xref: /llvm-project/llvm/unittests/Transforms/Scalar/LoopPassManagerTest.cpp (revision ee8d31c49e12a4d1fc10940a8fa644e5351239ed)
1 //===- llvm/unittest/Analysis/LoopPassManagerTest.cpp - LPM tests ---------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/Transforms/Scalar/LoopPassManager.h"
11 #include "llvm/Analysis/AliasAnalysis.h"
12 #include "llvm/Analysis/AssumptionCache.h"
13 #include "llvm/Analysis/ScalarEvolution.h"
14 #include "llvm/Analysis/TargetLibraryInfo.h"
15 #include "llvm/Analysis/TargetTransformInfo.h"
16 #include "llvm/AsmParser/Parser.h"
17 #include "llvm/IR/Dominators.h"
18 #include "llvm/IR/Function.h"
19 #include "llvm/IR/LLVMContext.h"
20 #include "llvm/IR/Module.h"
21 #include "llvm/IR/PassManager.h"
22 #include "llvm/Support/SourceMgr.h"
23 
24 // Workaround for the gcc 6.1 bug PR80916.
25 #if defined(__GNUC__) && __GNUC__ > 5
26 #  pragma GCC diagnostic push
27 #  pragma GCC diagnostic ignored "-Wunused-function"
28 #endif
29 
30 #include "gmock/gmock.h"
31 #include "gtest/gtest.h"
32 
33 #if defined(__GNUC__) && __GNUC__ > 5
34 #  pragma GCC diagnostic pop
35 #endif
36 
37 using namespace llvm;
38 
39 namespace {
40 
41 using testing::DoDefault;
42 using testing::Return;
43 using testing::Expectation;
44 using testing::Invoke;
45 using testing::InvokeWithoutArgs;
46 using testing::_;
47 
48 template <typename DerivedT, typename IRUnitT,
49           typename AnalysisManagerT = AnalysisManager<IRUnitT>,
50           typename... ExtraArgTs>
51 class MockAnalysisHandleBase {
52 public:
53   class Analysis : public AnalysisInfoMixin<Analysis> {
54     friend AnalysisInfoMixin<Analysis>;
55     friend MockAnalysisHandleBase;
56     static AnalysisKey Key;
57 
58     DerivedT *Handle;
59 
60     Analysis(DerivedT &Handle) : Handle(&Handle) {
61       static_assert(std::is_base_of<MockAnalysisHandleBase, DerivedT>::value,
62                     "Must pass the derived type to this template!");
63     }
64 
65   public:
66     class Result {
67       friend MockAnalysisHandleBase;
68 
69       DerivedT *Handle;
70 
71       Result(DerivedT &Handle) : Handle(&Handle) {}
72 
73     public:
74       // Forward invalidation events to the mock handle.
75       bool invalidate(IRUnitT &IR, const PreservedAnalyses &PA,
76                       typename AnalysisManagerT::Invalidator &Inv) {
77         return Handle->invalidate(IR, PA, Inv);
78       }
79     };
80 
81     Result run(IRUnitT &IR, AnalysisManagerT &AM, ExtraArgTs... ExtraArgs) {
82       return Handle->run(IR, AM, ExtraArgs...);
83     }
84   };
85 
86   Analysis getAnalysis() { return Analysis(static_cast<DerivedT &>(*this)); }
87   typename Analysis::Result getResult() {
88     return typename Analysis::Result(static_cast<DerivedT &>(*this));
89   }
90 
91 protected:
92   // FIXME: MSVC seems unable to handle a lambda argument to Invoke from within
93   // the template, so we use a boring static function.
94   static bool invalidateCallback(IRUnitT &IR, const PreservedAnalyses &PA,
95                                  typename AnalysisManagerT::Invalidator &Inv) {
96     auto PAC = PA.template getChecker<Analysis>();
97     return !PAC.preserved() &&
98            !PAC.template preservedSet<AllAnalysesOn<IRUnitT>>();
99   }
100 
101   /// Derived classes should call this in their constructor to set up default
102   /// mock actions. (We can't do this in our constructor because this has to
103   /// run after the DerivedT is constructed.)
104   void setDefaults() {
105     ON_CALL(static_cast<DerivedT &>(*this),
106             run(_, _, testing::Matcher<ExtraArgTs>(_)...))
107         .WillByDefault(Return(this->getResult()));
108     ON_CALL(static_cast<DerivedT &>(*this), invalidate(_, _, _))
109         .WillByDefault(Invoke(&invalidateCallback));
110   }
111 };
112 
113 template <typename DerivedT, typename IRUnitT, typename AnalysisManagerT,
114           typename... ExtraArgTs>
115 AnalysisKey MockAnalysisHandleBase<DerivedT, IRUnitT, AnalysisManagerT,
116                                    ExtraArgTs...>::Analysis::Key;
117 
118 /// Mock handle for loop analyses.
119 ///
120 /// This is provided as a template accepting an (optional) integer. Because
121 /// analyses are identified and queried by type, this allows constructing
122 /// multiple handles with distinctly typed nested 'Analysis' types that can be
123 /// registered and queried. If you want to register multiple loop analysis
124 /// passes, you'll need to instantiate this type with different values for I.
125 /// For example:
126 ///
127 ///   MockLoopAnalysisHandleTemplate<0> h0;
128 ///   MockLoopAnalysisHandleTemplate<1> h1;
129 ///   typedef decltype(h0)::Analysis Analysis0;
130 ///   typedef decltype(h1)::Analysis Analysis1;
131 template <size_t I = static_cast<size_t>(-1)>
132 struct MockLoopAnalysisHandleTemplate
133     : MockAnalysisHandleBase<MockLoopAnalysisHandleTemplate<I>, Loop,
134                              LoopAnalysisManager,
135                              LoopStandardAnalysisResults &> {
136   typedef typename MockLoopAnalysisHandleTemplate::Analysis Analysis;
137 
138   MOCK_METHOD3_T(run, typename Analysis::Result(Loop &, LoopAnalysisManager &,
139                                                 LoopStandardAnalysisResults &));
140 
141   MOCK_METHOD3_T(invalidate, bool(Loop &, const PreservedAnalyses &,
142                                   LoopAnalysisManager::Invalidator &));
143 
144   MockLoopAnalysisHandleTemplate() { this->setDefaults(); }
145 };
146 
147 typedef MockLoopAnalysisHandleTemplate<> MockLoopAnalysisHandle;
148 
149 struct MockFunctionAnalysisHandle
150     : MockAnalysisHandleBase<MockFunctionAnalysisHandle, Function> {
151   MOCK_METHOD2(run, Analysis::Result(Function &, FunctionAnalysisManager &));
152 
153   MOCK_METHOD3(invalidate, bool(Function &, const PreservedAnalyses &,
154                                 FunctionAnalysisManager::Invalidator &));
155 
156   MockFunctionAnalysisHandle() { setDefaults(); }
157 };
158 
159 template <typename DerivedT, typename IRUnitT,
160           typename AnalysisManagerT = AnalysisManager<IRUnitT>,
161           typename... ExtraArgTs>
162 class MockPassHandleBase {
163 public:
164   class Pass : public PassInfoMixin<Pass> {
165     friend MockPassHandleBase;
166 
167     DerivedT *Handle;
168 
169     Pass(DerivedT &Handle) : Handle(&Handle) {
170       static_assert(std::is_base_of<MockPassHandleBase, DerivedT>::value,
171                     "Must pass the derived type to this template!");
172     }
173 
174   public:
175     PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM,
176                           ExtraArgTs... ExtraArgs) {
177       return Handle->run(IR, AM, ExtraArgs...);
178     }
179   };
180 
181   Pass getPass() { return Pass(static_cast<DerivedT &>(*this)); }
182 
183 protected:
184   /// Derived classes should call this in their constructor to set up default
185   /// mock actions. (We can't do this in our constructor because this has to
186   /// run after the DerivedT is constructed.)
187   void setDefaults() {
188     ON_CALL(static_cast<DerivedT &>(*this),
189             run(_, _, testing::Matcher<ExtraArgTs>(_)...))
190         .WillByDefault(Return(PreservedAnalyses::all()));
191   }
192 };
193 
194 struct MockLoopPassHandle
195     : MockPassHandleBase<MockLoopPassHandle, Loop, LoopAnalysisManager,
196                          LoopStandardAnalysisResults &, LPMUpdater &> {
197   MOCK_METHOD4(run,
198                PreservedAnalyses(Loop &, LoopAnalysisManager &,
199                                  LoopStandardAnalysisResults &, LPMUpdater &));
200   MockLoopPassHandle() { setDefaults(); }
201 };
202 
203 struct MockFunctionPassHandle
204     : MockPassHandleBase<MockFunctionPassHandle, Function> {
205   MOCK_METHOD2(run, PreservedAnalyses(Function &, FunctionAnalysisManager &));
206 
207   MockFunctionPassHandle() { setDefaults(); }
208 };
209 
210 struct MockModulePassHandle : MockPassHandleBase<MockModulePassHandle, Module> {
211   MOCK_METHOD2(run, PreservedAnalyses(Module &, ModuleAnalysisManager &));
212 
213   MockModulePassHandle() { setDefaults(); }
214 };
215 
216 /// Define a custom matcher for objects which support a 'getName' method
217 /// returning a StringRef.
