1 //===- llvm/unittest/Analysis/LoopPassManagerTest.cpp - LPM tests ---------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/Transforms/Scalar/LoopPassManager.h"
10 #include "llvm/Analysis/AliasAnalysis.h"
11 #include "llvm/Analysis/AssumptionCache.h"
12 #include "llvm/Analysis/ScalarEvolution.h"
13 #include "llvm/Analysis/TargetLibraryInfo.h"
14 #include "llvm/Analysis/TargetTransformInfo.h"
15 #include "llvm/AsmParser/Parser.h"
16 #include "llvm/IR/Dominators.h"
17 #include "llvm/IR/Function.h"
18 #include "llvm/IR/LLVMContext.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/IR/PassManager.h"
21 #include "llvm/Support/SourceMgr.h"
22 
23 #include "gmock/gmock.h"
24 #include "gtest/gtest.h"
25 
26 using namespace llvm;
27 
28 namespace {
29 
30 using testing::DoDefault;
31 using testing::Return;
32 using testing::Expectation;
33 using testing::Invoke;
34 using testing::InvokeWithoutArgs;
35 using testing::_;
36 
37 template <typename DerivedT, typename IRUnitT,
38           typename AnalysisManagerT = AnalysisManager<IRUnitT>,
39           typename... ExtraArgTs>
40 class MockAnalysisHandleBase {
41 public:
42   class Analysis : public AnalysisInfoMixin<Analysis> {
43     friend AnalysisInfoMixin<Analysis>;
44     friend MockAnalysisHandleBase;
45     static AnalysisKey Key;
46 
47     DerivedT *Handle;
48 
49     Analysis(DerivedT &Handle) : Handle(&Handle) {
50       static_assert(std::is_base_of<MockAnalysisHandleBase, DerivedT>::value,
51                     "Must pass the derived type to this template!");
52     }
53 
54   public:
55     class Result {
56       friend MockAnalysisHandleBase;
57 
58       DerivedT *Handle;
59 
60       Result(DerivedT &Handle) : Handle(&Handle) {}
61 
62     public:
63       // Forward invalidation events to the mock handle.
64       bool invalidate(IRUnitT &IR, const PreservedAnalyses &PA,
65                       typename AnalysisManagerT::Invalidator &Inv) {
66         return Handle->invalidate(IR, PA, Inv);
67       }
68     };
69 
70     Result run(IRUnitT &IR, AnalysisManagerT &AM, ExtraArgTs... ExtraArgs) {
71       return Handle->run(IR, AM, ExtraArgs...);
72     }
73   };
74 
75   Analysis getAnalysis() { return Analysis(static_cast<DerivedT &>(*this)); }
76   typename Analysis::Result getResult() {
77     return typename Analysis::Result(static_cast<DerivedT &>(*this));
78   }
79 
80 protected:
81   // FIXME: MSVC seems unable to handle a lambda argument to Invoke from within
82   // the template, so we use a boring static function.
83   static bool invalidateCallback(IRUnitT &IR, const PreservedAnalyses &PA,
84                                  typename AnalysisManagerT::Invalidator &Inv) {
85     auto PAC = PA.template getChecker<Analysis>();
86     return !PAC.preserved() &&
87            !PAC.template preservedSet<AllAnalysesOn<IRUnitT>>();
88   }
89 
90   /// Derived classes should call this in their constructor to set up default
91   /// mock actions. (We can't do this in our constructor because this has to
92   /// run after the DerivedT is constructed.)
93   void setDefaults() {
94     ON_CALL(static_cast<DerivedT &>(*this),
95             run(_, _, testing::Matcher<ExtraArgTs>(_)...))
96         .WillByDefault(Return(this->getResult()));
97     ON_CALL(static_cast<DerivedT &>(*this), invalidate(_, _, _))
98         .WillByDefault(Invoke(&invalidateCallback));
99   }
100 };
101 
102 template <typename DerivedT, typename IRUnitT, typename AnalysisManagerT,
103           typename... ExtraArgTs>
104 AnalysisKey MockAnalysisHandleBase<DerivedT, IRUnitT, AnalysisManagerT,
105                                    ExtraArgTs...>::Analysis::Key;
106 
107 /// Mock handle for loop analyses.
108 ///
109 /// This is provided as a template accepting an (optional) integer. Because
110 /// analyses are identified and queried by type, this allows constructing
111 /// multiple handles with distinctly typed nested 'Analysis' types that can be
112 /// registered and queried. If you want to register multiple loop analysis
113 /// passes, you'll need to instantiate this type with different values for I.
114 /// For example:
115 ///
116 ///   MockLoopAnalysisHandleTemplate<0> h0;
117 ///   MockLoopAnalysisHandleTemplate<1> h1;
118 ///   typedef decltype(h0)::Analysis Analysis0;
119 ///   typedef decltype(h1)::Analysis Analysis1;
120 template <size_t I = static_cast<size_t>(-1)>
121 struct MockLoopAnalysisHandleTemplate
122     : MockAnalysisHandleBase<MockLoopAnalysisHandleTemplate<I>, Loop,
123                              LoopAnalysisManager,
124                              LoopStandardAnalysisResults &> {
125   typedef typename MockLoopAnalysisHandleTemplate::Analysis Analysis;
126 
127   MOCK_METHOD3_T(run, typename Analysis::Result(Loop &, LoopAnalysisManager &,
128                                                 LoopStandardAnalysisResults &));
129 
130   MOCK_METHOD3_T(invalidate, bool(Loop &, const PreservedAnalyses &,
131                                   LoopAnalysisManager::Invalidator &));
132 
133   MockLoopAnalysisHandleTemplate() { this->setDefaults(); }
134 };
135 
136 typedef MockLoopAnalysisHandleTemplate<> MockLoopAnalysisHandle;
137 
138 struct MockFunctionAnalysisHandle
139     : MockAnalysisHandleBase<MockFunctionAnalysisHandle, Function> {
140   MOCK_METHOD2(run, Analysis::Result(Function &, FunctionAnalysisManager &));
141 
142   MOCK_METHOD3(invalidate, bool(Function &, const PreservedAnalyses &,
143                                 FunctionAnalysisManager::Invalidator &));
144 
145   MockFunctionAnalysisHandle() { setDefaults(); }
146 };
147 
148 template <typename DerivedT, typename IRUnitT,
149           typename AnalysisManagerT = AnalysisManager<IRUnitT>,
150           typename... ExtraArgTs>
151 class MockPassHandleBase {
152 public:
153   class Pass : public PassInfoMixin<Pass> {
154     friend MockPassHandleBase;
155 
156     DerivedT *Handle;
157 
158     Pass(DerivedT &Handle) : Handle(&Handle) {
159       static_assert(std::is_base_of<MockPassHandleBase, DerivedT>::value,
160                     "Must pass the derived type to this template!");
161     }
162 
163   public:
164     PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM,
165                           ExtraArgTs... ExtraArgs) {
166       return Handle->run(IR, AM, ExtraArgs...);
167     }
168   };
169 
170   Pass getPass() { return Pass(static_cast<DerivedT &>(*this)); }
171 
172 protected:
173   /// Derived classes should call this in their constructor to set up default
174   /// mock actions. (We can't do this in our constructor because this has to
175   /// run after the DerivedT is constructed.)
176   void setDefaults() {
177     ON_CALL(static_cast<DerivedT &>(*this),
178             run(_, _, testing::Matcher<ExtraArgTs>(_)...))
