1 //===- Parsing, selection, and construction of pass pipelines -------------===//
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 /// \file
10 ///
11 /// This file provides the implementation of the PassBuilder based on our
12 /// static pass registry as well as related functionality. It also provides
13 /// helpers to aid in analyzing, debugging, and testing passes and pass
14 /// pipelines.
15 ///
16 //===----------------------------------------------------------------------===//
17 
18 #include "llvm/Passes/PassBuilder.h"
19 #include "llvm/ADT/StringSwitch.h"
20 #include "llvm/Analysis/AliasAnalysis.h"
21 #include "llvm/Analysis/AliasAnalysisEvaluator.h"
22 #include "llvm/Analysis/AssumptionCache.h"
23 #include "llvm/Analysis/BasicAliasAnalysis.h"
24 #include "llvm/Analysis/BlockFrequencyInfo.h"
25 #include "llvm/Analysis/BranchProbabilityInfo.h"
26 #include "llvm/Analysis/CFGPrinter.h"
27 #include "llvm/Analysis/CFLAndersAliasAnalysis.h"
28 #include "llvm/Analysis/CFLSteensAliasAnalysis.h"
29 #include "llvm/Analysis/CGSCCPassManager.h"
30 #include "llvm/Analysis/CallGraph.h"
31 #include "llvm/Analysis/DemandedBits.h"
32 #include "llvm/Analysis/DependenceAnalysis.h"
33 #include "llvm/Analysis/DominanceFrontier.h"
34 #include "llvm/Analysis/GlobalsModRef.h"
35 #include "llvm/Analysis/IVUsers.h"
36 #include "llvm/Analysis/LazyCallGraph.h"
37 #include "llvm/Analysis/LazyValueInfo.h"
38 #include "llvm/Analysis/LoopAccessAnalysis.h"
39 #include "llvm/Analysis/LoopInfo.h"
40 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
41 #include "llvm/Analysis/MemorySSA.h"
42 #include "llvm/Analysis/ModuleSummaryAnalysis.h"
43 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
44 #include "llvm/Analysis/PhiValues.h"
45 #include "llvm/Analysis/PostDominators.h"
46 #include "llvm/Analysis/ProfileSummaryInfo.h"
47 #include "llvm/Analysis/RegionInfo.h"
48 #include "llvm/Analysis/ScalarEvolution.h"
49 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
50 #include "llvm/Analysis/ScopedNoAliasAA.h"
51 #include "llvm/Analysis/StackSafetyAnalysis.h"
52 #include "llvm/Analysis/TargetLibraryInfo.h"
53 #include "llvm/Analysis/TargetTransformInfo.h"
54 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
55 #include "llvm/CodeGen/PreISelIntrinsicLowering.h"
56 #include "llvm/CodeGen/UnreachableBlockElim.h"
57 #include "llvm/IR/Dominators.h"
58 #include "llvm/IR/IRPrintingPasses.h"
59 #include "llvm/IR/PassManager.h"
60 #include "llvm/IR/Verifier.h"
61 #include "llvm/Support/Debug.h"
62 #include "llvm/Support/FormatVariadic.h"
63 #include "llvm/Support/Regex.h"
64 #include "llvm/Target/TargetMachine.h"
65 #include "llvm/Transforms/AggressiveInstCombine/AggressiveInstCombine.h"
66 #include "llvm/Transforms/IPO/AlwaysInliner.h"
67 #include "llvm/Transforms/IPO/ArgumentPromotion.h"
68 #include "llvm/Transforms/IPO/CalledValuePropagation.h"
69 #include "llvm/Transforms/IPO/ConstantMerge.h"
70 #include "llvm/Transforms/IPO/CrossDSOCFI.h"
71 #include "llvm/Transforms/IPO/DeadArgumentElimination.h"
72 #include "llvm/Transforms/IPO/ElimAvailExtern.h"
73 #include "llvm/Transforms/IPO/ForceFunctionAttrs.h"
74 #include "llvm/Transforms/IPO/FunctionAttrs.h"
75 #include "llvm/Transforms/IPO/FunctionImport.h"
76 #include "llvm/Transforms/IPO/GlobalDCE.h"
77 #include "llvm/Transforms/IPO/GlobalOpt.h"
78 #include "llvm/Transforms/IPO/GlobalSplit.h"
79 #include "llvm/Transforms/IPO/HotColdSplitting.h"
80 #include "llvm/Transforms/IPO/InferFunctionAttrs.h"
81 #include "llvm/Transforms/IPO/Inliner.h"
82 #include "llvm/Transforms/IPO/Internalize.h"
83 #include "llvm/Transforms/IPO/LowerTypeTests.h"
84 #include "llvm/Transforms/IPO/PartialInlining.h"
85 #include "llvm/Transforms/IPO/SCCP.h"
86 #include "llvm/Transforms/IPO/SampleProfile.h"
87 #include "llvm/Transforms/IPO/StripDeadPrototypes.h"
88 #include "llvm/Transforms/IPO/SyntheticCountsPropagation.h"
89 #include "llvm/Transforms/IPO/WholeProgramDevirt.h"
90 #include "llvm/Transforms/InstCombine/InstCombine.h"
91 #include "llvm/Transforms/Instrumentation/BoundsChecking.h"
92 #include "llvm/Transforms/Instrumentation/CGProfile.h"
93 #include "llvm/Transforms/Instrumentation/ControlHeightReduction.h"
94 #include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
95 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
96 #include "llvm/Transforms/Instrumentation/PGOInstrumentation.h"
97 #include "llvm/Transforms/Scalar/ADCE.h"
98 #include "llvm/Transforms/Scalar/AlignmentFromAssumptions.h"
99 #include "llvm/Transforms/Scalar/BDCE.h"
100 #include "llvm/Transforms/Scalar/CallSiteSplitting.h"
101 #include "llvm/Transforms/Scalar/ConstantHoisting.h"
102 #include "llvm/Transforms/Scalar/CorrelatedValuePropagation.h"
103 #include "llvm/Transforms/Scalar/DCE.h"
104 #include "llvm/Transforms/Scalar/DeadStoreElimination.h"
105 #include "llvm/Transforms/Scalar/DivRemPairs.h"
106 #include "llvm/Transforms/Scalar/EarlyCSE.h"
107 #include "llvm/Transforms/Scalar/Float2Int.h"
108 #include "llvm/Transforms/Scalar/GVN.h"
109 #include "llvm/Transforms/Scalar/GuardWidening.h"
110 #include "llvm/Transforms/Scalar/IVUsersPrinter.h"
111 #include "llvm/Transforms/Scalar/IndVarSimplify.h"
112 #include "llvm/Transforms/Scalar/InductiveRangeCheckElimination.h"
113 #include "llvm/Transforms/Scalar/InstSimplifyPass.h"
114 #include "llvm/Transforms/Scalar/JumpThreading.h"
115 #include "llvm/Transforms/Scalar/LICM.h"
116 #include "llvm/Transforms/Scalar/LoopAccessAnalysisPrinter.h"
117 #include "llvm/Transforms/Scalar/LoopDataPrefetch.h"
118 #include "llvm/Transforms/Scalar/LoopDeletion.h"
119 #include "llvm/Transforms/Scalar/LoopDistribute.h"
120 #include "llvm/Transforms/Scalar/LoopIdiomRecognize.h"
121 #include "llvm/Transforms/Scalar/LoopInstSimplify.h"
122 #include "llvm/Transforms/Scalar/LoopLoadElimination.h"
123 #include "llvm/Transforms/Scalar/LoopPassManager.h"
124 #include "llvm/Transforms/Scalar/LoopPredication.h"
125 #include "llvm/Transforms/Scalar/LoopRotation.h"
126 #include "llvm/Transforms/Scalar/LoopSimplifyCFG.h"
127 #include "llvm/Transforms/Scalar/LoopSink.h"
128 #include "llvm/Transforms/Scalar/LoopStrengthReduce.h"
129 #include "llvm/Transforms/Scalar/LoopUnrollAndJamPass.h"
130 #include "llvm/Transforms/Scalar/LoopUnrollPass.h"
131 #include "llvm/Transforms/Scalar/LowerAtomic.h"
132 #include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
133 #include "llvm/Transforms/Scalar/LowerGuardIntrinsic.h"
134 #include "llvm/Transforms/Scalar/MemCpyOptimizer.h"
135 #include "llvm/Transforms/Scalar/MergedLoadStoreMotion.h"
136 #include "llvm/Transforms/Scalar/NaryReassociate.h"
137 #include "llvm/Transforms/Scalar/NewGVN.h"
138 #include "llvm/Transforms/Scalar/PartiallyInlineLibCalls.h"
139 #include "llvm/Transforms/Scalar/Reassociate.h"
140 #include "llvm/Transforms/Scalar/RewriteStatepointsForGC.h"
141 #include "llvm/Transforms/Scalar/SCCP.h"
142 #include "llvm/Transforms/Scalar/SROA.h"
143 #include "llvm/Transforms/Scalar/Scalarizer.h"
144 #include "llvm/Transforms/Scalar/SimpleLoopUnswitch.h"
145 #include "llvm/Transforms/Scalar/SimplifyCFG.h"
146 #include "llvm/Transforms/Scalar/Sink.h"
147 #include "llvm/Transforms/Scalar/SpeculateAroundPHIs.h"
148 #include "llvm/Transforms/Scalar/SpeculativeExecution.h"
149 #include "llvm/Transforms/Scalar/TailRecursionElimination.h"
150 #include "llvm/Transforms/Utils/AddDiscriminators.h"
151 #include "llvm/Transforms/Utils/BreakCriticalEdges.h"
152 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
153 #include "llvm/Transforms/Utils/LCSSA.h"
154 #include "llvm/Transforms/Utils/LibCallsShrinkWrap.h"
155 #include "llvm/Transforms/Utils/LoopSimplify.h"
156 #include "llvm/Transforms/Utils/LowerInvoke.h"
157 #include "llvm/Transforms/Utils/Mem2Reg.h"
158 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
159 #include "llvm/Transforms/Utils/SymbolRewriter.h"
160 #include "llvm/Transforms/Vectorize/LoopVectorize.h"
161 #include "llvm/Transforms/Vectorize/SLPVectorizer.h"
162 
163 using namespace llvm;
164 
165 static cl::opt<unsigned> MaxDevirtIterations("pm-max-devirt-iterations",
166                                              cl::ReallyHidden, cl::init(4));
167 static cl::opt<bool>
168     RunPartialInlining("enable-npm-partial-inlining", cl::init(false),
169                        cl::Hidden, cl::ZeroOrMore,
170                        cl::desc("Run Partial inlinining pass"));
171 
172 static cl::opt<bool>
173     RunNewGVN("enable-npm-newgvn", cl::init(false),
174               cl::Hidden, cl::ZeroOrMore,
175               cl::desc("Run NewGVN instead of GVN"));
176 
177 static cl::opt<bool> EnableEarlyCSEMemSSA(
178     "enable-npm-earlycse-memssa", cl::init(true), cl::Hidden,
179     cl::desc("Enable the EarlyCSE w/ MemorySSA pass for the new PM (default = on)"));
180 
181 static cl::opt<bool> EnableGVNHoist(
182     "enable-npm-gvn-hoist", cl::init(false), cl::Hidden,
183     cl::desc("Enable the GVN hoisting pass for the new PM (default = off)"));
184 
185 static cl::opt<bool> EnableGVNSink(
186     "enable-npm-gvn-sink", cl::init(false), cl::Hidden,
187     cl::desc("Enable the GVN hoisting pass for the new PM (default = off)"));
188 
189 static cl::opt<bool> EnableUnrollAndJam(
190     "enable-npm-unroll-and-jam", cl::init(false), cl::Hidden,
191     cl::desc("Enable the Unroll and Jam pass for the new PM (default = off)"));
192 
193 static cl::opt<bool> EnableSyntheticCounts(
194     "enable-npm-synthetic-counts", cl::init(false), cl::Hidden, cl::ZeroOrMore,
195     cl::desc("Run synthetic function entry count generation "
196              "pass"));
197 
198 static Regex DefaultAliasRegex(
199     "^(default|thinlto-pre-link|thinlto|lto-pre-link|lto)<(O[0123sz])>$");
200 
201 static cl::opt<bool>
202     EnableCHR("enable-chr-npm", cl::init(true), cl::Hidden,
203               cl::desc("Enable control height reduction optimization (CHR)"));
204 
205 extern cl::opt<bool> EnableHotColdSplit;
206 
207 static bool isOptimizingForSize(PassBuilder::OptimizationLevel Level) {
208   switch (Level) {
209   case PassBuilder::O0:
210   case PassBuilder::O1:
211   case PassBuilder::O2:
212   case PassBuilder::O3:
213     return false;
214 
215   case PassBuilder::Os:
216   case PassBuilder::Oz:
217     return true;
218   }
219   llvm_unreachable("Invalid optimization level!");
220 }
221 
222 namespace {
223 
224 /// No-op module pass which does nothing.