218 ///
219 /// LLVM often has IR objects or analysis objects which expose a StringRef name
220 /// and in tests it is convenient to match these by name for readability. This
221 /// matcher supports any type exposing a getName() method of this form.
222 ///
223 /// It should be used as:
224 ///
225 ///   HasName("my_function")
226 ///
227 /// No namespace or other qualification is required.
228 MATCHER_P(HasName, Name, "") {
229   // The matcher's name and argument are printed in the case of failure, but we
230   // also want to print out the name of the argument. This uses an implicitly
231   // avaiable std::ostream, so we have to construct a std::string.
232   *result_listener << "has name '" << arg.getName().str() << "'";
233   return Name == arg.getName();
234 }
235 
236 std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
237   SMDiagnostic Err;
238   return parseAssemblyString(IR, Err, C);
239 }
240 
241 class LoopPassManagerTest : public ::testing::Test {
242 protected:
243   LLVMContext Context;
244   std::unique_ptr<Module> M;
245 
246   LoopAnalysisManager LAM;
247   FunctionAnalysisManager FAM;
248   ModuleAnalysisManager MAM;
249 
250   MockLoopAnalysisHandle MLAHandle;
251   MockLoopPassHandle MLPHandle;
252   MockFunctionPassHandle MFPHandle;
253   MockModulePassHandle MMPHandle;
254 
255   static PreservedAnalyses
256   getLoopAnalysisResult(Loop &L, LoopAnalysisManager &AM,
257                         LoopStandardAnalysisResults &AR, LPMUpdater &) {
258     (void)AM.getResult<MockLoopAnalysisHandle::Analysis>(L, AR);
259     return PreservedAnalyses::all();
260   };
261 
262 public:
263   LoopPassManagerTest()
264       : M(parseIR(Context,
265                   "define void @f(i1* %ptr) {\n"
266                   "entry:\n"
267                   "  br label %loop.0\n"
268                   "loop.0:\n"
269                   "  %cond.0 = load volatile i1, i1* %ptr\n"
270                   "  br i1 %cond.0, label %loop.0.0.ph, label %end\n"
271                   "loop.0.0.ph:\n"
272                   "  br label %loop.0.0\n"
273                   "loop.0.0:\n"
274                   "  %cond.0.0 = load volatile i1, i1* %ptr\n"
275                   "  br i1 %cond.0.0, label %loop.0.0, label %loop.0.1.ph\n"
276                   "loop.0.1.ph:\n"
277                   "  br label %loop.0.1\n"
278                   "loop.0.1:\n"
279                   "  %cond.0.1 = load volatile i1, i1* %ptr\n"
280                   "  br i1 %cond.0.1, label %loop.0.1, label %loop.0.latch\n"
281                   "loop.0.latch:\n"
282                   "  br label %loop.0\n"
283                   "end:\n"
284                   "  ret void\n"
285                   "}\n"
286                   "\n"
287                   "define void @g(i1* %ptr) {\n"
288                   "entry:\n"
289                   "  br label %loop.g.0\n"
290                   "loop.g.0:\n"
291                   "  %cond.0 = load volatile i1, i1* %ptr\n"
292                   "  br i1 %cond.0, label %loop.g.0, label %end\n"
293                   "end:\n"
294                   "  ret void\n"
295                   "}\n")),
296         LAM(true), FAM(true), MAM(true) {
297     // Register our mock analysis.
298     LAM.registerPass([&] { return MLAHandle.getAnalysis(); });
299 
300     // We need DominatorTreeAnalysis for LoopAnalysis.
301     FAM.registerPass([&] { return DominatorTreeAnalysis(); });
302     FAM.registerPass([&] { return LoopAnalysis(); });
303     // We also allow loop passes to assume a set of other analyses and so need
304     // those.
305     FAM.registerPass([&] { return AAManager(); });
306     FAM.registerPass([&] { return AssumptionAnalysis(); });
307     FAM.registerPass([&] { return ScalarEvolutionAnalysis(); });
308     FAM.registerPass([&] { return TargetLibraryAnalysis(); });
309     FAM.registerPass([&] { return TargetIRAnalysis(); });
310 
311     // Register required pass instrumentation analysis.
312     LAM.registerPass([&] { return PassInstrumentationAnalysis(); });
313     FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
314     MAM.registerPass([&] { return PassInstrumentationAnalysis(); });
315 
316     // Cross-register proxies.
317     LAM.registerPass([&] { return FunctionAnalysisManagerLoopProxy(FAM); });
318     FAM.registerPass([&] { return LoopAnalysisManagerFunctionProxy(LAM); });
319     FAM.registerPass([&] { return ModuleAnalysisManagerFunctionProxy(MAM); });
320     MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(FAM); });
321   }
322 };
323 
324 TEST_F(LoopPassManagerTest, Basic) {
325   ModulePassManager MPM(true);
326   ::testing::InSequence MakeExpectationsSequenced;
327 
328   // First we just visit all the loops in all the functions and get their
329   // analysis results. This will run the analysis a total of four times,
330   // once for each loop.
331   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
332       .WillOnce(Invoke(getLoopAnalysisResult));
333   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
334   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
335       .WillOnce(Invoke(getLoopAnalysisResult));
336   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
337   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
338       .WillOnce(Invoke(getLoopAnalysisResult));
339   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
340   EXPECT_CALL(MLPHandle, run(HasName("loop.g.0"), _, _, _))
341       .WillOnce(Invoke(getLoopAnalysisResult));
342   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
343   // Wire the loop pass through pass managers into the module pipeline.
344   {
345     LoopPassManager LPM(true);
346     LPM.addPass(MLPHandle.getPass());
347     FunctionPassManager FPM(true);
348     FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
349     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
350   }
351 
352   // Next we run two passes over the loops. The first one invalidates the
353   // analyses for one loop, the second ones try to get the analysis results.
354   // This should force only one analysis to re-run within the loop PM, but will
355   // also invalidate everything after the loop pass manager finishes.
356   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
357       .WillOnce(DoDefault())
358       .WillOnce(Invoke(getLoopAnalysisResult));
359   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
360       .WillOnce(InvokeWithoutArgs([] { return PreservedAnalyses::none(); }))
361       .WillOnce(Invoke(getLoopAnalysisResult));
362   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
363   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
364       .WillOnce(DoDefault())
365       .WillOnce(Invoke(getLoopAnalysisResult));
366   EXPECT_CALL(MLPHandle, run(HasName("loop.g.0"), _, _, _))
367       .WillOnce(DoDefault())
368       .WillOnce(Invoke(getLoopAnalysisResult));
369   // Wire two loop pass runs into the module pipeline.
370   {
371     LoopPassManager LPM(true);
372     LPM.addPass(MLPHandle.getPass());
373     LPM.addPass(MLPHandle.getPass());
374     FunctionPassManager FPM(true);
375     FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
376     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
377   }
378 
379   // And now run the pipeline across the module.
380   MPM.run(*M, MAM);
381 }
382 
383 TEST_F(LoopPassManagerTest, FunctionPassInvalidationOfLoopAnalyses) {
384   ModulePassManager MPM(true);
385   FunctionPassManager FPM(true);
386   // We process each function completely in sequence.
387   ::testing::Sequence FSequence, GSequence;
388 
389   // First, force the analysis result to be computed for each loop.
390   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _))
391       .InSequence(FSequence)
392       .WillOnce(DoDefault());
393   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _))
394       .InSequence(FSequence)
395       .WillOnce(DoDefault());
396   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _))
397       .InSequence(FSequence)
398       .WillOnce(DoDefault());
399   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _))
400       .InSequence(GSequence)
401       .WillOnce(DoDefault());
402   FPM.addPass(createFunctionToLoopPassAdaptor(
403       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
404 
405   // No need to re-run if we require again from a fresh loop pass manager.
406   FPM.addPass(createFunctionToLoopPassAdaptor(
407       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
408 
409   // For 'f', preserve most things but not the specific loop analyses.
410   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
411       .InSequence(FSequence)
412       .WillOnce(Return(getLoopPassPreservedAnalyses()));
413   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.0"), _, _))
414       .InSequence(FSequence)
415       .WillOnce(DoDefault());
416   // On one loop, skip the invalidation (as though we did an internal update).
417   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.1"), _, _))
418       .InSequence(FSequence)
419       .WillOnce(Return(false));
420   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0"), _, _))
421       .InSequence(FSequence)
422       .WillOnce(DoDefault());
423   // Now two loops still have to be recomputed.
424   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _))
425       .InSequence(FSequence)
426       .WillOnce(DoDefault());
427   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _))
428       .InSequence(FSequence)
429       .WillOnce(DoDefault());
430   // Preserve things in the second function to ensure invalidation remains
431   // isolated to one function.
432   EXPECT_CALL(MFPHandle, run(HasName("g"), _))
433       .InSequence(GSequence)
434       .WillOnce(DoDefault());
435   FPM.addPass(MFPHandle.getPass());
436   FPM.addPass(createFunctionToLoopPassAdaptor(
437       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
438 
439   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
440       .InSequence(FSequence)
441       .WillOnce(DoDefault());
442   // For 'g', fail to preserve anything, causing the loops themselves to be
443   // cleared. We don't get an invalidation event here as the loop is gone, but
444   // we should still have to recompute the analysis.