179         .WillByDefault(Return(PreservedAnalyses::all()));
180   }
181 };
182 
183 struct MockLoopPassHandle
184     : MockPassHandleBase<MockLoopPassHandle, Loop, LoopAnalysisManager,
185                          LoopStandardAnalysisResults &, LPMUpdater &> {
186   MOCK_METHOD4(run,
187                PreservedAnalyses(Loop &, LoopAnalysisManager &,
188                                  LoopStandardAnalysisResults &, LPMUpdater &));
189   MockLoopPassHandle() { setDefaults(); }
190 };
191 
192 struct MockFunctionPassHandle
193     : MockPassHandleBase<MockFunctionPassHandle, Function> {
194   MOCK_METHOD2(run, PreservedAnalyses(Function &, FunctionAnalysisManager &));
195 
196   MockFunctionPassHandle() { setDefaults(); }
197 };
198 
199 struct MockModulePassHandle : MockPassHandleBase<MockModulePassHandle, Module> {
200   MOCK_METHOD2(run, PreservedAnalyses(Module &, ModuleAnalysisManager &));
201 
202   MockModulePassHandle() { setDefaults(); }
203 };
204 
205 /// Define a custom matcher for objects which support a 'getName' method
206 /// returning a StringRef.
207 ///
208 /// LLVM often has IR objects or analysis objects which expose a StringRef name
209 /// and in tests it is convenient to match these by name for readability. This
210 /// matcher supports any type exposing a getName() method of this form.
211 ///
212 /// It should be used as:
213 ///
214 ///   HasName("my_function")
215 ///
216 /// No namespace or other qualification is required.
217 MATCHER_P(HasName, Name, "") {
218   // The matcher's name and argument are printed in the case of failure, but we
219   // also want to print out the name of the argument. This uses an implicitly
220   // avaiable std::ostream, so we have to construct a std::string.
221   *result_listener << "has name '" << arg.getName().str() << "'";
222   return Name == arg.getName();
223 }
224 
225 std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
226   SMDiagnostic Err;
227   return parseAssemblyString(IR, Err, C);
228 }
229 
230 class LoopPassManagerTest : public ::testing::Test {
231 protected:
232   LLVMContext Context;
233   std::unique_ptr<Module> M;
234 
235   LoopAnalysisManager LAM;
236   FunctionAnalysisManager FAM;
237   ModuleAnalysisManager MAM;
238 
239   MockLoopAnalysisHandle MLAHandle;
240   MockLoopPassHandle MLPHandle;
241   MockFunctionPassHandle MFPHandle;
242   MockModulePassHandle MMPHandle;
243 
244   static PreservedAnalyses
245   getLoopAnalysisResult(Loop &L, LoopAnalysisManager &AM,
246                         LoopStandardAnalysisResults &AR, LPMUpdater &) {
247     (void)AM.getResult<MockLoopAnalysisHandle::Analysis>(L, AR);
248     return PreservedAnalyses::all();
249   };
250 
251 public:
252   LoopPassManagerTest()
253       : M(parseIR(Context,
254                   "define void @f(i1* %ptr) {\n"
255                   "entry:\n"
256                   "  br label %loop.0\n"
257                   "loop.0:\n"
258                   "  %cond.0 = load volatile i1, i1* %ptr\n"
259                   "  br i1 %cond.0, label %loop.0.0.ph, label %end\n"
260                   "loop.0.0.ph:\n"
261                   "  br label %loop.0.0\n"
262                   "loop.0.0:\n"
263                   "  %cond.0.0 = load volatile i1, i1* %ptr\n"
264                   "  br i1 %cond.0.0, label %loop.0.0, label %loop.0.1.ph\n"
265                   "loop.0.1.ph:\n"
266                   "  br label %loop.0.1\n"
267                   "loop.0.1:\n"
268                   "  %cond.0.1 = load volatile i1, i1* %ptr\n"
269                   "  br i1 %cond.0.1, label %loop.0.1, label %loop.0.latch\n"
270                   "loop.0.latch:\n"
271                   "  br label %loop.0\n"
272                   "end:\n"
273                   "  ret void\n"
274                   "}\n"
275                   "\n"
276                   "define void @g(i1* %ptr) {\n"
277                   "entry:\n"
278                   "  br label %loop.g.0\n"
279                   "loop.g.0:\n"
280                   "  %cond.0 = load volatile i1, i1* %ptr\n"
281                   "  br i1 %cond.0, label %loop.g.0, label %end\n"
282                   "end:\n"
283                   "  ret void\n"
284                   "}\n")),
285         LAM(true), FAM(true), MAM(true) {
286     // Register our mock analysis.
287     LAM.registerPass([&] { return MLAHandle.getAnalysis(); });
288 
289     // We need DominatorTreeAnalysis for LoopAnalysis.
290     FAM.registerPass([&] { return DominatorTreeAnalysis(); });
291     FAM.registerPass([&] { return LoopAnalysis(); });
292     // We also allow loop passes to assume a set of other analyses and so need
293     // those.
294     FAM.registerPass([&] { return AAManager(); });
295     FAM.registerPass([&] { return AssumptionAnalysis(); });
296     FAM.registerPass([&] { return MemorySSAAnalysis(); });
297     FAM.registerPass([&] { return ScalarEvolutionAnalysis(); });
298     FAM.registerPass([&] { return TargetLibraryAnalysis(); });
299     FAM.registerPass([&] { return TargetIRAnalysis(); });
300 
301     // Register required pass instrumentation analysis.
302     LAM.registerPass([&] { return PassInstrumentationAnalysis(); });
303     FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
304     MAM.registerPass([&] { return PassInstrumentationAnalysis(); });
305 
306     // Cross-register proxies.
307     LAM.registerPass([&] { return FunctionAnalysisManagerLoopProxy(FAM); });
308     FAM.registerPass([&] { return LoopAnalysisManagerFunctionProxy(LAM); });
309     FAM.registerPass([&] { return ModuleAnalysisManagerFunctionProxy(MAM); });
310     MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(FAM); });
311   }
312 };
313 
314 TEST_F(LoopPassManagerTest, Basic) {
315   ModulePassManager MPM(true);
316   ::testing::InSequence MakeExpectationsSequenced;
317 
318   // First we just visit all the loops in all the functions and get their
319   // analysis results. This will run the analysis a total of four times,
320   // once for each loop.
321   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
322       .WillOnce(Invoke(getLoopAnalysisResult));
323   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
324   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
325       .WillOnce(Invoke(getLoopAnalysisResult));
326   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
327   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
328       .WillOnce(Invoke(getLoopAnalysisResult));
329   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
330   EXPECT_CALL(MLPHandle, run(HasName("loop.g.0"), _, _, _))
331       .WillOnce(Invoke(getLoopAnalysisResult));
332   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
333   // Wire the loop pass through pass managers into the module pipeline.
334   {
335     LoopPassManager LPM(true);
336     LPM.addPass(MLPHandle.getPass());
337     FunctionPassManager FPM(true);
338     FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
339     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
340   }
341 
342   // Next we run two passes over the loops. The first one invalidates the
343   // analyses for one loop, the second ones try to get the analysis results.
344   // This should force only one analysis to re-run within the loop PM, but will
345   // also invalidate everything after the loop pass manager finishes.
346   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
347       .WillOnce(DoDefault())
348       .WillOnce(Invoke(getLoopAnalysisResult));
349   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
350       .WillOnce(InvokeWithoutArgs([] { return PreservedAnalyses::none(); }))
351       .WillOnce(Invoke(getLoopAnalysisResult));
352   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
353   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
354       .WillOnce(DoDefault())
355       .WillOnce(Invoke(getLoopAnalysisResult));
356   EXPECT_CALL(MLPHandle, run(HasName("loop.g.0"), _, _, _))
357       .WillOnce(DoDefault())
358       .WillOnce(Invoke(getLoopAnalysisResult));
359   // Wire two loop pass runs into the module pipeline.