225 struct NoOpModulePass {
226   PreservedAnalyses run(Module &M, ModuleAnalysisManager &) {
227     return PreservedAnalyses::all();
228   }
229   static StringRef name() { return "NoOpModulePass"; }
230 };
231 
232 /// No-op module analysis.
233 class NoOpModuleAnalysis : public AnalysisInfoMixin<NoOpModuleAnalysis> {
234   friend AnalysisInfoMixin<NoOpModuleAnalysis>;
235   static AnalysisKey Key;
236 
237 public:
238   struct Result {};
239   Result run(Module &, ModuleAnalysisManager &) { return Result(); }
240   static StringRef name() { return "NoOpModuleAnalysis"; }
241 };
242 
243 /// No-op CGSCC pass which does nothing.
244 struct NoOpCGSCCPass {
245   PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &,
246                         LazyCallGraph &, CGSCCUpdateResult &UR) {
247     return PreservedAnalyses::all();
248   }
249   static StringRef name() { return "NoOpCGSCCPass"; }
250 };
251 
252 /// No-op CGSCC analysis.
253 class NoOpCGSCCAnalysis : public AnalysisInfoMixin<NoOpCGSCCAnalysis> {
254   friend AnalysisInfoMixin<NoOpCGSCCAnalysis>;
255   static AnalysisKey Key;
256 
257 public:
258   struct Result {};
259   Result run(LazyCallGraph::SCC &, CGSCCAnalysisManager &, LazyCallGraph &G) {
260     return Result();
261   }
262   static StringRef name() { return "NoOpCGSCCAnalysis"; }
263 };
264 
265 /// No-op function pass which does nothing.
266 struct NoOpFunctionPass {
267   PreservedAnalyses run(Function &F, FunctionAnalysisManager &) {
268     return PreservedAnalyses::all();
269   }
270   static StringRef name() { return "NoOpFunctionPass"; }
271 };
272 
273 /// No-op function analysis.
274 class NoOpFunctionAnalysis : public AnalysisInfoMixin<NoOpFunctionAnalysis> {
275   friend AnalysisInfoMixin<NoOpFunctionAnalysis>;
276   static AnalysisKey Key;
277 
278 public:
279   struct Result {};
280   Result run(Function &, FunctionAnalysisManager &) { return Result(); }
281   static StringRef name() { return "NoOpFunctionAnalysis"; }
282 };
283 
284 /// No-op loop pass which does nothing.
285 struct NoOpLoopPass {
286   PreservedAnalyses run(Loop &L, LoopAnalysisManager &,
287                         LoopStandardAnalysisResults &, LPMUpdater &) {
288     return PreservedAnalyses::all();
289   }
290   static StringRef name() { return "NoOpLoopPass"; }
291 };
292 
293 /// No-op loop analysis.
294 class NoOpLoopAnalysis : public AnalysisInfoMixin<NoOpLoopAnalysis> {
295   friend AnalysisInfoMixin<NoOpLoopAnalysis>;
296   static AnalysisKey Key;
297 
298 public:
299   struct Result {};
300   Result run(Loop &, LoopAnalysisManager &, LoopStandardAnalysisResults &) {
301     return Result();
302   }
303   static StringRef name() { return "NoOpLoopAnalysis"; }
304 };
305 
306 AnalysisKey NoOpModuleAnalysis::Key;
307 AnalysisKey NoOpCGSCCAnalysis::Key;
308 AnalysisKey NoOpFunctionAnalysis::Key;
309 AnalysisKey NoOpLoopAnalysis::Key;
310 
311 } // End anonymous namespace.
312 
313 void PassBuilder::invokePeepholeEPCallbacks(
314     FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
315   for (auto &C : PeepholeEPCallbacks)
316     C(FPM, Level);
317 }
318 
319 void PassBuilder::registerModuleAnalyses(ModuleAnalysisManager &MAM) {
320 #define MODULE_ANALYSIS(NAME, CREATE_PASS)                                     \
321   MAM.registerPass([&] { return CREATE_PASS; });
322 #include "PassRegistry.def"
323 
324   for (auto &C : ModuleAnalysisRegistrationCallbacks)
325     C(MAM);
326 }
327 
328 void PassBuilder::registerCGSCCAnalyses(CGSCCAnalysisManager &CGAM) {
329 #define CGSCC_ANALYSIS(NAME, CREATE_PASS)                                      \
330   CGAM.registerPass([&] { return CREATE_PASS; });
331 #include "PassRegistry.def"
332 
333   for (auto &C : CGSCCAnalysisRegistrationCallbacks)
334     C(CGAM);
335 }
336 
337 void PassBuilder::registerFunctionAnalyses(FunctionAnalysisManager &FAM) {
338 #define FUNCTION_ANALYSIS(NAME, CREATE_PASS)                                   \
339   FAM.registerPass([&] { return CREATE_PASS; });
340 #include "PassRegistry.def"
341 
342   for (auto &C : FunctionAnalysisRegistrationCallbacks)
343     C(FAM);
344 }
345 
346 void PassBuilder::registerLoopAnalyses(LoopAnalysisManager &LAM) {
347 #define LOOP_ANALYSIS(NAME, CREATE_PASS)                                       \
348   LAM.registerPass([&] { return CREATE_PASS; });
349 #include "PassRegistry.def"
350 
351   for (auto &C : LoopAnalysisRegistrationCallbacks)
352     C(LAM);
353 }
354 
355 FunctionPassManager
356 PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
357                                                  ThinLTOPhase Phase,
358                                                  bool DebugLogging) {
359   assert(Level != O0 && "Must request optimizations!");
360   FunctionPassManager FPM(DebugLogging);
361 
362   // Form SSA out of local memory accesses after breaking apart aggregates into
363   // scalars.
364   FPM.addPass(SROA());
365 
366   // Catch trivial redundancies
367   FPM.addPass(EarlyCSEPass(EnableEarlyCSEMemSSA));
368 
369   // Hoisting of scalars and load expressions.
370   if (EnableGVNHoist)
371     FPM.addPass(GVNHoistPass());
372 
373   // Global value numbering based sinking.
374   if (EnableGVNSink) {
375     FPM.addPass(GVNSinkPass());
376     FPM.addPass(SimplifyCFGPass());
377   }
378 
379   // Speculative execution if the target has divergent branches; otherwise nop.
380   FPM.addPass(SpeculativeExecutionPass());
381 
382   // Optimize based on known information about branches, and cleanup afterward.
383   FPM.addPass(JumpThreadingPass());
384   FPM.addPass(CorrelatedValuePropagationPass());
385   FPM.addPass(SimplifyCFGPass());
386   if (Level == O3)
387     FPM.addPass(AggressiveInstCombinePass());
388   FPM.addPass(InstCombinePass());
389 
390   if (!isOptimizingForSize(Level))
391     FPM.addPass(LibCallsShrinkWrapPass());
392 
393   invokePeepholeEPCallbacks(FPM, Level);
394 
395   // For PGO use pipeline, try to optimize memory intrinsics such as memcpy
396   // using the size value profile. Don't perform this when optimizing for size.
397   if (PGOOpt && !PGOOpt->ProfileUseFile.empty() &&
398       !isOptimizingForSize(Level))
399     FPM.addPass(PGOMemOPSizeOpt());
400 
401   FPM.addPass(TailCallElimPass());
402   FPM.addPass(SimplifyCFGPass());
403 
404   // Form canonically associated expression trees, and simplify the trees using
405   // basic mathematical properties. For example, this will form (nearly)
406   // minimal multiplication trees.
407   FPM.addPass(ReassociatePass());
408 
409   // Add the primary loop simplification pipeline.
410   // FIXME: Currently this is split into two loop pass pipelines because we run
411   // some function passes in between them. These can and should be removed
412   // and/or replaced by scheduling the loop pass equivalents in the correct
413   // positions. But those equivalent passes aren't powerful enough yet.
414   // Specifically, `SimplifyCFGPass` and `InstCombinePass` are currently still
415   // used. We have `LoopSimplifyCFGPass` which isn't yet powerful enough yet to
416   // fully replace `SimplifyCFGPass`, and the closest to the other we have is
417   // `LoopInstSimplify`.
418   LoopPassManager LPM1(DebugLogging), LPM2(DebugLogging);
419 
420   // Simplify the loop body. We do this initially to clean up after other loop
421   // passes run, either when iterating on a loop or on inner loops with
422   // implications on the outer loop.
423   LPM1.addPass(LoopInstSimplifyPass());
424   LPM1.addPass(LoopSimplifyCFGPass());
425 
426   // Rotate Loop - disable header duplication at -Oz
427   LPM1.addPass(LoopRotatePass(Level != Oz));
428   LPM1.addPass(LICMPass());
429   LPM1.addPass(SimpleLoopUnswitchPass());
430   LPM2.addPass(IndVarSimplifyPass());
431   LPM2.addPass(LoopIdiomRecognizePass());
432 
433   for (auto &C : LateLoopOptimizationsEPCallbacks)
434     C(LPM2, Level);
435 
436   LPM2.addPass(LoopDeletionPass());
437   // Do not enable unrolling in PreLinkThinLTO phase during sample PGO
438   // because it changes IR to makes profile annotation in back compile
439   // inaccurate.
440   if (Phase != ThinLTOPhase::PreLink ||
441       !PGOOpt || PGOOpt->SampleProfileFile.empty())
442     LPM2.addPass(LoopFullUnrollPass(Level));
443 
444   for (auto &C : LoopOptimizerEndEPCallbacks)
445     C(LPM2, Level);
446 
447   // We provide the opt remark emitter pass for LICM to use. We only need to do
448   // this once as it is immutable.