445   EXPECT_CALL(MFPHandle, run(HasName("g"), _))
446       .InSequence(GSequence)
447       .WillOnce(Return(PreservedAnalyses::none()));
448   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _))
449       .InSequence(GSequence)
450       .WillOnce(DoDefault());
451   FPM.addPass(MFPHandle.getPass());
452   FPM.addPass(createFunctionToLoopPassAdaptor(
453       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
454 
455   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
456 
457   // Verify with a separate function pass run that we didn't mess up 'f's
458   // cache. No analysis runs should be necessary here.
459   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
460       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
461 
462   MPM.run(*M, MAM);
463 }
464 
465 TEST_F(LoopPassManagerTest, ModulePassInvalidationOfLoopAnalyses) {
466   ModulePassManager MPM(true);
467   ::testing::InSequence MakeExpectationsSequenced;
468 
469   // First, force the analysis result to be computed for each loop.
470   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
471   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
472   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
473   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
474   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
475       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
476 
477   // Walking all the way out and all the way back in doesn't re-run the
478   // analysis.
479   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
480       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
481 
482   // But a module pass that doesn't preserve the actual mock loop analysis
483   // invalidates all the way down and forces recomputing.
484   EXPECT_CALL(MMPHandle, run(_, _)).WillOnce(InvokeWithoutArgs([] {
485     auto PA = getLoopPassPreservedAnalyses();
486     PA.preserve<FunctionAnalysisManagerModuleProxy>();
487     return PA;
488   }));
489   // All the loop analyses from both functions get invalidated before we
490   // recompute anything.
491   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.0"), _, _));
492   // On one loop, again skip the invalidation (as though we did an internal
493   // update).
494   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.1"), _, _))
495       .WillOnce(Return(false));
496   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0"), _, _));
497   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.g.0"), _, _));
498   // Now all but one of the loops gets re-analyzed.
499   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
500   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
501   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
502   MPM.addPass(MMPHandle.getPass());
503   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
504       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
505 
506   // Verify that the cached values persist.
507   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
508       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
509 
510   // Now we fail to preserve the loop analysis and observe that the loop
511   // analyses are cleared (so no invalidation event) as the loops themselves
512   // are no longer valid.
513   EXPECT_CALL(MMPHandle, run(_, _)).WillOnce(InvokeWithoutArgs([] {
514     auto PA = PreservedAnalyses::none();
515     PA.preserve<FunctionAnalysisManagerModuleProxy>();
516     return PA;
517   }));
518   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
519   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
520   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
521   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
522   MPM.addPass(MMPHandle.getPass());
523   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
524       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
525 
526   // Verify that the cached values persist.
527   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
528       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
529 
530   // Next, check that even if we preserve everything within the function itelf,
531   // if the function's module pass proxy isn't preserved and the potential set
532   // of functions changes, the clear reaches the loop analyses as well. This
533   // will again trigger re-runs but not invalidation events.
534   EXPECT_CALL(MMPHandle, run(_, _)).WillOnce(InvokeWithoutArgs([] {
535     auto PA = PreservedAnalyses::none();
536     PA.preserveSet<AllAnalysesOn<Function>>();
537     PA.preserveSet<AllAnalysesOn<Loop>>();
538     return PA;
539   }));
540   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
541   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
542   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
543   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
544   MPM.addPass(MMPHandle.getPass());
545   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
546       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
547 
548   MPM.run(*M, MAM);
549 }
550 
551 // Test that if any of the bundled analyses provided in the LPM's signature
552 // become invalid, the analysis proxy itself becomes invalid and we clear all
553 // loop analysis results.
554 TEST_F(LoopPassManagerTest, InvalidationOfBundledAnalyses) {
555   ModulePassManager MPM(true);
556   FunctionPassManager FPM(true);
557   ::testing::InSequence MakeExpectationsSequenced;
558 
559   // First, force the analysis result to be computed for each loop.
560   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
561   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
562   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
563   FPM.addPass(createFunctionToLoopPassAdaptor(
564       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
565 
566   // No need to re-run if we require again from a fresh loop pass manager.
567   FPM.addPass(createFunctionToLoopPassAdaptor(
568       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
569 
570   // Preserving everything but the loop analyses themselves results in
571   // invalidation and running.
572   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
573       .WillOnce(Return(getLoopPassPreservedAnalyses()));
574   EXPECT_CALL(MLAHandle, invalidate(_, _, _)).Times(3);
575   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
576   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
577   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
578   FPM.addPass(MFPHandle.getPass());
579   FPM.addPass(createFunctionToLoopPassAdaptor(
580       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
581 
582   // The rest don't invalidate analyses, they only trigger re-runs because we
583   // clear the cache completely.
584   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
585     auto PA = PreservedAnalyses::none();
586     // Not preserving `AAManager`.
587     PA.preserve<DominatorTreeAnalysis>();
588     PA.preserve<LoopAnalysis>();
589     PA.preserve<LoopAnalysisManagerFunctionProxy>();
590     PA.preserve<ScalarEvolutionAnalysis>();
591     return PA;
592   }));
593   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
594   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
595   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
596   FPM.addPass(MFPHandle.getPass());
597   FPM.addPass(createFunctionToLoopPassAdaptor(
598       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
599 
600   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
601     auto PA = PreservedAnalyses::none();
602     PA.preserve<AAManager>();
603     // Not preserving `DominatorTreeAnalysis`.
604     PA.preserve<LoopAnalysis>();
605     PA.preserve<LoopAnalysisManagerFunctionProxy>();
606     PA.preserve<ScalarEvolutionAnalysis>();
607     return PA;
608   }));
609   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
610   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
611   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
612   FPM.addPass(MFPHandle.getPass());
613   FPM.addPass(createFunctionToLoopPassAdaptor(
614       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
615 
616   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
617     auto PA = PreservedAnalyses::none();
618     PA.preserve<AAManager>();
619     PA.preserve<DominatorTreeAnalysis>();
620     // Not preserving the `LoopAnalysis`.
621     PA.preserve<LoopAnalysisManagerFunctionProxy>();
622     PA.preserve<ScalarEvolutionAnalysis>();
623     return PA;
624   }));
625   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
626   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
627   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
628   FPM.addPass(MFPHandle.getPass());
629   FPM.addPass(createFunctionToLoopPassAdaptor(
630       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
631 
632   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
633     auto PA = PreservedAnalyses::none();
634     PA.preserve<AAManager>();
635     PA.preserve<DominatorTreeAnalysis>();
636     PA.preserve<LoopAnalysis>();
637     // Not preserving the `LoopAnalysisManagerFunctionProxy`.
638     PA.preserve<ScalarEvolutionAnalysis>();
639     return PA;
640   }));
641   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
642   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
643   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
644   FPM.addPass(MFPHandle.getPass());
645   FPM.addPass(createFunctionToLoopPassAdaptor(
646       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
647 
648   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
649     auto PA = PreservedAnalyses::none();
650     PA.preserve<AAManager>();
651     PA.preserve<DominatorTreeAnalysis>();
652     PA.preserve<LoopAnalysis>();
653     PA.preserve<LoopAnalysisManagerFunctionProxy>();
654     // Not preserving `ScalarEvolutionAnalysis`.
655     return PA;
656   }));
657   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
658   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
659   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
660   FPM.addPass(MFPHandle.getPass());
661   FPM.addPass(createFunctionToLoopPassAdaptor(
662       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
663 
664   // After all the churn on 'f', we'll compute the loop analysis results for
665   // 'g' once with a requires pass and then run our mock pass over g a bunch
666   // but just get cached results each time.
667   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
668   EXPECT_CALL(MFPHandle, run(HasName("g"), _)).Times(6);
669 
670   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
671   MPM.run(*M, MAM);
672 }
673 
674 TEST_F(LoopPassManagerTest, IndirectInvalidation) {
675   // We need two distinct analysis types and handles.
676   enum { A, B };
677   MockLoopAnalysisHandleTemplate<A> MLAHandleA;
678   MockLoopAnalysisHandleTemplate<B> MLAHandleB;
679   LAM.registerPass([&] { return MLAHandleA.getAnalysis(); });
680   LAM.registerPass([&] { return MLAHandleB.getAnalysis(); });
681   typedef decltype(MLAHandleA)::Analysis AnalysisA;
682   typedef decltype(MLAHandleB)::Analysis AnalysisB;
683 
684   // Set up AnalysisA to depend on our AnalysisB. For testing purposes we just
685   // need to get the AnalysisB results in AnalysisA's run method and check if
686   // AnalysisB gets invalidated in AnalysisA's invalidate method.