360   {
361     LoopPassManager LPM(true);
362     LPM.addPass(MLPHandle.getPass());
363     LPM.addPass(MLPHandle.getPass());
364     FunctionPassManager FPM(true);
365     FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
366     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
367   }
368 
369   // And now run the pipeline across the module.
370   MPM.run(*M, MAM);
371 }
372 
373 TEST_F(LoopPassManagerTest, FunctionPassInvalidationOfLoopAnalyses) {
374   ModulePassManager MPM(true);
375   FunctionPassManager FPM(true);
376   // We process each function completely in sequence.
377   ::testing::Sequence FSequence, GSequence;
378 
379   // First, force the analysis result to be computed for each loop.
380   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _))
381       .InSequence(FSequence)
382       .WillOnce(DoDefault());
383   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _))
384       .InSequence(FSequence)
385       .WillOnce(DoDefault());
386   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _))
387       .InSequence(FSequence)
388       .WillOnce(DoDefault());
389   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _))
390       .InSequence(GSequence)
391       .WillOnce(DoDefault());
392   FPM.addPass(createFunctionToLoopPassAdaptor(
393       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
394 
395   // No need to re-run if we require again from a fresh loop pass manager.
396   FPM.addPass(createFunctionToLoopPassAdaptor(
397       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
398   // For 'f', preserve most things but not the specific loop analyses.
399   auto PA = getLoopPassPreservedAnalyses();
400   if (EnableMSSALoopDependency)
401     PA.preserve<MemorySSAAnalysis>();
402   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
403       .InSequence(FSequence)
404       .WillOnce(Return(PA));
405   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.0"), _, _))
406       .InSequence(FSequence)
407       .WillOnce(DoDefault());
408   // On one loop, skip the invalidation (as though we did an internal update).
409   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.1"), _, _))
410       .InSequence(FSequence)
411       .WillOnce(Return(false));
412   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0"), _, _))
413       .InSequence(FSequence)
414       .WillOnce(DoDefault());
415   // Now two loops still have to be recomputed.
416   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _))
417       .InSequence(FSequence)
418       .WillOnce(DoDefault());
419   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _))
420       .InSequence(FSequence)
421       .WillOnce(DoDefault());
422   // Preserve things in the second function to ensure invalidation remains
423   // isolated to one function.
424   EXPECT_CALL(MFPHandle, run(HasName("g"), _))
425       .InSequence(GSequence)
426       .WillOnce(DoDefault());
427   FPM.addPass(MFPHandle.getPass());
428   FPM.addPass(createFunctionToLoopPassAdaptor(
429       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
430 
431   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
432       .InSequence(FSequence)
433       .WillOnce(DoDefault());
434   // For 'g', fail to preserve anything, causing the loops themselves to be
435   // cleared. We don't get an invalidation event here as the loop is gone, but
436   // we should still have to recompute the analysis.
437   EXPECT_CALL(MFPHandle, run(HasName("g"), _))
438       .InSequence(GSequence)
439       .WillOnce(Return(PreservedAnalyses::none()));
440   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _))
441       .InSequence(GSequence)
442       .WillOnce(DoDefault());
443   FPM.addPass(MFPHandle.getPass());
444   FPM.addPass(createFunctionToLoopPassAdaptor(
445       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
446 
447   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
448 
449   // Verify with a separate function pass run that we didn't mess up 'f's
450   // cache. No analysis runs should be necessary here.
451   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
452       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
453 
454   MPM.run(*M, MAM);
455 }
456 
457 TEST_F(LoopPassManagerTest, ModulePassInvalidationOfLoopAnalyses) {
458   ModulePassManager MPM(true);
459   ::testing::InSequence MakeExpectationsSequenced;
460 
461   // First, force the analysis result to be computed for each loop.
462   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
463   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
464   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
465   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
466   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
467       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
468 
469   // Walking all the way out and all the way back in doesn't re-run the
470   // analysis.
471   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
472       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
473 
474   // But a module pass that doesn't preserve the actual mock loop analysis
475   // invalidates all the way down and forces recomputing.
476   EXPECT_CALL(MMPHandle, run(_, _)).WillOnce(InvokeWithoutArgs([] {
477     auto PA = getLoopPassPreservedAnalyses();
478     PA.preserve<FunctionAnalysisManagerModuleProxy>();
479     if (EnableMSSALoopDependency)
480       PA.preserve<MemorySSAAnalysis>();
481     return PA;
482   }));
483   // All the loop analyses from both functions get invalidated before we
484   // recompute anything.
485   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.0"), _, _));
486   // On one loop, again skip the invalidation (as though we did an internal
487   // update).
488   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.1"), _, _))
489       .WillOnce(Return(false));
490   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0"), _, _));
491   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.g.0"), _, _));
492   // Now all but one of the loops gets re-analyzed.
493   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
494   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
495   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
496   MPM.addPass(MMPHandle.getPass());
497   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
498       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
499 
500   // Verify that the cached values persist.
501   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
502       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
503 
504   // Now we fail to preserve the loop analysis and observe that the loop
505   // analyses are cleared (so no invalidation event) as the loops themselves
506   // are no longer valid.
507   EXPECT_CALL(MMPHandle, run(_, _)).WillOnce(InvokeWithoutArgs([] {
508     auto PA = PreservedAnalyses::none();
509     PA.preserve<FunctionAnalysisManagerModuleProxy>();
510     return PA;
511   }));
512   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
513   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
514   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
515   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
516   MPM.addPass(MMPHandle.getPass());
517   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
518       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
519 
520   // Verify that the cached values persist.
521   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
522       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
523 
524   // Next, check that even if we preserve everything within the function itelf,
525   // if the function's module pass proxy isn't preserved and the potential set
526   // of functions changes, the clear reaches the loop analyses as well. This
527   // will again trigger re-runs but not invalidation events.
528   EXPECT_CALL(MMPHandle, run(_, _)).WillOnce(InvokeWithoutArgs([] {
529     auto PA = PreservedAnalyses::none();
530     PA.preserveSet<AllAnalysesOn<Function>>();
531     PA.preserveSet<AllAnalysesOn<Loop>>();
532     return PA;
533   }));
534   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
535   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
536   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
537   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
538   MPM.addPass(MMPHandle.getPass());
539   MPM.addPass(createModuleToFunctionPassAdaptor(createFunctionToLoopPassAdaptor(
540       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>())));
541 
542   MPM.run(*M, MAM);
543 }
544 
545 // Test that if any of the bundled analyses provided in the LPM's signature
546 // become invalid, the analysis proxy itself becomes invalid and we clear all
547 // loop analysis results.
548 TEST_F(LoopPassManagerTest, InvalidationOfBundledAnalyses) {
549   ModulePassManager MPM(true);
550   FunctionPassManager FPM(true);
551   ::testing::InSequence MakeExpectationsSequenced;
552 
553   // First, force the analysis result to be computed for each loop.
554   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
555   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
556   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
557   FPM.addPass(createFunctionToLoopPassAdaptor(
558       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
559 
560   // No need to re-run if we require again from a fresh loop pass manager.
561   FPM.addPass(createFunctionToLoopPassAdaptor(
562       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
563 
564   // Preserving everything but the loop analyses themselves results in
565   // invalidation and running.
566   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
567       .WillOnce(Return(getLoopPassPreservedAnalyses()));
568   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
569   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
570   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
571   FPM.addPass(MFPHandle.getPass());
572   FPM.addPass(createFunctionToLoopPassAdaptor(
573       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
574 
575   // The rest don't invalidate analyses, they only trigger re-runs because we
576   // clear the cache completely.
577   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
578     auto PA = PreservedAnalyses::none();
579     // Not preserving `AAManager`.