449   FPM.addPass(RequireAnalysisPass<OptimizationRemarkEmitterAnalysis, Function>());
450   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM1), DebugLogging));
451   FPM.addPass(SimplifyCFGPass());
452   FPM.addPass(InstCombinePass());
453   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM2), DebugLogging));
454 
455   // Eliminate redundancies.
456   if (Level != O1) {
457     // These passes add substantial compile time so skip them at O1.
458     FPM.addPass(MergedLoadStoreMotionPass());
459     if (RunNewGVN)
460       FPM.addPass(NewGVNPass());
461     else
462       FPM.addPass(GVN());
463   }
464 
465   // Specially optimize memory movement as it doesn't look like dataflow in SSA.
466   FPM.addPass(MemCpyOptPass());
467 
468   // Sparse conditional constant propagation.
469   // FIXME: It isn't clear why we do this *after* loop passes rather than
470   // before...
471   FPM.addPass(SCCPPass());
472 
473   // Delete dead bit computations (instcombine runs after to fold away the dead
474   // computations, and then ADCE will run later to exploit any new DCE
475   // opportunities that creates).
476   FPM.addPass(BDCEPass());
477 
478   // Run instcombine after redundancy and dead bit elimination to exploit
479   // opportunities opened up by them.
480   FPM.addPass(InstCombinePass());
481   invokePeepholeEPCallbacks(FPM, Level);
482 
483   // Re-consider control flow based optimizations after redundancy elimination,
484   // redo DCE, etc.
485   FPM.addPass(JumpThreadingPass());
486   FPM.addPass(CorrelatedValuePropagationPass());
487   FPM.addPass(DSEPass());
488   FPM.addPass(createFunctionToLoopPassAdaptor(LICMPass(), DebugLogging));
489 
490   for (auto &C : ScalarOptimizerLateEPCallbacks)
491     C(FPM, Level);
492 
493   // Finally, do an expensive DCE pass to catch all the dead code exposed by
494   // the simplifications and basic cleanup after all the simplifications.
495   FPM.addPass(ADCEPass());
496   FPM.addPass(SimplifyCFGPass());
497   FPM.addPass(InstCombinePass());
498   invokePeepholeEPCallbacks(FPM, Level);
499 
500   if (EnableCHR && Level == O3 && PGOOpt &&
501       (!PGOOpt->ProfileUseFile.empty() || !PGOOpt->SampleProfileFile.empty()))
502     FPM.addPass(ControlHeightReductionPass());
503 
504   return FPM;
505 }
506 
507 void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM, bool DebugLogging,
508                                     PassBuilder::OptimizationLevel Level,
509                                     bool RunProfileGen,
510                                     std::string ProfileGenFile,
511                                     std::string ProfileUseFile,
512                                     std::string ProfileRemappingFile) {
513   // Generally running simplification passes and the inliner with an high
514   // threshold results in smaller executables, but there may be cases where
515   // the size grows, so let's be conservative here and skip this simplification
516   // at -Os/Oz.
517   if (!isOptimizingForSize(Level)) {
518     InlineParams IP;
519 
520     // In the old pass manager, this is a cl::opt. Should still this be one?
521     IP.DefaultThreshold = 75;
522 
523     // FIXME: The hint threshold has the same value used by the regular inliner.
524     // This should probably be lowered after performance testing.
525     // FIXME: this comment is cargo culted from the old pass manager, revisit).
526     IP.HintThreshold = 325;
527 
528     CGSCCPassManager CGPipeline(DebugLogging);
529 
530     CGPipeline.addPass(InlinerPass(IP));
531 
532     FunctionPassManager FPM;
533     FPM.addPass(SROA());
534     FPM.addPass(EarlyCSEPass());    // Catch trivial redundancies.
535     FPM.addPass(SimplifyCFGPass()); // Merge & remove basic blocks.
536     FPM.addPass(InstCombinePass()); // Combine silly sequences.
537     invokePeepholeEPCallbacks(FPM, Level);
538 
539     CGPipeline.addPass(createCGSCCToFunctionPassAdaptor(std::move(FPM)));
540 
541     MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPipeline)));
542   }
543 
544   // Delete anything that is now dead to make sure that we don't instrument
545   // dead code. Instrumentation can end up keeping dead code around and
546   // dramatically increase code size.
547   MPM.addPass(GlobalDCEPass());
548 
549   if (RunProfileGen) {
550     MPM.addPass(PGOInstrumentationGen());
551 
552     FunctionPassManager FPM;
553     FPM.addPass(
554         createFunctionToLoopPassAdaptor(LoopRotatePass(), DebugLogging));
555     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
556 
557     // Add the profile lowering pass.
558     InstrProfOptions Options;
559     if (!ProfileGenFile.empty())
560       Options.InstrProfileOutput = ProfileGenFile;
561     Options.DoCounterPromotion = true;
562     MPM.addPass(InstrProfiling(Options));
563   }
564 
565   if (!ProfileUseFile.empty())
566     MPM.addPass(PGOInstrumentationUse(ProfileUseFile, ProfileRemappingFile));
567 }
568 
569 static InlineParams
570 getInlineParamsFromOptLevel(PassBuilder::OptimizationLevel Level) {
571   auto O3 = PassBuilder::O3;
572   unsigned OptLevel = Level > O3 ? 2 : Level;
573   unsigned SizeLevel = Level > O3 ? Level - O3 : 0;
574   return getInlineParams(OptLevel, SizeLevel);
575 }
576 
577 ModulePassManager
578 PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
579                                                ThinLTOPhase Phase,
580                                                bool DebugLogging) {
581   ModulePassManager MPM(DebugLogging);
582 
583   // Do basic inference of function attributes from known properties of system
584   // libraries and other oracles.
585   MPM.addPass(InferFunctionAttrsPass());
586 
587   // Create an early function pass manager to cleanup the output of the
588   // frontend.
589   FunctionPassManager EarlyFPM(DebugLogging);
590   EarlyFPM.addPass(SimplifyCFGPass());
591   EarlyFPM.addPass(SROA());
592   EarlyFPM.addPass(EarlyCSEPass());
593   EarlyFPM.addPass(LowerExpectIntrinsicPass());
594   if (Level == O3)
595     EarlyFPM.addPass(CallSiteSplittingPass());
596 
597   // In SamplePGO ThinLTO backend, we need instcombine before profile annotation
598   // to convert bitcast to direct calls so that they can be inlined during the
599   // profile annotation prepration step.
600   // More details about SamplePGO design can be found in:
601   // https://research.google.com/pubs/pub45290.html
602   // FIXME: revisit how SampleProfileLoad/Inliner/ICP is structured.
603   if (PGOOpt && !PGOOpt->SampleProfileFile.empty() &&
604       Phase == ThinLTOPhase::PostLink)
605     EarlyFPM.addPass(InstCombinePass());
606   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(EarlyFPM)));
607 
608   if (PGOOpt && !PGOOpt->SampleProfileFile.empty()) {
609     // Annotate sample profile right after early FPM to ensure freshness of
610     // the debug info.
611     MPM.addPass(SampleProfileLoaderPass(PGOOpt->SampleProfileFile,
612                                         PGOOpt->ProfileRemappingFile,
613                                         Phase == ThinLTOPhase::PreLink));
614     // Do not invoke ICP in the ThinLTOPrelink phase as it makes it hard
615     // for the profile annotation to be accurate in the ThinLTO backend.
616     if (Phase != ThinLTOPhase::PreLink)
617       // We perform early indirect call promotion here, before globalopt.
618       // This is important for the ThinLTO backend phase because otherwise
619       // imported available_externally functions look unreferenced and are
620       // removed.
621       MPM.addPass(PGOIndirectCallPromotion(Phase == ThinLTOPhase::PostLink,
622                                            true));
623   }
624 
625   // Interprocedural constant propagation now that basic cleanup has occurred
626   // and prior to optimizing globals.
627   // FIXME: This position in the pipeline hasn't been carefully considered in
628   // years, it should be re-analyzed.
629   MPM.addPass(IPSCCPPass());
630 
631   // Attach metadata to indirect call sites indicating the set of functions
632   // they may target at run-time. This should follow IPSCCP.
633   MPM.addPass(CalledValuePropagationPass());
634 
635   // Optimize globals to try and fold them into constants.
636   MPM.addPass(GlobalOptPass());
637 
638   // Promote any localized globals to SSA registers.
639   // FIXME: Should this instead by a run of SROA?
640   // FIXME: We should probably run instcombine and simplify-cfg afterward to
641   // delete control flows that are dead once globals have been folded to
642   // constants.
643   MPM.addPass(createModuleToFunctionPassAdaptor(PromotePass()));
644 
645   // Remove any dead arguments exposed by cleanups and constand folding
646   // globals.
647   MPM.addPass(DeadArgumentEliminationPass());
648 
649   // Create a small function pass pipeline to cleanup after all the global
650   // optimizations.
651   FunctionPassManager GlobalCleanupPM(DebugLogging);
652   GlobalCleanupPM.addPass(InstCombinePass());
653   invokePeepholeEPCallbacks(GlobalCleanupPM, Level);
654 
655   GlobalCleanupPM.addPass(SimplifyCFGPass());
656   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(GlobalCleanupPM)));
657 
658   // Add all the requested passes for instrumentation PGO, if requested.
659   if (PGOOpt && Phase != ThinLTOPhase::PostLink &&
660       (!PGOOpt->ProfileGenFile.empty() || !PGOOpt->ProfileUseFile.empty())) {
661     addPGOInstrPasses(MPM, DebugLogging, Level, PGOOpt->RunProfileGen,
662                       PGOOpt->ProfileGenFile, PGOOpt->ProfileUseFile,
663                       PGOOpt->ProfileRemappingFile);
664     MPM.addPass(PGOIndirectCallPromotion(false, false));
665   }
666 
667   // Synthesize function entry counts for non-PGO compilation.
668   if (EnableSyntheticCounts && !PGOOpt)
669     MPM.addPass(SyntheticCountsPropagation());
670 
671   // Require the GlobalsAA analysis for the module so we can query it within
672   // the CGSCC pipeline.
673   MPM.addPass(RequireAnalysisPass<GlobalsAA, Module>());
674 
675   // Require the ProfileSummaryAnalysis for the module so we can query it within
676   // the inliner pass.
677   MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
678 
679   // Now begin the main postorder CGSCC pipeline.
680   // FIXME: The current CGSCC pipeline has its origins in the legacy pass
681   // manager and trying to emulate its precise behavior. Much of this doesn't
682   // make a lot of sense and we should revisit the core CGSCC structure.
683   CGSCCPassManager MainCGPipeline(DebugLogging);
684 
685   // Note: historically, the PruneEH pass was run first to deduce nounwind and
686   // generally clean up exception handling overhead. It isn't clear this is
687   // valuable as the inliner doesn't currently care whether it is inlining an
688   // invoke or a call.
689 
690   // Run the inliner first. The theory is that we are walking bottom-up and so
691   // the callees have already been fully optimized, and we want to inline them
692   // into the callers so that our optimizations can reflect that.
693   // For PreLinkThinLTO pass, we disable hot-caller heuristic for sample PGO
694   // because it makes profile annotation in the backend inaccurate.
695   InlineParams IP = getInlineParamsFromOptLevel(Level);
696   if (Phase == ThinLTOPhase::PreLink &&
697       PGOOpt && !PGOOpt->SampleProfileFile.empty())
698     IP.HotCallSiteThreshold = 0;
699   MainCGPipeline.addPass(InlinerPass(IP));
700 
701   // Now deduce any function attributes based in the current code.