687   ON_CALL(MLAHandleA, run(_, _, _))
688       .WillByDefault(Invoke([&](Loop &L, LoopAnalysisManager &AM,
689                                 LoopStandardAnalysisResults &AR) {
690         (void)AM.getResult<AnalysisB>(L, AR);
691         return MLAHandleA.getResult();
692       }));
693   ON_CALL(MLAHandleA, invalidate(_, _, _))
694       .WillByDefault(Invoke([](Loop &L, const PreservedAnalyses &PA,
695                                LoopAnalysisManager::Invalidator &Inv) {
696         auto PAC = PA.getChecker<AnalysisA>();
697         return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Loop>>()) ||
698                Inv.invalidate<AnalysisB>(L, PA);
699       }));
700 
701   ::testing::InSequence MakeExpectationsSequenced;
702 
703   // Compute the analyses across all of 'f' first.
704   EXPECT_CALL(MLAHandleA, run(HasName("loop.0.0"), _, _));
705   EXPECT_CALL(MLAHandleB, run(HasName("loop.0.0"), _, _));
706   EXPECT_CALL(MLAHandleA, run(HasName("loop.0.1"), _, _));
707   EXPECT_CALL(MLAHandleB, run(HasName("loop.0.1"), _, _));
708   EXPECT_CALL(MLAHandleA, run(HasName("loop.0"), _, _));
709   EXPECT_CALL(MLAHandleB, run(HasName("loop.0"), _, _));
710 
711   // Now we invalidate AnalysisB (but not AnalysisA) for one of the loops and
712   // preserve everything for the rest. This in turn triggers that one loop to
713   // recompute both AnalysisB *and* AnalysisA if indirect invalidation is
714   // working.
715   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
716       .WillOnce(InvokeWithoutArgs([] {
717         auto PA = getLoopPassPreservedAnalyses();
718         // Specifically preserve AnalysisA so that it would survive if it
719         // didn't depend on AnalysisB.
720         PA.preserve<AnalysisA>();
721         return PA;
722       }));
723   // It happens that AnalysisB is invalidated first. That shouldn't matter
724   // though, and we should still call AnalysisA's invalidation.
725   EXPECT_CALL(MLAHandleB, invalidate(HasName("loop.0.0"), _, _));
726   EXPECT_CALL(MLAHandleA, invalidate(HasName("loop.0.0"), _, _));
727   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
728       .WillOnce(Invoke([](Loop &L, LoopAnalysisManager &AM,
729                           LoopStandardAnalysisResults &AR, LPMUpdater &) {
730         (void)AM.getResult<AnalysisA>(L, AR);
731         return PreservedAnalyses::all();
732       }));
733   EXPECT_CALL(MLAHandleA, run(HasName("loop.0.0"), _, _));
734   EXPECT_CALL(MLAHandleB, run(HasName("loop.0.0"), _, _));
735   // The rest of the loops should run and get cached results.
736   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
737       .Times(2)
738       .WillRepeatedly(Invoke([](Loop &L, LoopAnalysisManager &AM,
739                                 LoopStandardAnalysisResults &AR, LPMUpdater &) {
740         (void)AM.getResult<AnalysisA>(L, AR);
741         return PreservedAnalyses::all();
742       }));
743   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
744       .Times(2)
745       .WillRepeatedly(Invoke([](Loop &L, LoopAnalysisManager &AM,
746                                 LoopStandardAnalysisResults &AR, LPMUpdater &) {
747         (void)AM.getResult<AnalysisA>(L, AR);
748         return PreservedAnalyses::all();
749       }));
750 
751   // The run over 'g' should be boring, with us just computing the analyses once
752   // up front and then running loop passes and getting cached results.
753   EXPECT_CALL(MLAHandleA, run(HasName("loop.g.0"), _, _));
754   EXPECT_CALL(MLAHandleB, run(HasName("loop.g.0"), _, _));
755   EXPECT_CALL(MLPHandle, run(HasName("loop.g.0"), _, _, _))
756       .Times(2)
757       .WillRepeatedly(Invoke([](Loop &L, LoopAnalysisManager &AM,
758                                 LoopStandardAnalysisResults &AR, LPMUpdater &) {
759         (void)AM.getResult<AnalysisA>(L, AR);
760         return PreservedAnalyses::all();
761       }));
762 
763   // Build the pipeline and run it.
764   ModulePassManager MPM(true);
765   FunctionPassManager FPM(true);
766   FPM.addPass(
767       createFunctionToLoopPassAdaptor(RequireAnalysisLoopPass<AnalysisA>()));
768   LoopPassManager LPM(true);
769   LPM.addPass(MLPHandle.getPass());
770   LPM.addPass(MLPHandle.getPass());
771   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
772   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
773   MPM.run(*M, MAM);
774 }
775 
776 TEST_F(LoopPassManagerTest, IndirectOuterPassInvalidation) {
777   typedef decltype(MLAHandle)::Analysis LoopAnalysis;
778 
779   MockFunctionAnalysisHandle MFAHandle;
780   FAM.registerPass([&] { return MFAHandle.getAnalysis(); });
781   typedef decltype(MFAHandle)::Analysis FunctionAnalysis;
782 
783   // Set up the loop analysis to depend on both the function and module
784   // analysis.
785   ON_CALL(MLAHandle, run(_, _, _))
786       .WillByDefault(Invoke([&](Loop &L, LoopAnalysisManager &AM,
787                                 LoopStandardAnalysisResults &AR) {
788         auto &FAMP = AM.getResult<FunctionAnalysisManagerLoopProxy>(L, AR);
789         auto &FAM = FAMP.getManager();
790         Function &F = *L.getHeader()->getParent();
791         if (FAM.getCachedResult<FunctionAnalysis>(F))
792           FAMP.registerOuterAnalysisInvalidation<FunctionAnalysis,
793                                                  LoopAnalysis>();
794         return MLAHandle.getResult();
795       }));
796 
797   ::testing::InSequence MakeExpectationsSequenced;
798 
799   // Compute the analyses across all of 'f' first.
800   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
801       .WillOnce(Invoke([](Function &F, FunctionAnalysisManager &AM) {
802         // Force the computing of the function analysis so it is available in
803         // this function.
804         (void)AM.getResult<FunctionAnalysis>(F);
805         return PreservedAnalyses::all();
806       }));
807   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
808   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
809   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
810 
811   // Now invalidate the function analysis but preserve the loop analyses.
812   // This should trigger immediate invalidation of the loop analyses, despite
813   // the fact that they were preserved.
814   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
815     auto PA = getLoopPassPreservedAnalyses();
816     PA.preserveSet<AllAnalysesOn<Loop>>();
817     return PA;
818   }));
819   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.0"), _, _));
820   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.1"), _, _));
821   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0"), _, _));
822 
823   // And re-running a requires pass recomputes them.
824   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
825   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
826   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
827 
828   // When we run over 'g' we don't populate the cache with the function
829   // analysis.
830   EXPECT_CALL(MFPHandle, run(HasName("g"), _))
831       .WillOnce(Return(PreservedAnalyses::all()));
832   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
833 
834   // Which means that no extra invalidation occurs and cached values are used.
835   EXPECT_CALL(MFPHandle, run(HasName("g"), _)).WillOnce(InvokeWithoutArgs([] {
836     auto PA = getLoopPassPreservedAnalyses();
837     PA.preserveSet<AllAnalysesOn<Loop>>();
838     return PA;
839   }));
840 
841   // Build the pipeline and run it.
842   ModulePassManager MPM(true);
843   FunctionPassManager FPM(true);
844   FPM.addPass(MFPHandle.getPass());
845   FPM.addPass(
846       createFunctionToLoopPassAdaptor(RequireAnalysisLoopPass<LoopAnalysis>()));
847   FPM.addPass(MFPHandle.getPass());
848   FPM.addPass(
849       createFunctionToLoopPassAdaptor(RequireAnalysisLoopPass<LoopAnalysis>()));
850   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
851   MPM.run(*M, MAM);
852 }
853 
854 TEST_F(LoopPassManagerTest, LoopChildInsertion) {
855   // Super boring module with three loops in a single loop nest.
856   M = parseIR(Context, "define void @f(i1* %ptr) {\n"
857                        "entry:\n"
858                        "  br label %loop.0\n"
859                        "loop.0:\n"
860                        "  %cond.0 = load volatile i1, i1* %ptr\n"
861                        "  br i1 %cond.0, label %loop.0.0.ph, label %end\n"
862                        "loop.0.0.ph:\n"
863                        "  br label %loop.0.0\n"
864                        "loop.0.0:\n"
865                        "  %cond.0.0 = load volatile i1, i1* %ptr\n"
866                        "  br i1 %cond.0.0, label %loop.0.0, label %loop.0.1.ph\n"
867                        "loop.0.1.ph:\n"
868                        "  br label %loop.0.1\n"
869                        "loop.0.1:\n"
870                        "  %cond.0.1 = load volatile i1, i1* %ptr\n"
871                        "  br i1 %cond.0.1, label %loop.0.1, label %loop.0.2.ph\n"
872                        "loop.0.2.ph:\n"
873                        "  br label %loop.0.2\n"
874                        "loop.0.2:\n"
875                        "  %cond.0.2 = load volatile i1, i1* %ptr\n"
876                        "  br i1 %cond.0.2, label %loop.0.2, label %loop.0.latch\n"
877                        "loop.0.latch:\n"
878                        "  br label %loop.0\n"
879                        "end:\n"
880                        "  ret void\n"
881                        "}\n");
882 
883   // Build up variables referring into the IR so we can rewrite it below
884   // easily.