580     PA.preserve<DominatorTreeAnalysis>();
581     PA.preserve<LoopAnalysis>();
582     PA.preserve<LoopAnalysisManagerFunctionProxy>();
583     PA.preserve<ScalarEvolutionAnalysis>();
584     return PA;
585   }));
586   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
587   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
588   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
589   FPM.addPass(MFPHandle.getPass());
590   FPM.addPass(createFunctionToLoopPassAdaptor(
591       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
592 
593   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
594     auto PA = PreservedAnalyses::none();
595     PA.preserve<AAManager>();
596     // Not preserving `DominatorTreeAnalysis`.
597     PA.preserve<LoopAnalysis>();
598     PA.preserve<LoopAnalysisManagerFunctionProxy>();
599     PA.preserve<ScalarEvolutionAnalysis>();
600     return PA;
601   }));
602   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
603   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
604   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
605   FPM.addPass(MFPHandle.getPass());
606   FPM.addPass(createFunctionToLoopPassAdaptor(
607       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
608 
609   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
610     auto PA = PreservedAnalyses::none();
611     PA.preserve<AAManager>();
612     PA.preserve<DominatorTreeAnalysis>();
613     // Not preserving the `LoopAnalysis`.
614     PA.preserve<LoopAnalysisManagerFunctionProxy>();
615     PA.preserve<ScalarEvolutionAnalysis>();
616     return PA;
617   }));
618   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
619   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
620   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
621   FPM.addPass(MFPHandle.getPass());
622   FPM.addPass(createFunctionToLoopPassAdaptor(
623       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
624 
625   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
626     auto PA = PreservedAnalyses::none();
627     PA.preserve<AAManager>();
628     PA.preserve<DominatorTreeAnalysis>();
629     PA.preserve<LoopAnalysis>();
630     // Not preserving the `LoopAnalysisManagerFunctionProxy`.
631     PA.preserve<ScalarEvolutionAnalysis>();
632     return PA;
633   }));
634   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
635   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
636   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
637   FPM.addPass(MFPHandle.getPass());
638   FPM.addPass(createFunctionToLoopPassAdaptor(
639       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
640 
641   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
642     auto PA = PreservedAnalyses::none();
643     PA.preserve<AAManager>();
644     PA.preserve<DominatorTreeAnalysis>();
645     PA.preserve<LoopAnalysis>();
646     PA.preserve<LoopAnalysisManagerFunctionProxy>();
647     // Not preserving `ScalarEvolutionAnalysis`.
648     return PA;
649   }));
650   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
651   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
652   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
653   FPM.addPass(MFPHandle.getPass());
654   FPM.addPass(createFunctionToLoopPassAdaptor(
655       RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
656 
657   // After all the churn on 'f', we'll compute the loop analysis results for
658   // 'g' once with a requires pass and then run our mock pass over g a bunch
659   // but just get cached results each time.
660   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
661   EXPECT_CALL(MFPHandle, run(HasName("g"), _)).Times(6);
662 
663   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
664   MPM.run(*M, MAM);
665 }
666 
667 TEST_F(LoopPassManagerTest, IndirectInvalidation) {
668   // We need two distinct analysis types and handles.
669   enum { A, B };
670   MockLoopAnalysisHandleTemplate<A> MLAHandleA;
671   MockLoopAnalysisHandleTemplate<B> MLAHandleB;
672   LAM.registerPass([&] { return MLAHandleA.getAnalysis(); });
673   LAM.registerPass([&] { return MLAHandleB.getAnalysis(); });
674   typedef decltype(MLAHandleA)::Analysis AnalysisA;
675   typedef decltype(MLAHandleB)::Analysis AnalysisB;
676 
677   // Set up AnalysisA to depend on our AnalysisB. For testing purposes we just
678   // need to get the AnalysisB results in AnalysisA's run method and check if
679   // AnalysisB gets invalidated in AnalysisA's invalidate method.
680   ON_CALL(MLAHandleA, run(_, _, _))
681       .WillByDefault(Invoke([&](Loop &L, LoopAnalysisManager &AM,
682                                 LoopStandardAnalysisResults &AR) {
683         (void)AM.getResult<AnalysisB>(L, AR);
684         return MLAHandleA.getResult();
685       }));
686   ON_CALL(MLAHandleA, invalidate(_, _, _))
687       .WillByDefault(Invoke([](Loop &L, const PreservedAnalyses &PA,
688                                LoopAnalysisManager::Invalidator &Inv) {
689         auto PAC = PA.getChecker<AnalysisA>();
690         return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Loop>>()) ||
691                Inv.invalidate<AnalysisB>(L, PA);
692       }));
693 
694   ::testing::InSequence MakeExpectationsSequenced;
695 
696   // Compute the analyses across all of 'f' first.
697   EXPECT_CALL(MLAHandleA, run(HasName("loop.0.0"), _, _));
698   EXPECT_CALL(MLAHandleB, run(HasName("loop.0.0"), _, _));
699   EXPECT_CALL(MLAHandleA, run(HasName("loop.0.1"), _, _));
700   EXPECT_CALL(MLAHandleB, run(HasName("loop.0.1"), _, _));
701   EXPECT_CALL(MLAHandleA, run(HasName("loop.0"), _, _));
702   EXPECT_CALL(MLAHandleB, run(HasName("loop.0"), _, _));
703 
704   // Now we invalidate AnalysisB (but not AnalysisA) for one of the loops and
705   // preserve everything for the rest. This in turn triggers that one loop to
706   // recompute both AnalysisB *and* AnalysisA if indirect invalidation is
707   // working.
708   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
709       .WillOnce(InvokeWithoutArgs([] {
710         auto PA = getLoopPassPreservedAnalyses();
711         // Specifically preserve AnalysisA so that it would survive if it
712         // didn't depend on AnalysisB.
713         PA.preserve<AnalysisA>();
714         return PA;
715       }));
716   // It happens that AnalysisB is invalidated first. That shouldn't matter
717   // though, and we should still call AnalysisA's invalidation.
718   EXPECT_CALL(MLAHandleB, invalidate(HasName("loop.0.0"), _, _));
719   EXPECT_CALL(MLAHandleA, invalidate(HasName("loop.0.0"), _, _));
720   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
721       .WillOnce(Invoke([](Loop &L, LoopAnalysisManager &AM,
722                           LoopStandardAnalysisResults &AR, LPMUpdater &) {
723         (void)AM.getResult<AnalysisA>(L, AR);
724         return PreservedAnalyses::all();
725       }));
726   EXPECT_CALL(MLAHandleA, run(HasName("loop.0.0"), _, _));
727   EXPECT_CALL(MLAHandleB, run(HasName("loop.0.0"), _, _));
728   // The rest of the loops should run and get cached results.
729   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
730       .Times(2)
731       .WillRepeatedly(Invoke([](Loop &L, LoopAnalysisManager &AM,
732                                 LoopStandardAnalysisResults &AR, LPMUpdater &) {
733         (void)AM.getResult<AnalysisA>(L, AR);
734         return PreservedAnalyses::all();
735       }));
736   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
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 
744   // The run over 'g' should be boring, with us just computing the analyses once
745   // up front and then running loop passes and getting cached results.
746   EXPECT_CALL(MLAHandleA, run(HasName("loop.g.0"), _, _));
747   EXPECT_CALL(MLAHandleB, run(HasName("loop.g.0"), _, _));
748   EXPECT_CALL(MLPHandle, run(HasName("loop.g.0"), _, _, _))
749       .Times(2)
750       .WillRepeatedly(Invoke([](Loop &L, LoopAnalysisManager &AM,
751                                 LoopStandardAnalysisResults &AR, LPMUpdater &) {
752         (void)AM.getResult<AnalysisA>(L, AR);
753         return PreservedAnalyses::all();
754       }));
755 
756   // Build the pipeline and run it.