702   MainCGPipeline.addPass(PostOrderFunctionAttrsPass());
703 
704   // When at O3 add argument promotion to the pass pipeline.
705   // FIXME: It isn't at all clear why this should be limited to O3.
706   if (Level == O3)
707     MainCGPipeline.addPass(ArgumentPromotionPass());
708 
709   // Lastly, add the core function simplification pipeline nested inside the
710   // CGSCC walk.
711   MainCGPipeline.addPass(createCGSCCToFunctionPassAdaptor(
712       buildFunctionSimplificationPipeline(Level, Phase, DebugLogging)));
713 
714   // We only want to do hot cold splitting once for ThinLTO, during the
715   // post-link ThinLTO.
716   if (EnableHotColdSplit && Phase != ThinLTOPhase::PreLink)
717     MPM.addPass(HotColdSplittingPass());
718 
719   for (auto &C : CGSCCOptimizerLateEPCallbacks)
720     C(MainCGPipeline, Level);
721 
722   // We wrap the CGSCC pipeline in a devirtualization repeater. This will try
723   // to detect when we devirtualize indirect calls and iterate the SCC passes
724   // in that case to try and catch knock-on inlining or function attrs
725   // opportunities. Then we add it to the module pipeline by walking the SCCs
726   // in postorder (or bottom-up).
727   MPM.addPass(
728       createModuleToPostOrderCGSCCPassAdaptor(createDevirtSCCRepeatedPass(
729           std::move(MainCGPipeline), MaxDevirtIterations)));
730 
731   return MPM;
732 }
733 
734 ModulePassManager
735 PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
736                                              bool DebugLogging) {
737   ModulePassManager MPM(DebugLogging);
738 
739   // Optimize globals now that the module is fully simplified.
740   MPM.addPass(GlobalOptPass());
741   MPM.addPass(GlobalDCEPass());
742 
743   // Run partial inlining pass to partially inline functions that have
744   // large bodies.
745   if (RunPartialInlining)
746     MPM.addPass(PartialInlinerPass());
747 
748   // Remove avail extern fns and globals definitions since we aren't compiling
749   // an object file for later LTO. For LTO we want to preserve these so they
750   // are eligible for inlining at link-time. Note if they are unreferenced they
751   // will be removed by GlobalDCE later, so this only impacts referenced
752   // available externally globals. Eventually they will be suppressed during
753   // codegen, but eliminating here enables more opportunity for GlobalDCE as it
754   // may make globals referenced by available external functions dead and saves
755   // running remaining passes on the eliminated functions.
756   MPM.addPass(EliminateAvailableExternallyPass());
757 
758   // Do RPO function attribute inference across the module to forward-propagate
759   // attributes where applicable.
760   // FIXME: Is this really an optimization rather than a canonicalization?
761   MPM.addPass(ReversePostOrderFunctionAttrsPass());
762 
763   // Re-require GloblasAA here prior to function passes. This is particularly
764   // useful as the above will have inlined, DCE'ed, and function-attr
765   // propagated everything. We should at this point have a reasonably minimal
766   // and richly annotated call graph. By computing aliasing and mod/ref
767   // information for all local globals here, the late loop passes and notably
768   // the vectorizer will be able to use them to help recognize vectorizable
769   // memory operations.
770   MPM.addPass(RequireAnalysisPass<GlobalsAA, Module>());
771 
772   FunctionPassManager OptimizePM(DebugLogging);
773   OptimizePM.addPass(Float2IntPass());
774   // FIXME: We need to run some loop optimizations to re-rotate loops after
775   // simplify-cfg and others undo their rotation.
776 
777   // Optimize the loop execution. These passes operate on entire loop nests
778   // rather than on each loop in an inside-out manner, and so they are actually
779   // function passes.
780 
781   for (auto &C : VectorizerStartEPCallbacks)
782     C(OptimizePM, Level);
783 
784   // First rotate loops that may have been un-rotated by prior passes.
785   OptimizePM.addPass(
786       createFunctionToLoopPassAdaptor(LoopRotatePass(), DebugLogging));
787 
788   // Distribute loops to allow partial vectorization.  I.e. isolate dependences
789   // into separate loop that would otherwise inhibit vectorization.  This is
790   // currently only performed for loops marked with the metadata
791   // llvm.loop.distribute=true or when -enable-loop-distribute is specified.
792   OptimizePM.addPass(LoopDistributePass());
793 
794   // Now run the core loop vectorizer.
795   OptimizePM.addPass(LoopVectorizePass());
796 
797   // Eliminate loads by forwarding stores from the previous iteration to loads
798   // of the current iteration.
799   OptimizePM.addPass(LoopLoadEliminationPass());
800 
801   // Cleanup after the loop optimization passes.
802   OptimizePM.addPass(InstCombinePass());
803 
804   // Now that we've formed fast to execute loop structures, we do further
805   // optimizations. These are run afterward as they might block doing complex
806   // analyses and transforms such as what are needed for loop vectorization.
807 
808   // Cleanup after loop vectorization, etc. Simplification passes like CVP and
809   // GVN, loop transforms, and others have already run, so it's now better to
810   // convert to more optimized IR using more aggressive simplify CFG options.
811   // The extra sinking transform can create larger basic blocks, so do this
812   // before SLP vectorization.
813   OptimizePM.addPass(SimplifyCFGPass(SimplifyCFGOptions().
814                                      forwardSwitchCondToPhi(true).
815                                      convertSwitchToLookupTable(true).
816                                      needCanonicalLoops(false).
817                                      sinkCommonInsts(true)));
818 
819   // Optimize parallel scalar instruction chains into SIMD instructions.
820   OptimizePM.addPass(SLPVectorizerPass());
821 
822   OptimizePM.addPass(InstCombinePass());
823 
824   // Unroll small loops to hide loop backedge latency and saturate any parallel
825   // execution resources of an out-of-order processor. We also then need to
826   // clean up redundancies and loop invariant code.
827   // FIXME: It would be really good to use a loop-integrated instruction
828   // combiner for cleanup here so that the unrolling and LICM can be pipelined
829   // across the loop nests.
830   // We do UnrollAndJam in a separate LPM to ensure it happens before unroll
831   if (EnableUnrollAndJam) {
832     OptimizePM.addPass(
833         createFunctionToLoopPassAdaptor(LoopUnrollAndJamPass(Level)));
834   }
835   OptimizePM.addPass(LoopUnrollPass(LoopUnrollOptions(Level)));
836   OptimizePM.addPass(InstCombinePass());
837   OptimizePM.addPass(RequireAnalysisPass<OptimizationRemarkEmitterAnalysis, Function>());
838   OptimizePM.addPass(createFunctionToLoopPassAdaptor(LICMPass(), DebugLogging));
839 
840   // Now that we've vectorized and unrolled loops, we may have more refined
841   // alignment information, try to re-derive it here.
842   OptimizePM.addPass(AlignmentFromAssumptionsPass());
843 
844   // LoopSink pass sinks instructions hoisted by LICM, which serves as a
845   // canonicalization pass that enables other optimizations. As a result,
846   // LoopSink pass needs to be a very late IR pass to avoid undoing LICM
847   // result too early.
848   OptimizePM.addPass(LoopSinkPass());
849 
850   // And finally clean up LCSSA form before generating code.
851   OptimizePM.addPass(InstSimplifyPass());
852 
853   // This hoists/decomposes div/rem ops. It should run after other sink/hoist
854   // passes to avoid re-sinking, but before SimplifyCFG because it can allow
855   // flattening of blocks.
856   OptimizePM.addPass(DivRemPairsPass());
857 
858   // LoopSink (and other loop passes since the last simplifyCFG) might have
859   // resulted in single-entry-single-exit or empty blocks. Clean up the CFG.
860   OptimizePM.addPass(SimplifyCFGPass());
861 
862   // Optimize PHIs by speculating around them when profitable. Note that this
863   // pass needs to be run after any PRE or similar pass as it is essentially
864   // inserting redudnancies into the progrem. This even includes SimplifyCFG.
865   OptimizePM.addPass(SpeculateAroundPHIsPass());
866 
867   for (auto &C : OptimizerLastEPCallbacks)
868     C(OptimizePM, Level);
869 
870   // Add the core optimizing pipeline.
871   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(OptimizePM)));
872 
873   MPM.addPass(CGProfilePass());
874 
875   // Now we need to do some global optimization transforms.
876   // FIXME: It would seem like these should come first in the optimization
877   // pipeline and maybe be the bottom of the canonicalization pipeline? Weird
878   // ordering here.
879   MPM.addPass(GlobalDCEPass());
880   MPM.addPass(ConstantMergePass());
881 
882   return MPM;
883 }
884 
885 ModulePassManager
886 PassBuilder::buildPerModuleDefaultPipeline(OptimizationLevel Level,
887                                            bool DebugLogging) {
888   assert(Level != O0 && "Must request optimizations for the default pipeline!");
889 
890   ModulePassManager MPM(DebugLogging);
891 
892   // Force any function attributes we want the rest of the pipeline to observe.
893   MPM.addPass(ForceFunctionAttrsPass());
894 
895   // Apply module pipeline start EP callback.
896   for (auto &C : PipelineStartEPCallbacks)
897     C(MPM);
898 
899   if (PGOOpt && PGOOpt->SamplePGOSupport)
900     MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
901 
902   // Add the core simplification pipeline.
903   MPM.addPass(buildModuleSimplificationPipeline(Level, ThinLTOPhase::None,
904                                                 DebugLogging));
905 
906   // Now add the optimization pipeline.
907   MPM.addPass(buildModuleOptimizationPipeline(Level, DebugLogging));
908 
909   return MPM;
910 }
911 
912 ModulePassManager
913 PassBuilder::buildThinLTOPreLinkDefaultPipeline(OptimizationLevel Level,
914                                                 bool DebugLogging) {
915   assert(Level != O0 && "Must request optimizations for the default pipeline!");
916 
917   ModulePassManager MPM(DebugLogging);
918 
919   // Force any function attributes we want the rest of the pipeline to observe.
920   MPM.addPass(ForceFunctionAttrsPass());
921 
922   if (PGOOpt && PGOOpt->SamplePGOSupport)
923     MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
924 
925   // Apply module pipeline start EP callback.
926   for (auto &C : PipelineStartEPCallbacks)
927     C(MPM);
928 
929   // If we are planning to perform ThinLTO later, we don't bloat the code with
930   // unrolling/vectorization/... now. Just simplify the module as much as we
931   // can.
932   MPM.addPass(buildModuleSimplificationPipeline(Level, ThinLTOPhase::PreLink,
933                                                 DebugLogging));
934 
935   // Run partial inlining pass to partially inline functions that have
936   // large bodies.
937   // FIXME: It isn't clear whether this is really the right place to run this
938   // in ThinLTO. Because there is another canonicalization and simplification
939   // phase that will run after the thin link, running this here ends up with
940   // less information than will be available later and it may grow functions in
941   // ways that aren't beneficial.
942   if (RunPartialInlining)
943     MPM.addPass(PartialInlinerPass());
944 
945   // Reduce the size of the IR as much as possible.