885   Function &F = *M->begin();
886   ASSERT_THAT(F, HasName("f"));
887   Argument &Ptr = *F.arg_begin();
888   auto BBI = F.begin();
889   BasicBlock &EntryBB = *BBI++;
890   ASSERT_THAT(EntryBB, HasName("entry"));
891   BasicBlock &Loop0BB = *BBI++;
892   ASSERT_THAT(Loop0BB, HasName("loop.0"));
893   BasicBlock &Loop00PHBB = *BBI++;
894   ASSERT_THAT(Loop00PHBB, HasName("loop.0.0.ph"));
895   BasicBlock &Loop00BB = *BBI++;
896   ASSERT_THAT(Loop00BB, HasName("loop.0.0"));
897   BasicBlock &Loop01PHBB = *BBI++;
898   ASSERT_THAT(Loop01PHBB, HasName("loop.0.1.ph"));
899   BasicBlock &Loop01BB = *BBI++;
900   ASSERT_THAT(Loop01BB, HasName("loop.0.1"));
901   BasicBlock &Loop02PHBB = *BBI++;
902   ASSERT_THAT(Loop02PHBB, HasName("loop.0.2.ph"));
903   BasicBlock &Loop02BB = *BBI++;
904   ASSERT_THAT(Loop02BB, HasName("loop.0.2"));
905   BasicBlock &Loop0LatchBB = *BBI++;
906   ASSERT_THAT(Loop0LatchBB, HasName("loop.0.latch"));
907   BasicBlock &EndBB = *BBI++;
908   ASSERT_THAT(EndBB, HasName("end"));
909   ASSERT_THAT(BBI, F.end());
910   auto CreateCondBr = [&](BasicBlock *TrueBB, BasicBlock *FalseBB,
911                           const char *Name, BasicBlock *BB) {
912     auto *Cond = new LoadInst(&Ptr, Name, /*isVolatile*/ true, BB);
913     BranchInst::Create(TrueBB, FalseBB, Cond, BB);
914   };
915 
916   // Build the pass managers and register our pipeline. We build a single loop
917   // pass pipeline consisting of three mock pass runs over each loop. After
918   // this we run both domtree and loop verification passes to make sure that
919   // the IR remained valid during our mutations.
920   ModulePassManager MPM(true);
921   FunctionPassManager FPM(true);
922   LoopPassManager LPM(true);
923   LPM.addPass(MLPHandle.getPass());
924   LPM.addPass(MLPHandle.getPass());
925   LPM.addPass(MLPHandle.getPass());
926   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
927   FPM.addPass(DominatorTreeVerifierPass());
928   FPM.addPass(LoopVerifierPass());
929   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
930 
931   // All the visit orders are deterministic, so we use simple fully order
932   // expectations.
933   ::testing::InSequence MakeExpectationsSequenced;
934 
935   // We run loop passes three times over each of the loops.
936   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
937       .WillOnce(Invoke(getLoopAnalysisResult));
938   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
939   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
940       .Times(2)
941       .WillRepeatedly(Invoke(getLoopAnalysisResult));
942 
943   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
944       .WillOnce(Invoke(getLoopAnalysisResult));
945   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
946 
947   // When running over the middle loop, the second run inserts two new child
948   // loops, inserting them and itself into the worklist.
949   BasicBlock *NewLoop010BB, *NewLoop01LatchBB;
950   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
951       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
952                            LoopStandardAnalysisResults &AR,
953                            LPMUpdater &Updater) {
954         auto *NewLoop = AR.LI.AllocateLoop();
955         L.addChildLoop(NewLoop);
956         auto *NewLoop010PHBB =
957             BasicBlock::Create(Context, "loop.0.1.0.ph", &F, &Loop02PHBB);
958         NewLoop010BB =
959             BasicBlock::Create(Context, "loop.0.1.0", &F, &Loop02PHBB);
960         NewLoop01LatchBB =
961             BasicBlock::Create(Context, "loop.0.1.latch", &F, &Loop02PHBB);
962         Loop01BB.getTerminator()->replaceUsesOfWith(&Loop01BB, NewLoop010PHBB);
963         BranchInst::Create(NewLoop010BB, NewLoop010PHBB);
964         CreateCondBr(NewLoop01LatchBB, NewLoop010BB, "cond.0.1.0",
965                      NewLoop010BB);
966         BranchInst::Create(&Loop01BB, NewLoop01LatchBB);
967         AR.DT.addNewBlock(NewLoop010PHBB, &Loop01BB);
968         AR.DT.addNewBlock(NewLoop010BB, NewLoop010PHBB);
969         AR.DT.addNewBlock(NewLoop01LatchBB, NewLoop010BB);
970         EXPECT_TRUE(AR.DT.verify());
971         L.addBasicBlockToLoop(NewLoop010PHBB, AR.LI);
972         NewLoop->addBasicBlockToLoop(NewLoop010BB, AR.LI);
973         L.addBasicBlockToLoop(NewLoop01LatchBB, AR.LI);
974         NewLoop->verifyLoop();
975         L.verifyLoop();
976         Updater.addChildLoops({NewLoop});
977         return PreservedAnalyses::all();
978       }));
979 
980   // We should immediately drop down to fully visit the new inner loop.
981   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1.0"), _, _, _))
982       .WillOnce(Invoke(getLoopAnalysisResult));
983   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1.0"), _, _));
984   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1.0"), _, _, _))
985       .Times(2)
986       .WillRepeatedly(Invoke(getLoopAnalysisResult));
987 
988   // After visiting the inner loop, we should re-visit the second loop
989   // reflecting its new loop nest structure.
990   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
991       .WillOnce(Invoke(getLoopAnalysisResult));
992 
993   // In the second run over the middle loop after we've visited the new child,
994   // we add another child to check that we can repeatedly add children, and add
995   // children to a loop that already has children.
996   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
997       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
998                            LoopStandardAnalysisResults &AR,
999                            LPMUpdater &Updater) {
1000         auto *NewLoop = AR.LI.AllocateLoop();
1001         L.addChildLoop(NewLoop);
1002         auto *NewLoop011PHBB = BasicBlock::Create(Context, "loop.0.1.1.ph", &F, NewLoop01LatchBB);
1003         auto *NewLoop011BB = BasicBlock::Create(Context, "loop.0.1.1", &F, NewLoop01LatchBB);
1004         NewLoop010BB->getTerminator()->replaceUsesOfWith(NewLoop01LatchBB,
1005                                                          NewLoop011PHBB);
1006         BranchInst::Create(NewLoop011BB, NewLoop011PHBB);
1007         CreateCondBr(NewLoop01LatchBB, NewLoop011BB, "cond.0.1.1",
1008                      NewLoop011BB);
1009         AR.DT.addNewBlock(NewLoop011PHBB, NewLoop010BB);
1010         auto *NewDTNode = AR.DT.addNewBlock(NewLoop011BB, NewLoop011PHBB);
1011         AR.DT.changeImmediateDominator(AR.DT[NewLoop01LatchBB], NewDTNode);
1012         EXPECT_TRUE(AR.DT.verify());
1013         L.addBasicBlockToLoop(NewLoop011PHBB, AR.LI);
1014         NewLoop->addBasicBlockToLoop(NewLoop011BB, AR.LI);
1015         NewLoop->verifyLoop();
1016         L.verifyLoop();
1017         Updater.addChildLoops({NewLoop});
1018         return PreservedAnalyses::all();
1019       }));
1020 
1021   // Again, we should immediately drop down to visit the new, unvisited child
1022   // loop. We don't need to revisit the other child though.
1023   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1.1"), _, _, _))
1024       .WillOnce(Invoke(getLoopAnalysisResult));
1025   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1.1"), _, _));
1026   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1.1"), _, _, _))
1027       .Times(2)
1028       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1029 
1030   // And now we should pop back up to the second loop and do a full pipeline of
1031   // three passes on its current form.
1032   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1033       .Times(3)
1034       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1035 
1036   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1037       .WillOnce(Invoke(getLoopAnalysisResult));
1038   EXPECT_CALL(MLAHandle, run(HasName("loop.0.2"), _, _));
1039   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1040       .Times(2)
1041       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1042 
1043   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1044       .WillOnce(Invoke(getLoopAnalysisResult));
1045   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
1046   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1047       .Times(2)
1048       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1049 
1050   // Now that all the expected actions are registered, run the pipeline over
1051   // our module. All of our expectations are verified when the test finishes.
1052   MPM.run(*M, MAM);
1053 }
1054 
1055 TEST_F(LoopPassManagerTest, LoopPeerInsertion) {
1056   // Super boring module with two loop nests and loop nest with two child
1057   // loops.