757   ModulePassManager MPM(true);
758   FunctionPassManager FPM(true);
759   FPM.addPass(
760       createFunctionToLoopPassAdaptor(RequireAnalysisLoopPass<AnalysisA>()));
761   LoopPassManager LPM(true);
762   LPM.addPass(MLPHandle.getPass());
763   LPM.addPass(MLPHandle.getPass());
764   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
765   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
766   MPM.run(*M, MAM);
767 }
768 
769 TEST_F(LoopPassManagerTest, IndirectOuterPassInvalidation) {
770   typedef decltype(MLAHandle)::Analysis LoopAnalysis;
771 
772   MockFunctionAnalysisHandle MFAHandle;
773   FAM.registerPass([&] { return MFAHandle.getAnalysis(); });
774   typedef decltype(MFAHandle)::Analysis FunctionAnalysis;
775 
776   // Set up the loop analysis to depend on both the function and module
777   // analysis.
778   ON_CALL(MLAHandle, run(_, _, _))
779       .WillByDefault(Invoke([&](Loop &L, LoopAnalysisManager &AM,
780                                 LoopStandardAnalysisResults &AR) {
781         auto &FAMP = AM.getResult<FunctionAnalysisManagerLoopProxy>(L, AR);
782         Function &F = *L.getHeader()->getParent();
783         // This call will assert when trying to get the actual analysis if the
784         // FunctionAnalysis can be invalidated. Only check its existence.
785         // Alternatively, use FAM above, for the purposes of this unittest.
786         if (FAMP.cachedResultExists<FunctionAnalysis>(F))
787           FAMP.registerOuterAnalysisInvalidation<FunctionAnalysis,
788                                                  LoopAnalysis>();
789         return MLAHandle.getResult();
790       }));
791 
792   ::testing::InSequence MakeExpectationsSequenced;
793 
794   // Compute the analyses across all of 'f' first.
795   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
796       .WillOnce(Invoke([](Function &F, FunctionAnalysisManager &AM) {
797         // Force the computing of the function analysis so it is available in
798         // this function.
799         (void)AM.getResult<FunctionAnalysis>(F);
800         return PreservedAnalyses::all();
801       }));
802   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
803   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
804   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
805 
806   // Now invalidate the function analysis but preserve the loop analyses.
807   // This should trigger immediate invalidation of the loop analyses, despite
808   // the fact that they were preserved.
809   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
810     auto PA = getLoopPassPreservedAnalyses();
811     if (EnableMSSALoopDependency)
812       PA.preserve<MemorySSAAnalysis>();
813     PA.preserveSet<AllAnalysesOn<Loop>>();
814     return PA;
815   }));
816   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.0"), _, _));
817   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0.1"), _, _));
818   EXPECT_CALL(MLAHandle, invalidate(HasName("loop.0"), _, _));
819 
820   // And re-running a requires pass recomputes them.
821   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
822   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
823   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
824 
825   // When we run over 'g' we don't populate the cache with the function
826   // analysis.
827   EXPECT_CALL(MFPHandle, run(HasName("g"), _))
828       .WillOnce(Return(PreservedAnalyses::all()));
829   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
830 
831   // Which means that no extra invalidation occurs and cached values are used.
832   EXPECT_CALL(MFPHandle, run(HasName("g"), _)).WillOnce(InvokeWithoutArgs([] {
833     auto PA = getLoopPassPreservedAnalyses();
834     if (EnableMSSALoopDependency)
835       PA.preserve<MemorySSAAnalysis>();
836     PA.preserveSet<AllAnalysesOn<Loop>>();
837     return PA;
838   }));
839 
840   // Build the pipeline and run it.
841   ModulePassManager MPM(true);
842   FunctionPassManager FPM(true);
843   FPM.addPass(MFPHandle.getPass());
844   FPM.addPass(
845       createFunctionToLoopPassAdaptor(RequireAnalysisLoopPass<LoopAnalysis>()));
846   FPM.addPass(MFPHandle.getPass());
847   FPM.addPass(
848       createFunctionToLoopPassAdaptor(RequireAnalysisLoopPass<LoopAnalysis>()));
849   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
850   MPM.run(*M, MAM);
851 }
852 
853 TEST_F(LoopPassManagerTest, LoopChildInsertion) {
854   // Super boring module with three loops in a single loop nest.
855   M = parseIR(Context, "define void @f(i1* %ptr) {\n"
856                        "entry:\n"
857                        "  br label %loop.0\n"
858                        "loop.0:\n"
859                        "  %cond.0 = load volatile i1, i1* %ptr\n"
860                        "  br i1 %cond.0, label %loop.0.0.ph, label %end\n"
861                        "loop.0.0.ph:\n"
862                        "  br label %loop.0.0\n"
863                        "loop.0.0:\n"
864                        "  %cond.0.0 = load volatile i1, i1* %ptr\n"
865                        "  br i1 %cond.0.0, label %loop.0.0, label %loop.0.1.ph\n"
866                        "loop.0.1.ph:\n"
867                        "  br label %loop.0.1\n"
868                        "loop.0.1:\n"
869                        "  %cond.0.1 = load volatile i1, i1* %ptr\n"
870                        "  br i1 %cond.0.1, label %loop.0.1, label %loop.0.2.ph\n"
871                        "loop.0.2.ph:\n"
872                        "  br label %loop.0.2\n"
873                        "loop.0.2:\n"
874                        "  %cond.0.2 = load volatile i1, i1* %ptr\n"
875                        "  br i1 %cond.0.2, label %loop.0.2, label %loop.0.latch\n"
876                        "loop.0.latch:\n"
877                        "  br label %loop.0\n"
878                        "end:\n"
879                        "  ret void\n"
880                        "}\n");
881 
882   // Build up variables referring into the IR so we can rewrite it below
883   // easily.
884   Function &F = *M->begin();
885   ASSERT_THAT(F, HasName("f"));
886   Argument &Ptr = *F.arg_begin();
887   auto BBI = F.begin();
888   BasicBlock &EntryBB = *BBI++;
889   ASSERT_THAT(EntryBB, HasName("entry"));
890   BasicBlock &Loop0BB = *BBI++;
891   ASSERT_THAT(Loop0BB, HasName("loop.0"));
892   BasicBlock &Loop00PHBB = *BBI++;
893   ASSERT_THAT(Loop00PHBB, HasName("loop.0.0.ph"));
894   BasicBlock &Loop00BB = *BBI++;
895   ASSERT_THAT(Loop00BB, HasName("loop.0.0"));
896   BasicBlock &Loop01PHBB = *BBI++;
897   ASSERT_THAT(Loop01PHBB, HasName("loop.0.1.ph"));
898   BasicBlock &Loop01BB = *BBI++;
899   ASSERT_THAT(Loop01BB, HasName("loop.0.1"));
900   BasicBlock &Loop02PHBB = *BBI++;
901   ASSERT_THAT(Loop02PHBB, HasName("loop.0.2.ph"));
902   BasicBlock &Loop02BB = *BBI++;
903   ASSERT_THAT(Loop02BB, HasName("loop.0.2"));
904   BasicBlock &Loop0LatchBB = *BBI++;
905   ASSERT_THAT(Loop0LatchBB, HasName("loop.0.latch"));
906   BasicBlock &EndBB = *BBI++;
907   ASSERT_THAT(EndBB, HasName("end"));
908   ASSERT_THAT(BBI, F.end());
909   auto CreateCondBr = [&](BasicBlock *TrueBB, BasicBlock *FalseBB,
910                           const char *Name, BasicBlock *BB) {
911     auto *Cond = new LoadInst(Type::getInt1Ty(Context), &Ptr, Name,
912                               /*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(Type::getInt1Ty(Context), &Ptr, Name,
1115                               /*isVolatile*/ true, BB);
1116     BranchInst::Create(TrueBB, FalseBB, Cond, BB);
1117   };
1118 
1119   // Build the pass managers and register our pipeline. We build a single loop
1120   // pass pipeline consisting of three mock pass runs over each loop. After
1121   // this we run both domtree and loop verification passes to make sure that
1122   // the IR remained valid during our mutations.
