant>(Op))
937 if (Visited.insert(OpC).second)
938 Worklist.push_back(OpC);
940 auto VisitRef = [&](Function &Referee) {
941 Node *RefereeN = G.lookup(Referee);
942 assert(RefereeN &&
943 "Visited function should already have an associated node");
944 Edge *E = N->lookup(*RefereeN);
945 assert((E || !FunctionPass) &&
946 "No function transformations should introduce *new* ref "
947 "edges! Any new ref edges would require IPO which "
948 "function passes aren't allowed to do!");
949 bool Inserted = RetainedEdges.insert(RefereeN).second;
950 (void)Inserted;
951 assert(Inserted && "We should never visit a function twice.");
952 if (!E)
953 NewRefEdges.insert(RefereeN);
954 else if (E->isCall())
955 DemotedCallTargets.insert(RefereeN);
957 LazyCallGraph::visitReferences(Worklist, Visited, VisitRef);
959 // Handle new ref edges.
960 for (Node *RefTarget : NewRefEdges) {
961 SCC &TargetC = *G.lookupSCC(*RefTarget);
962 RefSCC &TargetRC = TargetC.getOuterRefSCC();
963 (void)TargetRC;
964 // TODO: This only allows trivial edges to be added for now.
965 #ifdef EXPENSIVE_CHECKS
966 assert((RC == &TargetRC ||
967 RC->isAncestorOf(TargetRC)) && "New ref edge is not trivial!");
968 #endif
969 RC->insertTrivialRefEdge(N, *RefTarget);
972 // Handle new call edges.
973 for (Node *CallTarget : NewCallEdges) {
974 SCC &TargetC = *G.lookupSCC(*CallTarget);
975 RefSCC &TargetRC = TargetC.getOuterRefSCC();
976 (void)TargetRC;
977 // TODO: This only allows trivial edges to be added for now.
978 #ifdef EXPENSIVE_CHECKS
979 assert((RC == &TargetRC ||
980 RC->isAncestorOf(TargetRC)) && "New call edge is not trivial!");
981 #endif
982 // Add a trivial ref edge to be promoted later on alongside
983 // PromotedRefTargets.
984 RC->insertTrivialRefEdge(N, *CallTarget);
987 // Include synthetic reference edges to known, defined lib functions.
988 for (auto *LibFn : G.getLibFunctions())
989 // While the list of lib functions doesn't have repeats, don't re-visit
990 // anything handled above.
991 if (!Visited.count(LibFn))
992 VisitRef(*LibFn);
994 // First remove all of the edges that are no longer present in this function.
995 // The first step makes these edges uniformly ref edges and accumulates them
996 // into a separate data structure so removal doesn't invalidate anything.
997 SmallVector<Node *, 4> DeadTargets;
998 for (Edge &E : *N) {
999 if (RetainedEdges.count(&E.getNode()))
1000 continue;
1002 SCC &TargetC = *G.lookupSCC(E.getNode());
1003 RefSCC &TargetRC = TargetC.getOuterRefSCC();
1004 if (&TargetRC == RC && E.isCall()) {
1005 if (C != &TargetC) {
1006 // For separate SCCs this is trivial.
1007 RC->switchTrivialInternalEdgeToRef(N, E.getNode());
1008 } else {
1009 // Now update the call graph.
1010 C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, E.getNode()),
1011 G, N, C, AM, UR);
1015 // Now that this is ready for actual removal, put it into our list.
1016 DeadTargets.push_back(&E.getNode());
1018 // Remove the easy cases quickly and actually pull them out of our list.
1019 llvm::erase_if(DeadTargets, [&](Node *TargetN) {
1020 SCC &TargetC = *G.lookupSCC(*TargetN);
1021 RefSCC &TargetRC = TargetC.getOuterRefSCC();
1023 // We can't trivially remove internal targets, so skip
1024 // those.
1025 if (&TargetRC == RC)
1026 return false;
1028 LLVM_DEBUG(dbgs() << "Deleting outgoing edge from '" << N << "' to '"
1029 << *TargetN << "'\n");
1030 RC->removeOutgoingEdge(N, *TargetN);
1031 return true;
1034 // Next demote all the call edges that are now ref edges. This helps make
1035 // the SCCs small which should minimize the work below as we don't want to
1036 // form cycles that this would break.
1037 for (Node *RefTarget : DemotedCallTargets) {
1038 SCC &TargetC = *G.lookupSCC(*RefTarget);
1039 RefSCC &TargetRC = TargetC.getOuterRefSCC();
1041 // The easy case is when the target RefSCC is not this RefSCC. This is
1042 // only supported when the target RefSCC is a child of this RefSCC.
1043 if (&TargetRC != RC) {
1044 #ifdef EXPENSIVE_CHECKS
1045 assert(RC->isAncestorOf(TargetRC) &&
1046 "Cannot potentially form RefSCC cycles here!");
1047 #endif
1048 RC->switchOutgoingEdgeToRef(N, *RefTarget);
1049 LLVM_DEBUG(dbgs() << "Switch outgoing call edge to a ref edge from '" << N
1050 << "' to '" << *RefTarget << "'\n");
1051 continue;
1054 // We are switching an internal call edge to a ref edge. This may split up
1055 // some SCCs.
1056 if (C != &TargetC) {
1057 // For separate SCCs this is trivial.
1058 RC->switchTrivialInternalEdgeToRef(N, *RefTarget);
1059 continue;
1062 // Now update the call graph.
1063 C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, *RefTarget), G, N,
1064 C, AM, UR);
1067 // We added a ref edge earlier for new call edges, promote those to call edges
1068 // alongside PromotedRefTargets.