1058   M = parseIR(Context, "define void @f(i1* %ptr) {\n"
1059                        "entry:\n"
1060                        "  br label %loop.0\n"
1061                        "loop.0:\n"
1062                        "  %cond.0 = load volatile i1, i1* %ptr\n"
1063                        "  br i1 %cond.0, label %loop.0.0.ph, label %loop.2.ph\n"
1064                        "loop.0.0.ph:\n"
1065                        "  br label %loop.0.0\n"
1066                        "loop.0.0:\n"
1067                        "  %cond.0.0 = load volatile i1, i1* %ptr\n"
1068                        "  br i1 %cond.0.0, label %loop.0.0, label %loop.0.2.ph\n"
1069                        "loop.0.2.ph:\n"
1070                        "  br label %loop.0.2\n"
1071                        "loop.0.2:\n"
1072                        "  %cond.0.2 = load volatile i1, i1* %ptr\n"
1073                        "  br i1 %cond.0.2, label %loop.0.2, label %loop.0.latch\n"
1074                        "loop.0.latch:\n"
1075                        "  br label %loop.0\n"
1076                        "loop.2.ph:\n"
1077                        "  br label %loop.2\n"
1078                        "loop.2:\n"
1079                        "  %cond.2 = load volatile i1, i1* %ptr\n"
1080                        "  br i1 %cond.2, label %loop.2, label %end\n"
1081                        "end:\n"
1082                        "  ret void\n"
1083                        "}\n");
1084 
1085   // Build up variables referring into the IR so we can rewrite it below
1086   // easily.
1087   Function &F = *M->begin();
1088   ASSERT_THAT(F, HasName("f"));
1089   Argument &Ptr = *F.arg_begin();
1090   auto BBI = F.begin();
1091   BasicBlock &EntryBB = *BBI++;
1092   ASSERT_THAT(EntryBB, HasName("entry"));
1093   BasicBlock &Loop0BB = *BBI++;
1094   ASSERT_THAT(Loop0BB, HasName("loop.0"));
1095   BasicBlock &Loop00PHBB = *BBI++;
1096   ASSERT_THAT(Loop00PHBB, HasName("loop.0.0.ph"));
1097   BasicBlock &Loop00BB = *BBI++;
1098   ASSERT_THAT(Loop00BB, HasName("loop.0.0"));
1099   BasicBlock &Loop02PHBB = *BBI++;
1100   ASSERT_THAT(Loop02PHBB, HasName("loop.0.2.ph"));
1101   BasicBlock &Loop02BB = *BBI++;
1102   ASSERT_THAT(Loop02BB, HasName("loop.0.2"));
1103   BasicBlock &Loop0LatchBB = *BBI++;
1104   ASSERT_THAT(Loop0LatchBB, HasName("loop.0.latch"));
1105   BasicBlock &Loop2PHBB = *BBI++;
1106   ASSERT_THAT(Loop2PHBB, HasName("loop.2.ph"));
1107   BasicBlock &Loop2BB = *BBI++;
1108   ASSERT_THAT(Loop2BB, HasName("loop.2"));
1109   BasicBlock &EndBB = *BBI++;
1110   ASSERT_THAT(EndBB, HasName("end"));
1111   ASSERT_THAT(BBI, F.end());
1112   auto CreateCondBr = [&](BasicBlock *TrueBB, BasicBlock *FalseBB,
1113                           const char *Name, BasicBlock *BB) {
1114     auto *Cond = new LoadInst(&Ptr, Name, /*isVolatile*/ true, BB);
1115     BranchInst::Create(TrueBB, FalseBB, Cond, BB);
1116   };
1117 
1118   // Build the pass managers and register our pipeline. We build a single loop
1119   // pass pipeline consisting of three mock pass runs over each loop. After
1120   // this we run both domtree and loop verification passes to make sure that
1121   // the IR remained valid during our mutations.
1122   ModulePassManager MPM(true);
1123   FunctionPassManager FPM(true);
1124   LoopPassManager LPM(true);
1125   LPM.addPass(MLPHandle.getPass());
1126   LPM.addPass(MLPHandle.getPass());
1127   LPM.addPass(MLPHandle.getPass());
1128   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
1129   FPM.addPass(DominatorTreeVerifierPass());
1130   FPM.addPass(LoopVerifierPass());
1131   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
1132 
1133   // All the visit orders are deterministic, so we use simple fully order
1134   // expectations.
1135   ::testing::InSequence MakeExpectationsSequenced;
1136 
1137   // We run loop passes three times over each of the loops.
1138   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1139       .WillOnce(Invoke(getLoopAnalysisResult));
1140   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
1141 
1142   // On the second run, we insert a sibling loop.
1143   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1144       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
1145                            LoopStandardAnalysisResults &AR,
1146                            LPMUpdater &Updater) {
1147         auto *NewLoop = AR.LI.AllocateLoop();
1148         L.getParentLoop()->addChildLoop(NewLoop);
1149         auto *NewLoop01PHBB = BasicBlock::Create(Context, "loop.0.1.ph", &F, &Loop02PHBB);
1150         auto *NewLoop01BB = BasicBlock::Create(Context, "loop.0.1", &F, &Loop02PHBB);
1151         BranchInst::Create(NewLoop01BB, NewLoop01PHBB);
1152         CreateCondBr(&Loop02PHBB, NewLoop01BB, "cond.0.1", NewLoop01BB);
1153         Loop00BB.getTerminator()->replaceUsesOfWith(&Loop02PHBB, NewLoop01PHBB);
1154         AR.DT.addNewBlock(NewLoop01PHBB, &Loop00BB);
1155         auto *NewDTNode = AR.DT.addNewBlock(NewLoop01BB, NewLoop01PHBB);
1156         AR.DT.changeImmediateDominator(AR.DT[&Loop02PHBB], NewDTNode);
1157         EXPECT_TRUE(AR.DT.verify());
1158         L.getParentLoop()->addBasicBlockToLoop(NewLoop01PHBB, AR.LI);
1159         NewLoop->addBasicBlockToLoop(NewLoop01BB, AR.LI);
1160         L.getParentLoop()->verifyLoop();
1161         Updater.addSiblingLoops({NewLoop});
1162         return PreservedAnalyses::all();
1163       }));
1164   // We finish processing this loop as sibling loops don't perturb the
1165   // postorder walk.
1166   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1167       .WillOnce(Invoke(getLoopAnalysisResult));
1168 
1169   // We visit the inserted sibling next.
1170   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1171       .WillOnce(Invoke(getLoopAnalysisResult));
1172   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
1173   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1174       .Times(2)
1175       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1176 
1177   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1178       .WillOnce(Invoke(getLoopAnalysisResult));
1179   EXPECT_CALL(MLAHandle, run(HasName("loop.0.2"), _, _));
1180   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1181       .WillOnce(Invoke(getLoopAnalysisResult));
1182   // Next, on the third pass run on the last inner loop we add more new
1183   // siblings, more than one, and one with nested child loops. By doing this at
1184   // the end we make sure that edge case works well.
1185   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1186       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
1187                            LoopStandardAnalysisResults &AR,
1188                            LPMUpdater &Updater) {
1189         Loop *NewLoops[] = {AR.LI.AllocateLoop(), AR.LI.AllocateLoop(),
1190                             AR.LI.AllocateLoop()};
1191         L.getParentLoop()->addChildLoop(NewLoops[0]);
1192         L.getParentLoop()->addChildLoop(NewLoops[1]);
1193         NewLoops[1]->addChildLoop(NewLoops[2]);
1194         auto *NewLoop03PHBB =
1195             BasicBlock::Create(Context, "loop.0.3.ph", &F, &Loop0LatchBB);
1196         auto *NewLoop03BB =
1197             BasicBlock::Create(Context, "loop.0.3", &F, &Loop0LatchBB);
1198         auto *NewLoop04PHBB =
1199             BasicBlock::Create(Context, "loop.0.4.ph", &F, &Loop0LatchBB);
1200         auto *NewLoop04BB =
1201             BasicBlock::Create(Context, "loop.0.4", &F, &Loop0LatchBB);
1202         auto *NewLoop040PHBB =
1203             BasicBlock::Create(Context, "loop.0.4.0.ph", &F, &Loop0LatchBB);
1204         auto *NewLoop040BB =
1205             BasicBlock::Create(Context, "loop.0.4.0", &F, &Loop0LatchBB);
1206         auto *NewLoop04LatchBB =
1207             BasicBlock::Create(Context, "loop.0.4.latch", &F, &Loop0LatchBB);
1208         Loop02BB.getTerminator()->replaceUsesOfWith(&Loop0LatchBB, NewLoop03PHBB);
1209         BranchInst::Create(NewLoop03BB, NewLoop03PHBB);
1210         CreateCondBr(NewLoop04PHBB, NewLoop03BB, "cond.0.3", NewLoop03BB);
1211         BranchInst::Create(NewLoop04BB, NewLoop04PHBB);
1212         CreateCondBr(&Loop0LatchBB, NewLoop040PHBB, "cond.0.4", NewLoop04BB);
1213         BranchInst::Create(NewLoop040BB, NewLoop040PHBB);
1214         CreateCondBr(NewLoop04LatchBB, NewLoop040BB, "cond.0.4.0", NewLoop040BB);
1215         BranchInst::Create(NewLoop04BB, NewLoop04LatchBB);
1216         AR.DT.addNewBlock(NewLoop03PHBB, &Loop02BB);
1217         AR.DT.addNewBlock(NewLoop03BB, NewLoop03PHBB);
1218         AR.DT.addNewBlock(NewLoop04PHBB, NewLoop03BB);
1219         auto *NewDTNode = AR.DT.addNewBlock(NewLoop04BB, NewLoop04PHBB);
1220         AR.DT.changeImmediateDominator(AR.DT[&Loop0LatchBB], NewDTNode);
1221         AR.DT.addNewBlock(NewLoop040PHBB, NewLoop04BB);
1222         AR.DT.addNewBlock(NewLoop040BB, NewLoop040PHBB);
1223         AR.DT.addNewBlock(NewLoop04LatchBB, NewLoop040BB);
1224         EXPECT_TRUE(AR.DT.verify());
1225         L.getParentLoop()->addBasicBlockToLoop(NewLoop03PHBB, AR.LI);
1226         NewLoops[0]->addBasicBlockToLoop(NewLoop03BB, AR.LI);
1227         L.getParentLoop()->addBasicBlockToLoop(NewLoop04PHBB, AR.LI);
1228         NewLoops[1]->addBasicBlockToLoop(NewLoop04BB, AR.LI);
1229         NewLoops[1]->addBasicBlockToLoop(NewLoop040PHBB, AR.LI);
1230         NewLoops[2]->addBasicBlockToLoop(NewLoop040BB, AR.LI);
1231         NewLoops[1]->addBasicBlockToLoop(NewLoop04LatchBB, AR.LI);
1232         L.getParentLoop()->verifyLoop();
1233         Updater.addSiblingLoops({NewLoops[0], NewLoops[1]});
1234         return PreservedAnalyses::all();
1235       }));
1236 
1237   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1238       .WillOnce(Invoke(getLoopAnalysisResult));
1239   EXPECT_CALL(MLAHandle, run(HasName("loop.0.3"), _, _));
1240   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1241       .Times(2)
1242       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1243 
1244   // Note that we need to visit the inner loop of this added sibling before the
1245   // sibling itself!