1123   ModulePassManager MPM(true);
1124   FunctionPassManager FPM(true);
1125   LoopPassManager LPM(true);
1126   LPM.addPass(MLPHandle.getPass());
1127   LPM.addPass(MLPHandle.getPass());
1128   LPM.addPass(MLPHandle.getPass());
1129   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
1130   FPM.addPass(DominatorTreeVerifierPass());
1131   FPM.addPass(LoopVerifierPass());
1132   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
1133 
1134   // All the visit orders are deterministic, so we use simple fully order
1135   // expectations.
1136   ::testing::InSequence MakeExpectationsSequenced;
1137 
1138   // We run loop passes three times over each of the loops.
1139   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1140       .WillOnce(Invoke(getLoopAnalysisResult));
1141   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
1142 
1143   // On the second run, we insert a sibling loop.
1144   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1145       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
1146                            LoopStandardAnalysisResults &AR,
1147                            LPMUpdater &Updater) {
1148         auto *NewLoop = AR.LI.AllocateLoop();
1149         L.getParentLoop()->addChildLoop(NewLoop);
1150         auto *NewLoop01PHBB = BasicBlock::Create(Context, "loop.0.1.ph", &F, &Loop02PHBB);
1151         auto *NewLoop01BB = BasicBlock::Create(Context, "loop.0.1", &F, &Loop02PHBB);
1152         BranchInst::Create(NewLoop01BB, NewLoop01PHBB);
1153         CreateCondBr(&Loop02PHBB, NewLoop01BB, "cond.0.1", NewLoop01BB);
1154         Loop00BB.getTerminator()->replaceUsesOfWith(&Loop02PHBB, NewLoop01PHBB);
1155         AR.DT.addNewBlock(NewLoop01PHBB, &Loop00BB);
1156         auto *NewDTNode = AR.DT.addNewBlock(NewLoop01BB, NewLoop01PHBB);
1157         AR.DT.changeImmediateDominator(AR.DT[&Loop02PHBB], NewDTNode);
1158         EXPECT_TRUE(AR.DT.verify());
1159         L.getParentLoop()->addBasicBlockToLoop(NewLoop01PHBB, AR.LI);
1160         NewLoop->addBasicBlockToLoop(NewLoop01BB, AR.LI);
1161         L.getParentLoop()->verifyLoop();
1162         Updater.addSiblingLoops({NewLoop});
1163         return PreservedAnalyses::all();
1164       }));
1165   // We finish processing this loop as sibling loops don't perturb the
1166   // postorder walk.
1167   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1168       .WillOnce(Invoke(getLoopAnalysisResult));
1169 
1170   // We visit the inserted sibling next.
1171   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1172       .WillOnce(Invoke(getLoopAnalysisResult));
1173   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
1174   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1175       .Times(2)
1176       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1177 
1178   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1179       .WillOnce(Invoke(getLoopAnalysisResult));
1180   EXPECT_CALL(MLAHandle, run(HasName("loop.0.2"), _, _));
1181   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1182       .WillOnce(Invoke(getLoopAnalysisResult));
1183   // Next, on the third pass run on the last inner loop we add more new
1184   // siblings, more than one, and one with nested child loops. By doing this at
1185   // the end we make sure that edge case works well.
1186   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1187       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
1188                            LoopStandardAnalysisResults &AR,
1189                            LPMUpdater &Updater) {
1190         Loop *NewLoops[] = {AR.LI.AllocateLoop(), AR.LI.AllocateLoop(),
1191                             AR.LI.AllocateLoop()};
1192         L.getParentLoop()->addChildLoop(NewLoops[0]);
1193         L.getParentLoop()->addChildLoop(NewLoops[1]);
1194         NewLoops[1]->addChildLoop(NewLoops[2]);
1195         auto *NewLoop03PHBB =
1196             BasicBlock::Create(Context, "loop.0.3.ph", &F, &Loop0LatchBB);
1197         auto *NewLoop03BB =
1198             BasicBlock::Create(Context, "loop.0.3", &F, &Loop0LatchBB);
1199         auto *NewLoop04PHBB =
1200             BasicBlock::Create(Context, "loop.0.4.ph", &F, &Loop0LatchBB);
1201         auto *NewLoop04BB =
1202             BasicBlock::Create(Context, "loop.0.4", &F, &Loop0LatchBB);
1203         auto *NewLoop040PHBB =
1204             BasicBlock::Create(Context, "loop.0.4.0.ph", &F, &Loop0LatchBB);
1205         auto *NewLoop040BB =
1206             BasicBlock::Create(Context, "loop.0.4.0", &F, &Loop0LatchBB);
1207         auto *NewLoop04LatchBB =
1208             BasicBlock::Create(Context, "loop.0.4.latch", &F, &Loop0LatchBB);
1209         Loop02BB.getTerminator()->replaceUsesOfWith(&Loop0LatchBB, NewLoop03PHBB);
1210         BranchInst::Create(NewLoop03BB, NewLoop03PHBB);
1211         CreateCondBr(NewLoop04PHBB, NewLoop03BB, "cond.0.3", NewLoop03BB);
1212         BranchInst::Create(NewLoop04BB, NewLoop04PHBB);
1213         CreateCondBr(&Loop0LatchBB, NewLoop040PHBB, "cond.0.4", NewLoop04BB);
1214         BranchInst::Create(NewLoop040BB, NewLoop040PHBB);
1215         CreateCondBr(NewLoop04LatchBB, NewLoop040BB, "cond.0.4.0", NewLoop040BB);
1216         BranchInst::Create(NewLoop04BB, NewLoop04LatchBB);
1217         AR.DT.addNewBlock(NewLoop03PHBB, &Loop02BB);
1218         AR.DT.addNewBlock(NewLoop03BB, NewLoop03PHBB);
1219         AR.DT.addNewBlock(NewLoop04PHBB, NewLoop03BB);
1220         auto *NewDTNode = AR.DT.addNewBlock(NewLoop04BB, NewLoop04PHBB);
1221         AR.DT.changeImmediateDominator(AR.DT[&Loop0LatchBB], NewDTNode);
1222         AR.DT.addNewBlock(NewLoop040PHBB, NewLoop04BB);
1223         AR.DT.addNewBlock(NewLoop040BB, NewLoop040PHBB);
1224         AR.DT.addNewBlock(NewLoop04LatchBB, NewLoop040BB);
1225         EXPECT_TRUE(AR.DT.verify());
1226         L.getParentLoop()->addBasicBlockToLoop(NewLoop03PHBB, AR.LI);
1227         NewLoops[0]->addBasicBlockToLoop(NewLoop03BB, AR.LI);
1228         L.getParentLoop()->addBasicBlockToLoop(NewLoop04PHBB, AR.LI);
1229         NewLoops[1]->addBasicBlockToLoop(NewLoop04BB, AR.LI);
1230         NewLoops[1]->addBasicBlockToLoop(NewLoop040PHBB, AR.LI);
1231         NewLoops[2]->addBasicBlockToLoop(NewLoop040BB, AR.LI);
1232         NewLoops[1]->addBasicBlockToLoop(NewLoop04LatchBB, AR.LI);
1233         L.getParentLoop()->verifyLoop();
1234         Updater.addSiblingLoops({NewLoops[0], NewLoops[1]});
1235         return PreservedAnalyses::all();
1236       }));
1237 
1238   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1239       .WillOnce(Invoke(getLoopAnalysisResult));
1240   EXPECT_CALL(MLAHandle, run(HasName("loop.0.3"), _, _));
1241   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1242       .Times(2)
1243       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1244 
1245   // Note that we need to visit the inner loop of this added sibling before the
1246   // sibling itself!