946   MPM.addPass(GlobalOptPass());
947 
948   return MPM;
949 }
950 
951 ModulePassManager PassBuilder::buildThinLTODefaultPipeline(
952     OptimizationLevel Level, bool DebugLogging,
953     const ModuleSummaryIndex *ImportSummary) {
954   ModulePassManager MPM(DebugLogging);
955 
956   if (ImportSummary) {
957     // These passes import type identifier resolutions for whole-program
958     // devirtualization and CFI. They must run early because other passes may
959     // disturb the specific instruction patterns that these passes look for,
960     // creating dependencies on resolutions that may not appear in the summary.
961     //
962     // For example, GVN may transform the pattern assume(type.test) appearing in
963     // two basic blocks into assume(phi(type.test, type.test)), which would
964     // transform a dependency on a WPD resolution into a dependency on a type
965     // identifier resolution for CFI.
966     //
967     // Also, WPD has access to more precise information than ICP and can
968     // devirtualize more effectively, so it should operate on the IR first.
969     MPM.addPass(WholeProgramDevirtPass(nullptr, ImportSummary));
970     MPM.addPass(LowerTypeTestsPass(nullptr, ImportSummary));
971   }
972 
973   // Force any function attributes we want the rest of the pipeline to observe.
974   MPM.addPass(ForceFunctionAttrsPass());
975 
976   // During the ThinLTO backend phase we perform early indirect call promotion
977   // here, before globalopt. Otherwise imported available_externally functions
978   // look unreferenced and are removed.
979   // FIXME: move this into buildModuleSimplificationPipeline to merge the logic
980   //        with SamplePGO.
981   if (!PGOOpt || PGOOpt->SampleProfileFile.empty())
982     MPM.addPass(PGOIndirectCallPromotion(true /* InLTO */,
983                                          false /* SamplePGO */));
984 
985   // Add the core simplification pipeline.
986   MPM.addPass(buildModuleSimplificationPipeline(Level, ThinLTOPhase::PostLink,
987                                                 DebugLogging));
988 
989   // Now add the optimization pipeline.
990   MPM.addPass(buildModuleOptimizationPipeline(Level, DebugLogging));
991 
992   return MPM;
993 }
994 
995 ModulePassManager
996 PassBuilder::buildLTOPreLinkDefaultPipeline(OptimizationLevel Level,
997                                             bool DebugLogging) {
998   assert(Level != O0 && "Must request optimizations for the default pipeline!");
999   // FIXME: We should use a customized pre-link pipeline!
1000   return buildPerModuleDefaultPipeline(Level, DebugLogging);
1001 }
1002 
1003 ModulePassManager
1004 PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level, bool DebugLogging,
1005                                      ModuleSummaryIndex *ExportSummary) {
1006   assert(Level != O0 && "Must request optimizations for the default pipeline!");
1007   ModulePassManager MPM(DebugLogging);
1008 
1009   if (PGOOpt && !PGOOpt->SampleProfileFile.empty()) {
1010     // Load sample profile before running the LTO optimization pipeline.
1011     MPM.addPass(SampleProfileLoaderPass(PGOOpt->SampleProfileFile,
1012                                         PGOOpt->ProfileRemappingFile,
1013                                         false /* ThinLTOPhase::PreLink */));
1014   }
1015 
1016   // Remove unused virtual tables to improve the quality of code generated by
1017   // whole-program devirtualization and bitset lowering.
1018   MPM.addPass(GlobalDCEPass());
1019 
1020   // Force any function attributes we want the rest of the pipeline to observe.
1021   MPM.addPass(ForceFunctionAttrsPass());
1022 
1023   // Do basic inference of function attributes from known properties of system
1024   // libraries and other oracles.
1025   MPM.addPass(InferFunctionAttrsPass());
1026 
1027   if (Level > 1) {
1028     FunctionPassManager EarlyFPM(DebugLogging);
1029     EarlyFPM.addPass(CallSiteSplittingPass());
1030     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(EarlyFPM)));
1031 
1032     // Indirect call promotion. This should promote all the targets that are
1033     // left by the earlier promotion pass that promotes intra-module targets.
1034     // This two-step promotion is to save the compile time. For LTO, it should
1035     // produce the same result as if we only do promotion here.
1036     MPM.addPass(PGOIndirectCallPromotion(
1037         true /* InLTO */, PGOOpt && !PGOOpt->SampleProfileFile.empty()));
1038     // Propagate constants at call sites into the functions they call.  This
1039     // opens opportunities for globalopt (and inlining) by substituting function
1040     // pointers passed as arguments to direct uses of functions.
1041    MPM.addPass(IPSCCPPass());
1042 
1043    // Attach metadata to indirect call sites indicating the set of functions
1044    // they may target at run-time. This should follow IPSCCP.
1045    MPM.addPass(CalledValuePropagationPass());
1046   }
1047 
1048   // Now deduce any function attributes based in the current code.
1049   MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(
1050               PostOrderFunctionAttrsPass()));
1051 
1052   // Do RPO function attribute inference across the module to forward-propagate
1053   // attributes where applicable.
1054   // FIXME: Is this really an optimization rather than a canonicalization?
1055   MPM.addPass(ReversePostOrderFunctionAttrsPass());
1056 
1057   // Use inragne annotations on GEP indices to split globals where beneficial.
1058   MPM.addPass(GlobalSplitPass());
1059 
1060   // Run whole program optimization of virtual call when the list of callees
1061   // is fixed.
1062   MPM.addPass(WholeProgramDevirtPass(ExportSummary, nullptr));
1063 
1064   // Stop here at -O1.
1065   if (Level == 1) {
1066     // The LowerTypeTestsPass needs to run to lower type metadata and the
1067     // type.test intrinsics. The pass does nothing if CFI is disabled.
1068     MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
1069     return MPM;
1070   }
1071 
1072   // Optimize globals to try and fold them into constants.
1073   MPM.addPass(GlobalOptPass());
1074 
1075   // Promote any localized globals to SSA registers.
1076   MPM.addPass(createModuleToFunctionPassAdaptor(PromotePass()));
1077 
1078   // Linking modules together can lead to duplicate global constant, only
1079   // keep one copy of each constant.
1080   MPM.addPass(ConstantMergePass());
1081 
1082   // Remove unused arguments from functions.
1083   MPM.addPass(DeadArgumentEliminationPass());
1084 
1085   // Reduce the code after globalopt and ipsccp.  Both can open up significant
1086   // simplification opportunities, and both can propagate functions through
1087   // function pointers.  When this happens, we often have to resolve varargs
1088   // calls, etc, so let instcombine do this.
1089   FunctionPassManager PeepholeFPM(DebugLogging);
1090   if (Level == O3)
1091     PeepholeFPM.addPass(AggressiveInstCombinePass());
1092   PeepholeFPM.addPass(InstCombinePass());
1093   invokePeepholeEPCallbacks(PeepholeFPM, Level);
1094 
1095   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(PeepholeFPM)));
1096 
1097   // Note: historically, the PruneEH pass was run first to deduce nounwind and
1098   // generally clean up exception handling overhead. It isn't clear this is
1099   // valuable as the inliner doesn't currently care whether it is inlining an
1100   // invoke or a call.
1101   // Run the inliner now.
1102   MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(
1103       InlinerPass(getInlineParamsFromOptLevel(Level))));
1104 
1105   // Optimize globals again after we ran the inliner.
1106   MPM.addPass(GlobalOptPass());
1107 
1108   // Garbage collect dead functions.
1109   // FIXME: Add ArgumentPromotion pass after once it's ported.
1110   MPM.addPass(GlobalDCEPass());
1111 
1112   FunctionPassManager FPM(DebugLogging);
1113   // The IPO Passes may leave cruft around. Clean up after them.
1114   FPM.addPass(InstCombinePass());
1115   invokePeepholeEPCallbacks(FPM, Level);
1116 
1117   FPM.addPass(JumpThreadingPass());
1118 
1119   // Break up allocas
1120   FPM.addPass(SROA());
1121 
1122   // Run a few AA driver optimizations here and now to cleanup the code.
1123   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
1124 
1125   MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(
1126               PostOrderFunctionAttrsPass()));
1127   // FIXME: here we run IP alias analysis in the legacy PM.
1128 
1129   FunctionPassManager MainFPM;
1130 
1131   // FIXME: once we fix LoopPass Manager, add LICM here.
1132   // FIXME: once we provide support for enabling MLSM, add it here.
1133   // FIXME: once we provide support for enabling NewGVN, add it here.
1134   if (RunNewGVN)
1135     MainFPM.addPass(NewGVNPass());
1136   else
1137     MainFPM.addPass(GVN());
1138 
1139   // Remove dead memcpy()'s.
1140   MainFPM.addPass(MemCpyOptPass());
1141 
1142   // Nuke dead stores.
1143   MainFPM.addPass(DSEPass());
1144 
1145   // FIXME: at this point, we run a bunch of loop passes:
1146   // indVarSimplify, loopDeletion, loopInterchange, loopUnrool,
1147   // loopVectorize. Enable them once the remaining issue with LPM
1148   // are sorted out.
1149 
1150   MainFPM.addPass(InstCombinePass());
1151   MainFPM.addPass(SimplifyCFGPass());
1152   MainFPM.addPass(SCCPPass());
1153   MainFPM.addPass(InstCombinePass());
1154   MainFPM.addPass(BDCEPass());
1155 
1156   // FIXME: We may want to run SLPVectorizer here.
1157   // After vectorization, assume intrinsics may tell us more
1158   // about pointer alignments.
1159 #if 0
1160   MainFPM.add(AlignmentFromAssumptionsPass());
1161 #endif
1162 
1163   // FIXME: Conditionally run LoadCombine here, after it's ported
1164   // (in case we still have this pass, given its questionable usefulness).
1165 
1166   MainFPM.addPass(InstCombinePass());
1167   invokePeepholeEPCallbacks(MainFPM, Level);
1168   MainFPM.addPass(JumpThreadingPass());
1169   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(MainFPM)));
1170 
1171   // Create a function that performs CFI checks for cross-DSO calls with
1172   // targets in the current module.
1173   MPM.addPass(CrossDSOCFIPass());
1174 
1175   // Lower type metadata and the type.test intrinsic. This pass supports
1176   // clang's control flow integrity mechanisms (-fsanitize=cfi*) and needs
1177   // to be run at link time if CFI is enabled. This pass does nothing if
1178   // CFI is disabled.
1179   MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
1180 
1181   // Add late LTO optimization passes.
1182   // Delete basic blocks, which optimization passes may have killed.
1183   MPM.addPass(createModuleToFunctionPassAdaptor(SimplifyCFGPass()));
1184 
1185   // Drop bodies of available eternally objects to improve GlobalDCE.
1186   MPM.addPass(EliminateAvailableExternallyPass());
1187 
1188   // Now that we have optimized the program, discard unreachable functions.
1189   MPM.addPass(GlobalDCEPass());
1190 
1191   // FIXME: Enable MergeFuncs, conditionally, after ported, maybe.
1192   return MPM;
1193 }
1194 
1195 AAManager PassBuilder::buildDefaultAAPipeline() {
1196   AAManager AA;
1197 
1198   // The order in which these are registered determines their priority when
1199   // being queried.
1200 
1201   // First we register the basic alias analysis that provides the majority of
1202   // per-function local AA logic. This is a stateless, on-demand local set of
1203   // AA techniques.
1204   AA.registerFunctionAnalysis<BasicAA>();
1205 
1206   // Next we query fast, specialized alias analyses that wrap IR-embedded
1207   // information about aliasing.