1246   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4.0"), _, _, _))
1247       .WillOnce(Invoke(getLoopAnalysisResult));
1248   EXPECT_CALL(MLAHandle, run(HasName("loop.0.4.0"), _, _));
1249   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4.0"), _, _, _))
1250       .Times(2)
1251       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1252 
1253   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4"), _, _, _))
1254       .WillOnce(Invoke(getLoopAnalysisResult));
1255   EXPECT_CALL(MLAHandle, run(HasName("loop.0.4"), _, _));
1256   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4"), _, _, _))
1257       .Times(2)
1258       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1259 
1260   // And only now do we visit the outermost loop of the nest.
1261   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1262       .WillOnce(Invoke(getLoopAnalysisResult));
1263   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
1264   // On the second pass, we add sibling loops which become new top-level loops.
1265   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1266       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
1267                            LoopStandardAnalysisResults &AR,
1268                            LPMUpdater &Updater) {
1269         auto *NewLoop = AR.LI.AllocateLoop();
1270         AR.LI.addTopLevelLoop(NewLoop);
1271         auto *NewLoop1PHBB = BasicBlock::Create(Context, "loop.1.ph", &F, &Loop2BB);
1272         auto *NewLoop1BB = BasicBlock::Create(Context, "loop.1", &F, &Loop2BB);
1273         BranchInst::Create(NewLoop1BB, NewLoop1PHBB);
1274         CreateCondBr(&Loop2PHBB, NewLoop1BB, "cond.1", NewLoop1BB);
1275         Loop0BB.getTerminator()->replaceUsesOfWith(&Loop2PHBB, NewLoop1PHBB);
1276         AR.DT.addNewBlock(NewLoop1PHBB, &Loop0BB);
1277         auto *NewDTNode = AR.DT.addNewBlock(NewLoop1BB, NewLoop1PHBB);
1278         AR.DT.changeImmediateDominator(AR.DT[&Loop2PHBB], NewDTNode);
1279         EXPECT_TRUE(AR.DT.verify());
1280         NewLoop->addBasicBlockToLoop(NewLoop1BB, AR.LI);
1281         NewLoop->verifyLoop();
1282         Updater.addSiblingLoops({NewLoop});
1283         return PreservedAnalyses::all();
1284       }));
1285   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1286       .WillOnce(Invoke(getLoopAnalysisResult));
1287 
1288   EXPECT_CALL(MLPHandle, run(HasName("loop.1"), _, _, _))
1289       .WillOnce(Invoke(getLoopAnalysisResult));
1290   EXPECT_CALL(MLAHandle, run(HasName("loop.1"), _, _));
1291   EXPECT_CALL(MLPHandle, run(HasName("loop.1"), _, _, _))
1292       .Times(2)
1293       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1294 
1295   EXPECT_CALL(MLPHandle, run(HasName("loop.2"), _, _, _))
1296       .WillOnce(Invoke(getLoopAnalysisResult));
1297   EXPECT_CALL(MLAHandle, run(HasName("loop.2"), _, _));
1298   EXPECT_CALL(MLPHandle, run(HasName("loop.2"), _, _, _))
1299       .Times(2)
1300       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1301 
1302   // Now that all the expected actions are registered, run the pipeline over
1303   // our module. All of our expectations are verified when the test finishes.
1304   MPM.run(*M, MAM);
1305 }
1306 
1307 TEST_F(LoopPassManagerTest, LoopDeletion) {
1308   // Build a module with a single loop nest that contains one outer loop with
1309   // three subloops, and one of those with its own subloop. We will
1310   // incrementally delete all of these to test different deletion scenarios.
1311   M = parseIR(Context, "define void @f(i1* %ptr) {\n"
1312                        "entry:\n"
1313                        "  br label %loop.0\n"
1314                        "loop.0:\n"
1315                        "  %cond.0 = load volatile i1, i1* %ptr\n"
1316                        "  br i1 %cond.0, label %loop.0.0.ph, label %end\n"
1317                        "loop.0.0.ph:\n"
1318                        "  br label %loop.0.0\n"
1319                        "loop.0.0:\n"
1320                        "  %cond.0.0 = load volatile i1, i1* %ptr\n"
1321                        "  br i1 %cond.0.0, label %loop.0.0, label %loop.0.1.ph\n"
1322                        "loop.0.1.ph:\n"
1323                        "  br label %loop.0.1\n"
1324                        "loop.0.1:\n"
1325                        "  %cond.0.1 = load volatile i1, i1* %ptr\n"
1326                        "  br i1 %cond.0.1, label %loop.0.1, label %loop.0.2.ph\n"
1327                        "loop.0.2.ph:\n"
1328                        "  br label %loop.0.2\n"
1329                        "loop.0.2:\n"
1330                        "  %cond.0.2 = load volatile i1, i1* %ptr\n"
1331                        "  br i1 %cond.0.2, label %loop.0.2.0.ph, label %loop.0.latch\n"
1332                        "loop.0.2.0.ph:\n"
1333                        "  br label %loop.0.2.0\n"
1334                        "loop.0.2.0:\n"
1335                        "  %cond.0.2.0 = load volatile i1, i1* %ptr\n"
1336                        "  br i1 %cond.0.2.0, label %loop.0.2.0, label %loop.0.2.latch\n"
1337                        "loop.0.2.latch:\n"
1338                        "  br label %loop.0.2\n"
1339                        "loop.0.latch:\n"
1340                        "  br label %loop.0\n"
1341                        "end:\n"
1342                        "  ret void\n"
1343                        "}\n");
1344 
1345   // Build up variables referring into the IR so we can rewrite it below
1346   // easily.
1347   Function &F = *M->begin();
1348   ASSERT_THAT(F, HasName("f"));
1349   Argument &Ptr = *F.arg_begin();
1350   auto BBI = F.begin();
1351   BasicBlock &EntryBB = *BBI++;
1352   ASSERT_THAT(EntryBB, HasName("entry"));
1353   BasicBlock &Loop0BB = *BBI++;
1354   ASSERT_THAT(Loop0BB, HasName("loop.0"));
1355   BasicBlock &Loop00PHBB = *BBI++;
1356   ASSERT_THAT(Loop00PHBB, HasName("loop.0.0.ph"));
1357   BasicBlock &Loop00BB = *BBI++;
1358   ASSERT_THAT(Loop00BB, HasName("loop.0.0"));
1359   BasicBlock &Loop01PHBB = *BBI++;
1360   ASSERT_THAT(Loop01PHBB, HasName("loop.0.1.ph"));
1361   BasicBlock &Loop01BB = *BBI++;
1362   ASSERT_THAT(Loop01BB, HasName("loop.0.1"));
1363   BasicBlock &Loop02PHBB = *BBI++;
1364   ASSERT_THAT(Loop02PHBB, HasName("loop.0.2.ph"));
1365   BasicBlock &Loop02BB = *BBI++;
1366   ASSERT_THAT(Loop02BB, HasName("loop.0.2"));
1367   BasicBlock &Loop020PHBB = *BBI++;
1368   ASSERT_THAT(Loop020PHBB, HasName("loop.0.2.0.ph"));
1369   BasicBlock &Loop020BB = *BBI++;
1370   ASSERT_THAT(Loop020BB, HasName("loop.0.2.0"));
1371   BasicBlock &Loop02LatchBB = *BBI++;
1372   ASSERT_THAT(Loop02LatchBB, HasName("loop.0.2.latch"));
1373   BasicBlock &Loop0LatchBB = *BBI++;
1374   ASSERT_THAT(Loop0LatchBB, HasName("loop.0.latch"));
1375   BasicBlock &EndBB = *BBI++;
1376   ASSERT_THAT(EndBB, HasName("end"));
1377   ASSERT_THAT(BBI, F.end());
1378 
1379   // Helper to do the actual deletion of a loop. We directly encode this here
1380   // to isolate ourselves from the rest of LLVM and for simplicity. Here we can
1381   // egregiously cheat based on knowledge of the test case. For example, we
1382   // have no PHI nodes and there is always a single i-dom.