1247   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4.0"), _, _, _))
1248       .WillOnce(Invoke(getLoopAnalysisResult));
1249   EXPECT_CALL(MLAHandle, run(HasName("loop.0.4.0"), _, _));
1250   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4.0"), _, _, _))
1251       .Times(2)
1252       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1253 
1254   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4"), _, _, _))
1255       .WillOnce(Invoke(getLoopAnalysisResult));
1256   EXPECT_CALL(MLAHandle, run(HasName("loop.0.4"), _, _));
1257   EXPECT_CALL(MLPHandle, run(HasName("loop.0.4"), _, _, _))
1258       .Times(2)
1259       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1260 
1261   // And only now do we visit the outermost loop of the nest.
1262   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1263       .WillOnce(Invoke(getLoopAnalysisResult));
1264   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
1265   // On the second pass, we add sibling loops which become new top-level loops.
1266   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1267       .WillOnce(Invoke([&](Loop &L, LoopAnalysisManager &AM,
1268                            LoopStandardAnalysisResults &AR,
1269                            LPMUpdater &Updater) {
1270         auto *NewLoop = AR.LI.AllocateLoop();
1271         AR.LI.addTopLevelLoop(NewLoop);
1272         auto *NewLoop1PHBB = BasicBlock::Create(Context, "loop.1.ph", &F, &Loop2BB);
1273         auto *NewLoop1BB = BasicBlock::Create(Context, "loop.1", &F, &Loop2BB);
1274         BranchInst::Create(NewLoop1BB, NewLoop1PHBB);
1275         CreateCondBr(&Loop2PHBB, NewLoop1BB, "cond.1", NewLoop1BB);
1276         Loop0BB.getTerminator()->replaceUsesOfWith(&Loop2PHBB, NewLoop1PHBB);
1277         AR.DT.addNewBlock(NewLoop1PHBB, &Loop0BB);
1278         auto *NewDTNode = AR.DT.addNewBlock(NewLoop1BB, NewLoop1PHBB);
1279         AR.DT.changeImmediateDominator(AR.DT[&Loop2PHBB], NewDTNode);
1280         EXPECT_TRUE(AR.DT.verify());
1281         NewLoop->addBasicBlockToLoop(NewLoop1BB, AR.LI);
1282         NewLoop->verifyLoop();
1283         Updater.addSiblingLoops({NewLoop});
1284         return PreservedAnalyses::all();
1285       }));
1286   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1287       .WillOnce(Invoke(getLoopAnalysisResult));
1288 
1289   EXPECT_CALL(MLPHandle, run(HasName("loop.1"), _, _, _))
1290       .WillOnce(Invoke(getLoopAnalysisResult));
1291   EXPECT_CALL(MLAHandle, run(HasName("loop.1"), _, _));
1292   EXPECT_CALL(MLPHandle, run(HasName("loop.1"), _, _, _))
1293       .Times(2)
1294       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1295 
1296   EXPECT_CALL(MLPHandle, run(HasName("loop.2"), _, _, _))
1297       .WillOnce(Invoke(getLoopAnalysisResult));
1298   EXPECT_CALL(MLAHandle, run(HasName("loop.2"), _, _));
1299   EXPECT_CALL(MLPHandle, run(HasName("loop.2"), _, _, _))
1300       .Times(2)
1301       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1302 
1303   // Now that all the expected actions are registered, run the pipeline over
1304   // our module. All of our expectations are verified when the test finishes.
1305   MPM.run(*M, MAM);
1306 }
1307 
1308 TEST_F(LoopPassManagerTest, LoopDeletion) {
1309   // Build a module with a single loop nest that contains one outer loop with
1310   // three subloops, and one of those with its own subloop. We will
1311   // incrementally delete all of these to test different deletion scenarios.
1312   M = parseIR(Context, "define void @f(i1* %ptr) {\n"
1313                        "entry:\n"
1314                        "  br label %loop.0\n"
1315                        "loop.0:\n"
1316                        "  %cond.0 = load volatile i1, i1* %ptr\n"
1317                        "  br i1 %cond.0, label %loop.0.0.ph, label %end\n"
1318                        "loop.0.0.ph:\n"
1319                        "  br label %loop.0.0\n"
1320                        "loop.0.0:\n"
1321                        "  %cond.0.0 = load volatile i1, i1* %ptr\n"
1322                        "  br i1 %cond.0.0, label %loop.0.0, label %loop.0.1.ph\n"
1323                        "loop.0.1.ph:\n"
1324                        "  br label %loop.0.1\n"
1325                        "loop.0.1:\n"
1326                        "  %cond.0.1 = load volatile i1, i1* %ptr\n"
1327                        "  br i1 %cond.0.1, label %loop.0.1, label %loop.0.2.ph\n"
1328                        "loop.0.2.ph:\n"
1329                        "  br label %loop.0.2\n"
1330                        "loop.0.2:\n"
1331                        "  %cond.0.2 = load volatile i1, i1* %ptr\n"
1332                        "  br i1 %cond.0.2, label %loop.0.2.0.ph, label %loop.0.latch\n"
1333                        "loop.0.2.0.ph:\n"
1334                        "  br label %loop.0.2.0\n"
1335                        "loop.0.2.0:\n"
1336                        "  %cond.0.2.0 = load volatile i1, i1* %ptr\n"
1337                        "  br i1 %cond.0.2.0, label %loop.0.2.0, label %loop.0.2.latch\n"
1338                        "loop.0.2.latch:\n"
1339                        "  br label %loop.0.2\n"
1340                        "loop.0.latch:\n"
1341                        "  br label %loop.0\n"
1342                        "end:\n"
1343                        "  ret void\n"
1344                        "}\n");
1345 
1346   // Build up variables referring into the IR so we can rewrite it below
1347   // easily.
1348   Function &F = *M->begin();
1349   ASSERT_THAT(F, HasName("f"));
1350   Argument &Ptr = *F.arg_begin();
1351   auto BBI = F.begin();
1352   BasicBlock &EntryBB = *BBI++;
1353   ASSERT_THAT(EntryBB, HasName("entry"));
1354   BasicBlock &Loop0BB = *BBI++;
1355   ASSERT_THAT(Loop0BB, HasName("loop.0"));
1356   BasicBlock &Loop00PHBB = *BBI++;
1357   ASSERT_THAT(Loop00PHBB, HasName("loop.0.0.ph"));
1358   BasicBlock &Loop00BB = *BBI++;
1359   ASSERT_THAT(Loop00BB, HasName("loop.0.0"));
1360   BasicBlock &Loop01PHBB = *BBI++;
1361   ASSERT_THAT(Loop01PHBB, HasName("loop.0.1.ph"));
1362   BasicBlock &Loop01BB = *BBI++;
1363   ASSERT_THAT(Loop01BB, HasName("loop.0.1"));
1364   BasicBlock &Loop02PHBB = *BBI++;
1365   ASSERT_THAT(Loop02PHBB, HasName("loop.0.2.ph"));
1366   BasicBlock &Loop02BB = *BBI++;
1367   ASSERT_THAT(Loop02BB, HasName("loop.0.2"));
1368   BasicBlock &Loop020PHBB = *BBI++;
1369   ASSERT_THAT(Loop020PHBB, HasName("loop.0.2.0.ph"));
1370   BasicBlock &Loop020BB = *BBI++;
1371   ASSERT_THAT(Loop020BB, HasName("loop.0.2.0"));
1372   BasicBlock &Loop02LatchBB = *BBI++;
1373   ASSERT_THAT(Loop02LatchBB, HasName("loop.0.2.latch"));
1374   BasicBlock &Loop0LatchBB = *BBI++;
1375   ASSERT_THAT(Loop0LatchBB, HasName("loop.0.latch"));
1376   BasicBlock &EndBB = *BBI++;
1377   ASSERT_THAT(EndBB, HasName("end"));
1378   ASSERT_THAT(BBI, F.end());
1379 
1380   // Helper to do the actual deletion of a loop. We directly encode this here
1381   // to isolate ourselves from the rest of LLVM and for simplicity. Here we can
1382   // egregiously cheat based on knowledge of the test case. For example, we
1383   // have no PHI nodes and there is always a single i-dom.