1208   AA.registerFunctionAnalysis<ScopedNoAliasAA>();
1209   AA.registerFunctionAnalysis<TypeBasedAA>();
1210 
1211   // Add support for querying global aliasing information when available.
1212   // Because the `AAManager` is a function analysis and `GlobalsAA` is a module
1213   // analysis, all that the `AAManager` can do is query for any *cached*
1214   // results from `GlobalsAA` through a readonly proxy.
1215   AA.registerModuleAnalysis<GlobalsAA>();
1216 
1217   return AA;
1218 }
1219 
1220 static Optional<int> parseRepeatPassName(StringRef Name) {
1221   if (!Name.consume_front("repeat<") || !Name.consume_back(">"))
1222     return None;
1223   int Count;
1224   if (Name.getAsInteger(0, Count) || Count <= 0)
1225     return None;
1226   return Count;
1227 }
1228 
1229 static Optional<int> parseDevirtPassName(StringRef Name) {
1230   if (!Name.consume_front("devirt<") || !Name.consume_back(">"))
1231     return None;
1232   int Count;
1233   if (Name.getAsInteger(0, Count) || Count <= 0)
1234     return None;
1235   return Count;
1236 }
1237 
1238 /// Tests whether a pass name starts with a valid prefix for a default pipeline
1239 /// alias.
1240 static bool startsWithDefaultPipelineAliasPrefix(StringRef Name) {
1241   return Name.startswith("default") || Name.startswith("thinlto") ||
1242          Name.startswith("lto");
1243 }
1244 
1245 /// Tests whether registered callbacks will accept a given pass name.
1246 ///
1247 /// When parsing a pipeline text, the type of the outermost pipeline may be
1248 /// omitted, in which case the type is automatically determined from the first
1249 /// pass name in the text. This may be a name that is handled through one of the
1250 /// callbacks. We check this through the oridinary parsing callbacks by setting
1251 /// up a dummy PassManager in order to not force the client to also handle this
1252 /// type of query.
1253 template <typename PassManagerT, typename CallbacksT>
1254 static bool callbacksAcceptPassName(StringRef Name, CallbacksT &Callbacks) {
1255   if (!Callbacks.empty()) {
1256     PassManagerT DummyPM;
1257     for (auto &CB : Callbacks)
1258       if (CB(Name, DummyPM, {}))
1259         return true;
1260   }
1261   return false;
1262 }
1263 
1264 template <typename CallbacksT>
1265 static bool isModulePassName(StringRef Name, CallbacksT &Callbacks) {
1266   // Manually handle aliases for pre-configured pipeline fragments.
1267   if (startsWithDefaultPipelineAliasPrefix(Name))
1268     return DefaultAliasRegex.match(Name);
1269 
1270   // Explicitly handle pass manager names.
1271   if (Name == "module")
1272     return true;
1273   if (Name == "cgscc")
1274     return true;
1275   if (Name == "function")
1276     return true;
1277 
1278   // Explicitly handle custom-parsed pass names.
1279   if (parseRepeatPassName(Name))
1280     return true;
1281 
1282 #define MODULE_PASS(NAME, CREATE_PASS)                                         \
1283   if (Name == NAME)                                                            \
1284     return true;
1285 #define MODULE_ANALYSIS(NAME, CREATE_PASS)                                     \
1286   if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">")           \
1287     return true;
1288 #include "PassRegistry.def"
1289 
1290   return callbacksAcceptPassName<ModulePassManager>(Name, Callbacks);
1291 }
1292 
1293 template <typename CallbacksT>
1294 static bool isCGSCCPassName(StringRef Name, CallbacksT &Callbacks) {
1295   // Explicitly handle pass manager names.
1296   if (Name == "cgscc")
1297     return true;
1298   if (Name == "function")
1299     return true;
1300 
1301   // Explicitly handle custom-parsed pass names.
1302   if (parseRepeatPassName(Name))
1303     return true;
1304   if (parseDevirtPassName(Name))
1305     return true;
1306 
1307 #define CGSCC_PASS(NAME, CREATE_PASS)                                          \
1308   if (Name == NAME)                                                            \
1309     return true;
1310 #define CGSCC_ANALYSIS(NAME, CREATE_PASS)                                      \
1311   if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">")           \
1312     return true;
1313 #include "PassRegistry.def"
1314 
1315   return callbacksAcceptPassName<CGSCCPassManager>(Name, Callbacks);
1316 }
1317 
1318 template <typename CallbacksT>
1319 static bool isFunctionPassName(StringRef Name, CallbacksT &Callbacks) {
1320   // Explicitly handle pass manager names.
1321   if (Name == "function")
1322     return true;
1323   if (Name == "loop")
1324     return true;
1325 
1326   // Explicitly handle custom-parsed pass names.
1327   if (parseRepeatPassName(Name))
1328     return true;
1329 
1330 #define FUNCTION_PASS(NAME, CREATE_PASS)                                       \
1331   if (Name == NAME)                                                            \
1332     return true;
1333 #define FUNCTION_ANALYSIS(NAME, CREATE_PASS)                                   \
1334   if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">")           \
1335     return true;
1336 #include "PassRegistry.def"
1337 
1338   return callbacksAcceptPassName<FunctionPassManager>(Name, Callbacks);
1339 }
1340 
1341 template <typename CallbacksT>
1342 static bool isLoopPassName(StringRef Name, CallbacksT &Callbacks) {
1343   // Explicitly handle pass manager names.
1344   if (Name == "loop")
1345     return true;
1346 
1347   // Explicitly handle custom-parsed pass names.
1348   if (parseRepeatPassName(Name))
1349     return true;
1350 
1351 #define LOOP_PASS(NAME, CREATE_PASS)                                           \
1352   if (Name == NAME)                                                            \
1353     return true;
1354 #define LOOP_ANALYSIS(NAME, CREATE_PASS)                                       \
1355   if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">")           \
1356     return true;
1357 #include "PassRegistry.def"
1358 
1359   return callbacksAcceptPassName<LoopPassManager>(Name, Callbacks);
1360 }
1361 
1362 Optional<std::vector<PassBuilder::PipelineElement>>
1363 PassBuilder::parsePipelineText(StringRef Text) {
1364   std::vector<PipelineElement> ResultPipeline;
1365 
1366   SmallVector<std::vector<PipelineElement> *, 4> PipelineStack = {
1367       &ResultPipeline};
1368   for (;;) {
1369     std::vector<PipelineElement> &Pipeline = *PipelineStack.back();
1370     size_t Pos = Text.find_first_of(",()");
1371     Pipeline.push_back({Text.substr(0, Pos), {}});
1372 
1373     // If we have a single terminating name, we're done.
1374     if (Pos == Text.npos)
1375       break;
1376 
1377     char Sep = Text[Pos];
1378     Text = Text.substr(Pos + 1);
1379     if (Sep == ',')
1380       // Just a name ending in a comma, continue.
1381       continue;
1382 
1383     if (Sep == '(') {
1384       // Push the inner pipeline onto the stack to continue processing.
1385       PipelineStack.push_back(&Pipeline.back().InnerPipeline);
1386       continue;
1387     }
1388 
1389     assert(Sep == ')' && "Bogus separator!");
1390     // When handling the close parenthesis, we greedily consume them to avoid
1391     // empty strings in the pipeline.
1392     do {
1393       // If we try to pop the outer pipeline we have unbalanced parentheses.
1394       if (PipelineStack.size() == 1)
1395         return None;
1396 
1397       PipelineStack.pop_back();
1398     } while (Text.consume_front(")"));
1399 
1400     // Check if we've finished parsing.
1401     if (Text.empty())
1402       break;
1403 
1404     // Otherwise, the end of an inner pipeline always has to be followed by
1405     // a comma, and then we can continue.
1406     if (!Text.consume_front(","))
1407       return None;
1408   }
1409 
1410   if (PipelineStack.size() > 1)
1411     // Unbalanced paretheses.
1412     return None;
1413 
1414   assert(PipelineStack.back() == &ResultPipeline &&
1415          "Wrong pipeline at the bottom of the stack!");
1416   return {std::move(ResultPipeline)};
1417 }
1418 
1419 Error PassBuilder::parseModulePass(ModulePassManager &MPM,
1420                                    const PipelineElement &E,
1421                                    bool VerifyEachPass, bool DebugLogging) {
1422   auto &Name = E.Name;
1423   auto &InnerPipeline = E.InnerPipeline;
1424 
1425   // First handle complex passes like the pass managers which carry pipelines.
1426   if (!InnerPipeline.empty()) {
1427     if (Name == "module") {
1428       ModulePassManager NestedMPM(DebugLogging);
1429       if (auto Err = parseModulePassPipeline(NestedMPM, InnerPipeline,
1430                                              VerifyEachPass, DebugLogging))
1431         return Err;
1432       MPM.addPass(std::move(NestedMPM));
1433       return Error::success();
1434     }
1435     if (Name == "cgscc") {
1436       CGSCCPassManager CGPM(DebugLogging);
1437       if (auto Err = parseCGSCCPassPipeline(CGPM, InnerPipeline, VerifyEachPass,
1438                                             DebugLogging))
1439         return Err;
1440       MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
1441       return Error::success();
1442     }
1443     if (Name == "function") {
1444       FunctionPassManager FPM(DebugLogging);
1445       if (auto Err = parseFunctionPassPipeline(FPM, InnerPipeline,
1446                                                VerifyEachPass, DebugLogging))
1447         return Err;
1448       MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
1449       return Error::success();
1450     }
1451     if (auto Count = parseRepeatPassName(Name)) {
1452       ModulePassManager NestedMPM(DebugLogging);
1453       if (auto Err = parseModulePassPipeline(NestedMPM, InnerPipeline,
1454                                              VerifyEachPass, DebugLogging))
1455         return Err;
1456       MPM.addPass(createRepeatedPass(*Count, std::move(NestedMPM)));
1457       return Error::success();
1458     }
1459 
1460     for (auto &C : ModulePipelineParsingCallbacks)
1461       if (C(Name, MPM, InnerPipeline))
1462         return Error::success();
1463 
1464     // Normal passes can't have pipelines.
1465     return make_error<StringError>(
1466         formatv("invalid use of '{0}' pass as module pipeline", Name).str(),
1467         inconvertibleErrorCode());
1468     ;
1469   }
1470 
1471   // Manually handle aliases for pre-configured pipeline fragments.
1472   if (startsWithDefaultPipelineAliasPrefix(Name)) {
1473     SmallVector<StringRef, 3> Matches;
1474     if (!DefaultAliasRegex.match(Name, &Matches))
1475       return make_error<StringError>(
1476           formatv("unknown default pipeline alias '{0}'", Name).str(),
1477           inconvertibleErrorCode());
1478 
1479     assert(Matches.size() == 3 && "Must capture two matched strings!");
1480 
1481     OptimizationLevel L = StringSwitch<OptimizationLevel>(Matches[2])
1482                               .Case("O0", O0)
1483                               .Case("O1", O1)
1484                               .Case("O2", O2)
1485                               .Case("O3", O3)
1486                               .Case("Os", Os)
1487                               .Case("Oz", Oz);
1488     if (L == O0)
1489       // At O0 we do nothing at all!