1069 for (Node *E : NewCallEdges)
1070 PromotedRefTargets.insert(E);
1072 // Now promote ref edges into call edges.
1073 for (Node *CallTarget : PromotedRefTargets) {
1074 SCC &TargetC = *G.lookupSCC(*CallTarget);
1075 RefSCC &TargetRC = TargetC.getOuterRefSCC();
1077 // The easy case is when the target RefSCC is not this RefSCC. This is
1078 // only supported when the target RefSCC is a child of this RefSCC.
1079 if (&TargetRC != RC) {
1080 #ifdef EXPENSIVE_CHECKS
1081 assert(RC->isAncestorOf(TargetRC) &&
1082 "Cannot potentially form RefSCC cycles here!");
1083 #endif
1084 RC->switchOutgoingEdgeToCall(N, *CallTarget);
1085 LLVM_DEBUG(dbgs() << "Switch outgoing ref edge to a call edge from '" << N
1086 << "' to '" << *CallTarget << "'\n");
1087 continue;
1089 LLVM_DEBUG(dbgs() << "Switch an internal ref edge to a call edge from '"
1090 << N << "' to '" << *CallTarget << "'\n");
1092 // Otherwise we are switching an internal ref edge to a call edge. This
1093 // may merge away some SCCs, and we add those to the UpdateResult. We also
1094 // need to make sure to update the worklist in the event SCCs have moved
1095 // before the current one in the post-order sequence
1096 bool HasFunctionAnalysisProxy = false;
1097 auto InitialSCCIndex = RC->find(*C) - RC->begin();
1098 bool FormedCycle = RC->switchInternalEdgeToCall(
1099 N, *CallTarget, [&](ArrayRef<SCC *> MergedSCCs) {
1100 for (SCC *MergedC : MergedSCCs) {
1101 assert(MergedC != &TargetC && "Cannot merge away the target SCC!");
1103 HasFunctionAnalysisProxy |=
1104 AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(
1105 *MergedC) != nullptr;
1107 // Mark that this SCC will no longer be valid.
1108 UR.InvalidatedSCCs.insert(MergedC);
1110 // FIXME: We should really do a 'clear' here to forcibly release
1111 // memory, but we don't have a good way of doing that and
1112 // preserving the function analyses.
1113 auto PA = PreservedAnalyses::allInSet<AllAnalysesOn<Function>>();
1114 PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
1115 AM.invalidate(*MergedC, PA);
1119 // If we formed a cycle by creating this call, we need to update more data
1120 // structures.
1121 if (FormedCycle) {
1122 C = &TargetC;
1123 assert(G.lookupSCC(N) == C && "Failed to update current SCC!");
1125 // If one of the invalidated SCCs had a cached proxy to a function
1126 // analysis manager, we need to create a proxy in the new current SCC as
1127 // the invalidated SCCs had their functions moved.
1128 if (HasFunctionAnalysisProxy)
1129 AM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, G).updateFAM(FAM);
1131 // Any analyses cached for this SCC are no longer precise as the shape
1132 // has changed by introducing this cycle. However, we have taken care to
1133 // update the proxies so it remains valide.
1134 auto PA = PreservedAnalyses::allInSet<AllAnalysesOn<Function>>();
1135 PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
1136 AM.invalidate(*C, PA);
1138 auto NewSCCIndex = RC->find(*C) - RC->begin();
1139 // If we have actually moved an SCC to be topologically "below" the current
1140 // one due to merging, we will need to revisit the current SCC after
1141 // visiting those moved SCCs.
1143 // It is critical that we *do not* revisit the current SCC unless we
1144 // actually move SCCs in the process of merging because otherwise we may
1145 // form a cycle where an SCC is split apart, merged, split, merged and so
1146 // on infinitely.
1147 if (InitialSCCIndex < NewSCCIndex) {
1148 // Put our current SCC back onto the worklist as we'll visit other SCCs
1149 // that are now definitively ordered prior to the current one in the
1150 // post-order sequence, and may end up observing more precise context to
1151 // optimize the current SCC.
1152 UR.CWorklist.insert(C);
1153 LLVM_DEBUG(dbgs() << "Enqueuing the existing SCC in the worklist: " << *C
1154 << "\n");
1155 // Enqueue in reverse order as we pop off the back of the worklist.
1156 for (SCC &MovedC : llvm::reverse(make_range(RC->begin() + InitialSCCIndex,
1157 RC->begin() + NewSCCIndex))) {
1158 UR.CWorklist.insert(&MovedC);
1159 LLVM_DEBUG(dbgs() << "Enqueuing a newly earlier in post-order SCC: "
1160 << MovedC << "\n");
1165 assert(!UR.InvalidatedSCCs.count(C) && "Invalidated the current SCC!");
1166 assert(&C->getOuterRefSCC() == RC && "Current SCC not in current RefSCC!");
1168 // Record the current SCC for higher layers of the CGSCC pass manager now that
1169 // all the updates have been applied.
1170 if (C != &InitialC)
1171 UR.UpdatedC = C;
1173 return *C;
1176 LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
1177 LazyCallGraph &G, LazyCallGraph::SCC &InitialC, LazyCallGraph::Node &N,
1178 CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR,
1179 FunctionAnalysisManager &FAM) {
1180 return updateCGAndAnalysisManagerForPass(G, InitialC, N, AM, UR, FAM,
1181 /* FunctionPass */ true);
1183 LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForCGSCCPass(
1184 LazyCallGraph &G, LazyCallGraph::SCC &InitialC, LazyCallGraph::Node &N,
1185 CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR,
1186 FunctionAnalysisManager &FAM) {
1187 return updateCGAndAnalysisManagerForPass(G, InitialC, N, AM, UR, FAM,
1188 /* FunctionPass */ false);