1383   auto EraseLoop = [](Loop &L, BasicBlock &IDomBB,
1384                       LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1385     assert(L.empty() && "Can only delete leaf loops with this routine!");
1386     SmallVector<BasicBlock *, 4> LoopBBs(L.block_begin(), L.block_end());
1387     Updater.markLoopAsDeleted(L, L.getName());
1388     IDomBB.getTerminator()->replaceUsesOfWith(L.getHeader(),
1389                                               L.getUniqueExitBlock());
1390     for (BasicBlock *LoopBB : LoopBBs) {
1391       SmallVector<DomTreeNode *, 4> ChildNodes(AR.DT[LoopBB]->begin(),
1392                                                AR.DT[LoopBB]->end());
1393       for (DomTreeNode *ChildNode : ChildNodes)
1394         AR.DT.changeImmediateDominator(ChildNode, AR.DT[&IDomBB]);
1395       AR.DT.eraseNode(LoopBB);
1396       AR.LI.removeBlock(LoopBB);
1397       LoopBB->dropAllReferences();
1398     }
1399     for (BasicBlock *LoopBB : LoopBBs)
1400       LoopBB->eraseFromParent();
1401 
1402     AR.LI.erase(&L);
1403   };
1404 
1405   // Build up the pass managers.
1406   ModulePassManager MPM(true);
1407   FunctionPassManager FPM(true);
1408   // We run several loop pass pipelines across the loop nest, but they all take
1409   // the same form of three mock pass runs in a loop pipeline followed by
1410   // domtree and loop verification. We use a lambda to stamp this out each
1411   // time.
1412   auto AddLoopPipelineAndVerificationPasses = [&] {
1413     LoopPassManager LPM(true);
1414     LPM.addPass(MLPHandle.getPass());
1415     LPM.addPass(MLPHandle.getPass());
1416     LPM.addPass(MLPHandle.getPass());
1417     FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
1418     FPM.addPass(DominatorTreeVerifierPass());
1419     FPM.addPass(LoopVerifierPass());
1420   };
1421 
1422   // All the visit orders are deterministic so we use simple fully order
1423   // expectations.
1424   ::testing::InSequence MakeExpectationsSequenced;
1425 
1426   // We run the loop pipeline with three passes over each of the loops. When
1427   // running over the middle loop, the second pass in the pipeline deletes it.
1428   // This should prevent the third pass from visiting it but otherwise leave
1429   // the process unimpacted.
1430   AddLoopPipelineAndVerificationPasses();
1431   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1432       .WillOnce(Invoke(getLoopAnalysisResult));
1433   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
1434   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1435       .Times(2)
1436       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1437 
1438   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1439       .WillOnce(Invoke(getLoopAnalysisResult));
1440   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
1441   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1442       .WillOnce(
1443           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1444                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1445             Loop *ParentL = L.getParentLoop();
1446             AR.SE.forgetLoop(&L);
1447             EraseLoop(L, Loop01PHBB, AR, Updater);
1448             ParentL->verifyLoop();
1449             return PreservedAnalyses::all();
1450           }));
1451 
1452   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2.0"), _, _, _))
1453       .WillOnce(Invoke(getLoopAnalysisResult));
1454   EXPECT_CALL(MLAHandle, run(HasName("loop.0.2.0"), _, _));
1455   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2.0"), _, _, _))
1456       .Times(2)
1457       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1458 
1459   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1460       .WillOnce(Invoke(getLoopAnalysisResult));
1461   EXPECT_CALL(MLAHandle, run(HasName("loop.0.2"), _, _));
1462   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1463       .Times(2)
1464       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1465 
1466   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1467       .WillOnce(Invoke(getLoopAnalysisResult));
1468   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
1469   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1470       .Times(2)
1471       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1472 
1473   // Run the loop pipeline again. This time we delete the last loop, which
1474   // contains a nested loop within it and insert a new loop into the nest. This
1475   // makes sure we can handle nested loop deletion.
1476   AddLoopPipelineAndVerificationPasses();
1477   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1478       .Times(3)
1479       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1480 
1481   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2.0"), _, _, _))
1482       .Times(3)
1483       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1484 
1485   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1486       .WillOnce(Invoke(getLoopAnalysisResult));
1487   BasicBlock *NewLoop03PHBB;
1488   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1489       .WillOnce(
1490           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1491                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1492             AR.SE.forgetLoop(*L.begin());
1493             EraseLoop(**L.begin(), Loop020PHBB, AR, Updater);
1494 
1495             auto *ParentL = L.getParentLoop();
1496             AR.SE.forgetLoop(&L);
1497             EraseLoop(L, Loop02PHBB, AR, Updater);
1498 
1499             // Now insert a new sibling loop.
1500             auto *NewSibling = AR.LI.AllocateLoop();
1501             ParentL->addChildLoop(NewSibling);
1502             NewLoop03PHBB =
1503                 BasicBlock::Create(Context, "loop.0.3.ph", &F, &Loop0LatchBB);
1504             auto *NewLoop03BB =
1505                 BasicBlock::Create(Context, "loop.0.3", &F, &Loop0LatchBB);
1506             BranchInst::Create(NewLoop03BB, NewLoop03PHBB);
1507             auto *Cond = new LoadInst(&Ptr, "cond.0.3", /*isVolatile*/ true,
1508                                       NewLoop03BB);
1509             BranchInst::Create(&Loop0LatchBB, NewLoop03BB, Cond, NewLoop03BB);
1510             Loop02PHBB.getTerminator()->replaceUsesOfWith(&Loop0LatchBB,
1511                                                           NewLoop03PHBB);
1512             AR.DT.addNewBlock(NewLoop03PHBB, &Loop02PHBB);
1513             AR.DT.addNewBlock(NewLoop03BB, NewLoop03PHBB);
1514             AR.DT.changeImmediateDominator(AR.DT[&Loop0LatchBB],
1515                                            AR.DT[NewLoop03BB]);
1516             EXPECT_TRUE(AR.DT.verify());
1517             ParentL->addBasicBlockToLoop(NewLoop03PHBB, AR.LI);
1518             NewSibling->addBasicBlockToLoop(NewLoop03BB, AR.LI);
1519             NewSibling->verifyLoop();
1520             ParentL->verifyLoop();
1521             Updater.addSiblingLoops({NewSibling});
1522             return PreservedAnalyses::all();
1523           }));
1524 
1525   // To respect our inner-to-outer traversal order, we must visit the
1526   // newly-inserted sibling of the loop we just deleted before we visit the
1527   // outer loop. When we do so, this must compute a fresh analysis result, even
1528   // though our new loop has the same pointer value as the loop we deleted.
1529   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1530       .WillOnce(Invoke(getLoopAnalysisResult));
1531   EXPECT_CALL(MLAHandle, run(HasName("loop.0.3"), _, _));
1532   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1533       .Times(2)
1534       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1535 
1536   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1537       .Times(3)
1538       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1539 
1540   // In the final loop pipeline run we delete every loop, including the last
1541   // loop of the nest. We do this again in the second pass in the pipeline, and
1542   // as a consequence we never make it to three runs on any loop. We also cover
1543   // deleting multiple loops in a single pipeline, deleting the first loop and
1544   // deleting the (last) top level loop.
1545   AddLoopPipelineAndVerificationPasses();
1546   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1547       .WillOnce(Invoke(getLoopAnalysisResult));
1548   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1549       .WillOnce(
1550           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1551                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1552             AR.SE.forgetLoop(&L);
1553             EraseLoop(L, Loop00PHBB, AR, Updater);
1554             return PreservedAnalyses::all();
1555           }));
1556 
1557   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1558       .WillOnce(Invoke(getLoopAnalysisResult));
1559   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1560       .WillOnce(
1561           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1562                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1563             AR.SE.forgetLoop(&L);
1564             EraseLoop(L, *NewLoop03PHBB, AR, Updater);
1565             return PreservedAnalyses::all();
1566           }));
1567 
1568   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1569       .WillOnce(Invoke(getLoopAnalysisResult));
1570   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1571       .WillOnce(
1572           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1573                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1574             AR.SE.forgetLoop(&L);
1575             EraseLoop(L, EntryBB, AR, Updater);
1576             return PreservedAnalyses::all();
1577           }));
1578 
1579   // Add the function pass pipeline now that it is fully built up and run it
1580   // over the module's one function.
1581   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
1582   MPM.run(*M, MAM);
1583 }
1584 }
1585