1490       return Error::success();
1491 
1492     if (Matches[1] == "default") {
1493       MPM.addPass(buildPerModuleDefaultPipeline(L, DebugLogging));
1494     } else if (Matches[1] == "thinlto-pre-link") {
1495       MPM.addPass(buildThinLTOPreLinkDefaultPipeline(L, DebugLogging));
1496     } else if (Matches[1] == "thinlto") {
1497       MPM.addPass(buildThinLTODefaultPipeline(L, DebugLogging, nullptr));
1498     } else if (Matches[1] == "lto-pre-link") {
1499       MPM.addPass(buildLTOPreLinkDefaultPipeline(L, DebugLogging));
1500     } else {
1501       assert(Matches[1] == "lto" && "Not one of the matched options!");
1502       MPM.addPass(buildLTODefaultPipeline(L, DebugLogging, nullptr));
1503     }
1504     return Error::success();
1505   }
1506 
1507   // Finally expand the basic registered passes from the .inc file.
1508 #define MODULE_PASS(NAME, CREATE_PASS)                                         \
1509   if (Name == NAME) {                                                          \
1510     MPM.addPass(CREATE_PASS);                                                  \
1511     return Error::success();                                                   \
1512   }
1513 #define MODULE_ANALYSIS(NAME, CREATE_PASS)                                     \
1514   if (Name == "require<" NAME ">") {                                           \
1515     MPM.addPass(                                                               \
1516         RequireAnalysisPass<                                                   \
1517             std::remove_reference<decltype(CREATE_PASS)>::type, Module>());    \
1518     return Error::success();                                                   \
1519   }                                                                            \
1520   if (Name == "invalidate<" NAME ">") {                                        \
1521     MPM.addPass(InvalidateAnalysisPass<                                        \
1522                 std::remove_reference<decltype(CREATE_PASS)>::type>());        \
1523     return Error::success();                                                   \
1524   }
1525 #include "PassRegistry.def"
1526 
1527   for (auto &C : ModulePipelineParsingCallbacks)
1528     if (C(Name, MPM, InnerPipeline))
1529       return Error::success();
1530   return make_error<StringError>(
1531       formatv("unknown module pass '{0}'", Name).str(),
1532       inconvertibleErrorCode());
1533 }
1534 
1535 Error PassBuilder::parseCGSCCPass(CGSCCPassManager &CGPM,
1536                                   const PipelineElement &E, bool VerifyEachPass,
1537                                   bool DebugLogging) {
1538   auto &Name = E.Name;
1539   auto &InnerPipeline = E.InnerPipeline;
1540 
1541   // First handle complex passes like the pass managers which carry pipelines.
1542   if (!InnerPipeline.empty()) {
1543     if (Name == "cgscc") {
1544       CGSCCPassManager NestedCGPM(DebugLogging);
1545       if (auto Err = parseCGSCCPassPipeline(NestedCGPM, InnerPipeline,
1546                                             VerifyEachPass, DebugLogging))
1547         return Err;
1548       // Add the nested pass manager with the appropriate adaptor.
1549       CGPM.addPass(std::move(NestedCGPM));
1550       return Error::success();
1551     }
1552     if (Name == "function") {
1553       FunctionPassManager FPM(DebugLogging);
1554       if (auto Err = parseFunctionPassPipeline(FPM, InnerPipeline,
1555                                                VerifyEachPass, DebugLogging))
1556         return Err;
1557       // Add the nested pass manager with the appropriate adaptor.
1558       CGPM.addPass(createCGSCCToFunctionPassAdaptor(std::move(FPM)));
1559       return Error::success();
1560     }
1561     if (auto Count = parseRepeatPassName(Name)) {
1562       CGSCCPassManager NestedCGPM(DebugLogging);
1563       if (auto Err = parseCGSCCPassPipeline(NestedCGPM, InnerPipeline,
1564                                             VerifyEachPass, DebugLogging))
1565         return Err;
1566       CGPM.addPass(createRepeatedPass(*Count, std::move(NestedCGPM)));
1567       return Error::success();
1568     }
1569     if (auto MaxRepetitions = parseDevirtPassName(Name)) {
1570       CGSCCPassManager NestedCGPM(DebugLogging);
1571       if (auto Err = parseCGSCCPassPipeline(NestedCGPM, InnerPipeline,
1572                                             VerifyEachPass, DebugLogging))
1573         return Err;
1574       CGPM.addPass(
1575           createDevirtSCCRepeatedPass(std::move(NestedCGPM), *MaxRepetitions));
1576       return Error::success();
1577     }
1578 
1579     for (auto &C : CGSCCPipelineParsingCallbacks)
1580       if (C(Name, CGPM, InnerPipeline))
1581         return Error::success();
1582 
1583     // Normal passes can't have pipelines.
1584     return make_error<StringError>(
1585         formatv("invalid use of '{0}' pass as cgscc pipeline", Name).str(),
1586         inconvertibleErrorCode());
1587   }
1588 
1589 // Now expand the basic registered passes from the .inc file.
1590 #define CGSCC_PASS(NAME, CREATE_PASS)                                          \
1591   if (Name == NAME) {                                                          \
1592     CGPM.addPass(CREATE_PASS);                                                 \
1593     return Error::success();                                                   \
1594   }
1595 #define CGSCC_ANALYSIS(NAME, CREATE_PASS)                                      \
1596   if (Name == "require<" NAME ">") {                                           \
1597     CGPM.addPass(RequireAnalysisPass<                                          \
1598                  std::remove_reference<decltype(CREATE_PASS)>::type,           \
1599                  LazyCallGraph::SCC, CGSCCAnalysisManager, LazyCallGraph &,    \
1600                  CGSCCUpdateResult &>());                                      \
1601     return Error::success();                                                   \
1602   }                                                                            \
1603   if (Name == "invalidate<" NAME ">") {                                        \
1604     CGPM.addPass(InvalidateAnalysisPass<                                       \
1605                  std::remove_reference<decltype(CREATE_PASS)>::type>());       \
1606     return Error::success();                                                   \
1607   }
1608 #include "PassRegistry.def"
1609 
1610   for (auto &C : CGSCCPipelineParsingCallbacks)
1611     if (C(Name, CGPM, InnerPipeline))
1612       return Error::success();
1613   return make_error<StringError>(
1614       formatv("unknown cgscc pass '{0}'", Name).str(),
1615       inconvertibleErrorCode());
1616 }
1617 
1618 Error PassBuilder::parseFunctionPass(FunctionPassManager &FPM,
1619                                      const PipelineElement &E,
1620                                      bool VerifyEachPass, bool DebugLogging) {
1621   auto &Name = E.Name;
1622   auto &InnerPipeline = E.InnerPipeline;
1623 
1624   // First handle complex passes like the pass managers which carry pipelines.
1625   if (!InnerPipeline.empty()) {
1626     if (Name == "function") {
1627       FunctionPassManager NestedFPM(DebugLogging);
1628       if (auto Err = parseFunctionPassPipeline(NestedFPM, InnerPipeline,
1629                                                VerifyEachPass, DebugLogging))
1630         return Err;
1631       // Add the nested pass manager with the appropriate adaptor.
1632       FPM.addPass(std::move(NestedFPM));
1633       return Error::success();
1634     }
1635     if (Name == "loop") {
1636       LoopPassManager LPM(DebugLogging);
1637       if (auto Err = parseLoopPassPipeline(LPM, InnerPipeline, VerifyEachPass,
1638                                            DebugLogging))
1639         return Err;
1640       // Add the nested pass manager with the appropriate adaptor.
1641       FPM.addPass(
1642           createFunctionToLoopPassAdaptor(std::move(LPM), DebugLogging));
1643       return Error::success();
1644     }
1645     if (auto Count = parseRepeatPassName(Name)) {
1646       FunctionPassManager NestedFPM(DebugLogging);
1647       if (auto Err = parseFunctionPassPipeline(NestedFPM, InnerPipeline,
1648                                                VerifyEachPass, DebugLogging))
1649         return Err;
1650       FPM.addPass(createRepeatedPass(*Count, std::move(NestedFPM)));
1651       return Error::success();
1652     }
1653 
1654     for (auto &C : FunctionPipelineParsingCallbacks)
1655       if (C(Name, FPM, InnerPipeline))
1656         return Error::success();
1657 
1658     // Normal passes can't have pipelines.
1659     return make_error<StringError>(
1660         formatv("invalid use of '{0}' pass as function pipeline", Name).str(),
1661         inconvertibleErrorCode());
1662   }
1663 
1664 // Now expand the basic registered passes from the .inc file.
1665 #define FUNCTION_PASS(NAME, CREATE_PASS)                                       \
1666   if (Name == NAME) {                                                          \
1667     FPM.addPass(CREATE_PASS);                                                  \
1668     return Error::success();                                                   \
1669   }
1670 #define FUNCTION_ANALYSIS(NAME, CREATE_PASS)                                   \
1671   if (Name == "require<" NAME ">") {                                           \
1672     FPM.addPass(                                                               \
1673         RequireAnalysisPass<                                                   \
1674             std::remove_reference<decltype(CREATE_PASS)>::type, Function>());  \
1675     return Error::success();                                                   \
1676   }                                                                            \
1677   if (Name == "invalidate<" NAME ">") {                                        \
1678     FPM.addPass(InvalidateAnalysisPass<                                        \
1679                 std::remove_reference<decltype(CREATE_PASS)>::type>());        \
1680     return Error::success();                                                   \
1681   }
1682 #include "PassRegistry.def"
1683 
1684   for (auto &C : FunctionPipelineParsingCallbacks)
1685     if (C(Name, FPM, InnerPipeline))
1686       return Error::success();
1687   return make_error<StringError>(
1688       formatv("unknown function pass '{0}'", Name).str(),
1689       inconvertibleErrorCode());
1690 }
1691 
1692 Error PassBuilder::parseLoopPass(LoopPassManager &LPM, const PipelineElement &E,
1693                                  bool VerifyEachPass, bool DebugLogging) {
1694   StringRef Name = E.Name;
1695   auto &InnerPipeline = E.InnerPipeline;
1696 
1697   // First handle complex passes like the pass managers which carry pipelines.
1698   if (!InnerPipeline.empty()) {
1699     if (Name == "loop") {
1700       LoopPassManager NestedLPM(DebugLogging);
1701       if (auto Err = parseLoopPassPipeline(NestedLPM, InnerPipeline,
1702                                            VerifyEachPass, DebugLogging))
1703         return Err;
1704       // Add the nested pass manager with the appropriate adaptor.
1705       LPM.addPass(std::move(NestedLPM));
1706       return Error::success();
1707     }
1708     if (auto Count = parseRepeatPassName(Name)) {
1709       LoopPassManager NestedLPM(DebugLogging);
1710       if (auto Err = parseLoopPassPipeline(NestedLPM, InnerPipeline,
1711                                            VerifyEachPass, DebugLogging))
1712         return Err;
1713       LPM.addPass(createRepeatedPass(*Count, std::move(NestedLPM)));
1714       return Error::success();
1715     }
1716 
1717     for (auto &C : LoopPipelineParsingCallbacks)
1718       if (C(Name, LPM, InnerPipeline))
1719         return Error::success();
1720 
1721     // Normal passes can't have pipelines.
1722     return make_error<StringError>(
1723         formatv("invalid use of '{0}' pass as loop pipeline", Name).str(),
1724         inconvertibleErrorCode());
1725   }
1726 
1727 // Now expand the basic registered passes from the .inc file.
1728 #define LOOP_PASS(NAME, CREATE_PASS)                                           \
1729   if (Name == NAME) {                                                          \
1730     LPM.addPass(CREATE_PASS);                                                  \
1731     return Error::success();                                                   \
1732   }
1733 #define LOOP_ANALYSIS(NAME, CREATE_PASS)                                       \
1734   if (Name == "require<" NAME ">") {                                           \
1735     LPM.addPass(RequireAnalysisPass<                                           \
1736                 std::remove_reference<decltype(CREATE_PASS)>::type, Loop,      \
1737                 LoopAnalysisManager, LoopStandardAnalysisResults &,            \
1738                 LPMUpdater &>());                                              \
1739     return Error::success();                                                   \
1740   }                                                                            \
1741   if (Name == "invalidate<" NAME ">") {                                        \
1742     LPM.addPass(InvalidateAnalysisPass<                                        \
1743                 std::remove_reference<decltype(CREATE_PASS)>::type>());        \
1744     return Error::success();                                                   \
1745   }
1746 #include "PassRegistry.def"
1747 
1748   for (auto &C : LoopPipelineParsingCallbacks)
1749     if (C(Name, LPM, InnerPipeline))
1750       return Error::success();
1751   return make_error<StringError>(formatv("unknown loop pass '{0}'", Name).str(),
1752                                  inconvertibleErrorCode());
1753 }
1754 
1755 bool PassBuilder::parseAAPassName(AAManager &AA, StringRef Name) {
1756 #define MODULE_ALIAS_ANALYSIS(NAME, CREATE_PASS)                               \
1757   if (Name == NAME) {                                                          \
1758     AA.registerModuleAnalysis<                                                 \
1759         std::remove_reference<decltype(CREATE_PASS)>::type>();                 \
1760     return true;                                                               \
1761   }
1762 #define FUNCTION_ALIAS_ANALYSIS(NAME, CREATE_PASS)                             \
1763   if (Name == NAME) {                                                          \
1764     AA.registerFunctionAnalysis<                                               \
1765         std::remove_reference<decltype(CREATE_PASS)>::type>();                 \
1766     return true;                                                               \
1767   }
1768 #include "PassRegistry.def"
1769 
1770   for (auto &C : AAParsingCallbacks)
1771     if (C(Name, AA))
1772       return true;
1773   return false;
1774 }
1775 
1776 Error PassBuilder::parseLoopPassPipeline(LoopPassManager &LPM,
1777                                          ArrayRef<PipelineElement> Pipeline,
1778                                          bool VerifyEachPass,
1779                                          bool DebugLogging) {
1780   for (const auto &Element : Pipeline) {
1781     if (auto Err = parseLoopPass(LPM, Element, VerifyEachPass, DebugLogging))
1782       return Err;
1783     // FIXME: No verifier support for Loop passes!
1784   }
1785   return Error::success();
1786 }
1787 
1788 Error PassBuilder::parseFunctionPassPipeline(FunctionPassManager &FPM,
1789                                              ArrayRef<PipelineElement> Pipeline,
1790                                              bool VerifyEachPass,
1791                                              bool DebugLogging) {
1792   for (const auto &Element : Pipeline) {
1793     if (auto Err =
1794             parseFunctionPass(FPM, Element, VerifyEachPass, DebugLogging))
1795       return Err;
1796     if (VerifyEachPass)
1797       FPM.addPass(VerifierPass());
1798   }
1799   return Error::success();
1800 }
1801 
1802 Error PassBuilder::parseCGSCCPassPipeline(CGSCCPassManager &CGPM,
1803                                           ArrayRef<PipelineElement> Pipeline,
1804                                           bool VerifyEachPass,
1805                                           bool DebugLogging) {
1806   for (const auto &Element : Pipeline) {
1807     if (auto Err = parseCGSCCPass(CGPM, Element, VerifyEachPass, DebugLogging))
1808       return Err;
1809     // FIXME: No verifier support for CGSCC passes!
1810   }
1811   return Error::success();
1812 }
1813 
1814 void PassBuilder::crossRegisterProxies(LoopAnalysisManager &LAM,
1815                                        FunctionAnalysisManager &FAM,
1816                                        CGSCCAnalysisManager &CGAM,
1817                                        ModuleAnalysisManager &MAM) {
1818   MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(FAM); });
1819   MAM.registerPass([&] { return CGSCCAnalysisManagerModuleProxy(CGAM); });
1820   CGAM.registerPass([&] { return ModuleAnalysisManagerCGSCCProxy(MAM); });
1821   FAM.registerPass([&] { return CGSCCAnalysisManagerFunctionProxy(CGAM); });
1822   FAM.registerPass([&] { return ModuleAnalysisManagerFunctionProxy(MAM); });
1823   FAM.registerPass([&] { return LoopAnalysisManagerFunctionProxy(LAM); });
1824   LAM.registerPass([&] { return FunctionAnalysisManagerLoopProxy(FAM); });
1825 }
1826 
1827 Error PassBuilder::parseModulePassPipeline(ModulePassManager &MPM,
1828                                            ArrayRef<PipelineElement> Pipeline,
1829                                            bool VerifyEachPass,
1830                                            bool DebugLogging) {
1831   for (const auto &Element : Pipeline) {
1832     if (auto Err = parseModulePass(MPM, Element, VerifyEachPass, DebugLogging))
1833       return Err;
1834     if (VerifyEachPass)
1835       MPM.addPass(VerifierPass());
1836   }
1837   return Error::success();
1838 }
1839 
1840 // Primary pass pipeline description parsing routine for a \c ModulePassManager
1841 // FIXME: Should this routine accept a TargetMachine or require the caller to
1842 // pre-populate the analysis managers with target-specific stuff?
1843 Error PassBuilder::parsePassPipeline(ModulePassManager &MPM,
1844                                      StringRef PipelineText,
1845                                      bool VerifyEachPass, bool DebugLogging) {
1846   auto Pipeline = parsePipelineText(PipelineText);
1847   if (!Pipeline || Pipeline->empty())
1848     return make_error<StringError>(
1849         formatv("invalid pipeline '{0}'", PipelineText).str(),
1850         inconvertibleErrorCode());
1851 
1852   // If the first name isn't at the module layer, wrap the pipeline up
1853   // automatically.
1854   StringRef FirstName = Pipeline->front().Name;
1855 
1856   if (!isModulePassName(FirstName, ModulePipelineParsingCallbacks)) {
1857     if (isCGSCCPassName(FirstName, CGSCCPipelineParsingCallbacks)) {
1858       Pipeline = {{"cgscc", std::move(*Pipeline)}};
1859     } else if (isFunctionPassName(FirstName,
1860                                   FunctionPipelineParsingCallbacks)) {
1861       Pipeline = {{"function", std::move(*Pipeline)}};
1862     } else if (isLoopPassName(FirstName, LoopPipelineParsingCallbacks)) {
1863       Pipeline = {{"function", {{"loop", std::move(*Pipeline)}}}};
1864     } else {
1865       for (auto &C : TopLevelPipelineParsingCallbacks)
1866         if (C(MPM, *Pipeline, VerifyEachPass, DebugLogging))
1867           return Error::success();
1868 
1869       // Unknown pass or pipeline name!
1870       auto &InnerPipeline = Pipeline->front().InnerPipeline;
1871       return make_error<StringError>(
1872           formatv("unknown {0} name '{1}'",
1873                   (InnerPipeline.empty() ? "pass" : "pipeline"), FirstName)
1874               .str(),
1875           inconvertibleErrorCode());
1876     }
1877   }
1878 
1879   if (auto Err =
1880           parseModulePassPipeline(MPM, *Pipeline, VerifyEachPass, DebugLogging))
1881     return Err;
1882   return Error::success();
1883 }
1884 
1885 // Primary pass pipeline description parsing routine for a \c CGSCCPassManager
1886 Error PassBuilder::parsePassPipeline(CGSCCPassManager &CGPM,
1887                                      StringRef PipelineText,
1888                                      bool VerifyEachPass, bool DebugLogging) {
1889   auto Pipeline = parsePipelineText(PipelineText);
1890   if (!Pipeline || Pipeline->empty())
1891     return make_error<StringError>(
1892         formatv("invalid pipeline '{0}'", PipelineText).str(),
1893         inconvertibleErrorCode());
1894 
1895   StringRef FirstName = Pipeline->front().Name;
1896   if (!isCGSCCPassName(FirstName, CGSCCPipelineParsingCallbacks))
1897     return make_error<StringError>(
1898         formatv("unknown cgscc pass '{0}' in pipeline '{1}'", FirstName,
1899                 PipelineText)
1900             .str(),
1901         inconvertibleErrorCode());
1902 
1903   if (auto Err =
1904           parseCGSCCPassPipeline(CGPM, *Pipeline, VerifyEachPass, DebugLogging))
1905     return Err;
1906   return Error::success();
1907 }
1908 
1909 // Primary pass pipeline description parsing routine for a \c
1910 // FunctionPassManager
1911 Error PassBuilder::parsePassPipeline(FunctionPassManager &FPM,
1912                                      StringRef PipelineText,
1913                                      bool VerifyEachPass, bool DebugLogging) {
1914   auto Pipeline = parsePipelineText(PipelineText);
1915   if (!Pipeline || Pipeline->empty())
1916     return make_error<StringError>(
1917         formatv("invalid pipeline '{0}'", PipelineText).str(),
1918         inconvertibleErrorCode());
1919 
1920   StringRef FirstName = Pipeline->front().Name;
1921   if (!isFunctionPassName(FirstName, FunctionPipelineParsingCallbacks))
1922     return make_error<StringError>(
1923         formatv("unknown function pass '{0}' in pipeline '{1}'", FirstName,
1924                 PipelineText)
1925             .str(),
1926         inconvertibleErrorCode());
1927 
1928   if (auto Err = parseFunctionPassPipeline(FPM, *Pipeline, VerifyEachPass,
1929                                            DebugLogging))
1930     return Err;
1931   return Error::success();
1932 }
1933 
1934 // Primary pass pipeline description parsing routine for a \c LoopPassManager
1935 Error PassBuilder::parsePassPipeline(LoopPassManager &CGPM,
1936                                      StringRef PipelineText,
1937                                      bool VerifyEachPass, bool DebugLogging) {
1938   auto Pipeline = parsePipelineText(PipelineText);
1939   if (!Pipeline || Pipeline->empty())
1940     return make_error<StringError>(
1941         formatv("invalid pipeline '{0}'", PipelineText).str(),
1942         inconvertibleErrorCode());
1943 
1944   if (auto Err =
1945           parseLoopPassPipeline(CGPM, *Pipeline, VerifyEachPass, DebugLogging))
1946     return Err;
1947 
1948   return Error::success();
1949 }
1950 
1951 Error PassBuilder::parseAAPipeline(AAManager &AA, StringRef PipelineText) {
1952   // If the pipeline just consists of the word 'default' just replace the AA
1953   // manager with our default one.
1954   if (PipelineText == "default") {
1955     AA = buildDefaultAAPipeline();
1956     return Error::success();
1957   }
1958 
1959   while (!PipelineText.empty()) {
1960     StringRef Name;
1961     std::tie(Name, PipelineText) = PipelineText.split(',');
1962     if (!parseAAPassName(AA, Name))
1963       return make_error<StringError>(
1964           formatv("unknown alias analysis name '{0}'", Name).str(),
1965           inconvertibleErrorCode());
1966   }
1967 
1968   return Error::success();
1969 }
1970