1384   auto EraseLoop = [](Loop &L, BasicBlock &IDomBB,
1385                       LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1386     assert(L.empty() && "Can only delete leaf loops with this routine!");
1387     SmallVector<BasicBlock *, 4> LoopBBs(L.block_begin(), L.block_end());
1388     Updater.markLoopAsDeleted(L, L.getName());
1389     IDomBB.getTerminator()->replaceUsesOfWith(L.getHeader(),
1390                                               L.getUniqueExitBlock());
1391     for (BasicBlock *LoopBB : LoopBBs) {
1392       SmallVector<DomTreeNode *, 4> ChildNodes(AR.DT[LoopBB]->begin(),
1393                                                AR.DT[LoopBB]->end());
1394       for (DomTreeNode *ChildNode : ChildNodes)
1395         AR.DT.changeImmediateDominator(ChildNode, AR.DT[&IDomBB]);
1396       AR.DT.eraseNode(LoopBB);
1397       AR.LI.removeBlock(LoopBB);
1398       LoopBB->dropAllReferences();
1399     }
1400     for (BasicBlock *LoopBB : LoopBBs)
1401       LoopBB->eraseFromParent();
1402 
1403     AR.LI.erase(&L);
1404   };
1405 
1406   // Build up the pass managers.
1407   ModulePassManager MPM(true);
1408   FunctionPassManager FPM(true);
1409   // We run several loop pass pipelines across the loop nest, but they all take
1410   // the same form of three mock pass runs in a loop pipeline followed by
1411   // domtree and loop verification. We use a lambda to stamp this out each
1412   // time.
1413   auto AddLoopPipelineAndVerificationPasses = [&] {
1414     LoopPassManager LPM(true);
1415     LPM.addPass(MLPHandle.getPass());
1416     LPM.addPass(MLPHandle.getPass());
1417     LPM.addPass(MLPHandle.getPass());
1418     FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
1419     FPM.addPass(DominatorTreeVerifierPass());
1420     FPM.addPass(LoopVerifierPass());
1421   };
1422 
1423   // All the visit orders are deterministic so we use simple fully order
1424   // expectations.
1425   ::testing::InSequence MakeExpectationsSequenced;
1426 
1427   // We run the loop pipeline with three passes over each of the loops. When
1428   // running over the middle loop, the second pass in the pipeline deletes it.
1429   // This should prevent the third pass from visiting it but otherwise leave
1430   // the process unimpacted.
1431   AddLoopPipelineAndVerificationPasses();
1432   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1433       .WillOnce(Invoke(getLoopAnalysisResult));
1434   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
1435   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1436       .Times(2)
1437       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1438 
1439   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1440       .WillOnce(Invoke(getLoopAnalysisResult));
1441   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
1442   EXPECT_CALL(MLPHandle, run(HasName("loop.0.1"), _, _, _))
1443       .WillOnce(
1444           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1445                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1446             Loop *ParentL = L.getParentLoop();
1447             AR.SE.forgetLoop(&L);
1448             EraseLoop(L, Loop01PHBB, AR, Updater);
1449             ParentL->verifyLoop();
1450             return PreservedAnalyses::all();
1451           }));
1452 
1453   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2.0"), _, _, _))
1454       .WillOnce(Invoke(getLoopAnalysisResult));
1455   EXPECT_CALL(MLAHandle, run(HasName("loop.0.2.0"), _, _));
1456   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2.0"), _, _, _))
1457       .Times(2)
1458       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1459 
1460   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1461       .WillOnce(Invoke(getLoopAnalysisResult));
1462   EXPECT_CALL(MLAHandle, run(HasName("loop.0.2"), _, _));
1463   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1464       .Times(2)
1465       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1466 
1467   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1468       .WillOnce(Invoke(getLoopAnalysisResult));
1469   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
1470   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1471       .Times(2)
1472       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1473 
1474   // Run the loop pipeline again. This time we delete the last loop, which
1475   // contains a nested loop within it and insert a new loop into the nest. This
1476   // makes sure we can handle nested loop deletion.
1477   AddLoopPipelineAndVerificationPasses();
1478   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1479       .Times(3)
1480       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1481 
1482   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2.0"), _, _, _))
1483       .Times(3)
1484       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1485 
1486   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1487       .WillOnce(Invoke(getLoopAnalysisResult));
1488   BasicBlock *NewLoop03PHBB;
1489   EXPECT_CALL(MLPHandle, run(HasName("loop.0.2"), _, _, _))
1490       .WillOnce(
1491           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1492                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1493             AR.SE.forgetLoop(*L.begin());
1494             EraseLoop(**L.begin(), Loop020PHBB, AR, Updater);
1495 
1496             auto *ParentL = L.getParentLoop();
1497             AR.SE.forgetLoop(&L);
1498             EraseLoop(L, Loop02PHBB, AR, Updater);
1499 
1500             // Now insert a new sibling loop.
1501             auto *NewSibling = AR.LI.AllocateLoop();
1502             ParentL->addChildLoop(NewSibling);
1503             NewLoop03PHBB =
1504                 BasicBlock::Create(Context, "loop.0.3.ph", &F, &Loop0LatchBB);
1505             auto *NewLoop03BB =
1506                 BasicBlock::Create(Context, "loop.0.3", &F, &Loop0LatchBB);
1507             BranchInst::Create(NewLoop03BB, NewLoop03PHBB);
1508             auto *Cond =
1509                 new LoadInst(Type::getInt1Ty(Context), &Ptr, "cond.0.3",
1510                              /*isVolatile*/ true, NewLoop03BB);
1511             BranchInst::Create(&Loop0LatchBB, NewLoop03BB, Cond, NewLoop03BB);
1512             Loop02PHBB.getTerminator()->replaceUsesOfWith(&Loop0LatchBB,
1513                                                           NewLoop03PHBB);
1514             AR.DT.addNewBlock(NewLoop03PHBB, &Loop02PHBB);
1515             AR.DT.addNewBlock(NewLoop03BB, NewLoop03PHBB);
1516             AR.DT.changeImmediateDominator(AR.DT[&Loop0LatchBB],
1517                                            AR.DT[NewLoop03BB]);
1518             EXPECT_TRUE(AR.DT.verify());
1519             ParentL->addBasicBlockToLoop(NewLoop03PHBB, AR.LI);
1520             NewSibling->addBasicBlockToLoop(NewLoop03BB, AR.LI);
1521             NewSibling->verifyLoop();
1522             ParentL->verifyLoop();
1523             Updater.addSiblingLoops({NewSibling});
1524             return PreservedAnalyses::all();
1525           }));
1526 
1527   // To respect our inner-to-outer traversal order, we must visit the
1528   // newly-inserted sibling of the loop we just deleted before we visit the
1529   // outer loop. When we do so, this must compute a fresh analysis result, even
1530   // though our new loop has the same pointer value as the loop we deleted.
1531   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1532       .WillOnce(Invoke(getLoopAnalysisResult));
1533   EXPECT_CALL(MLAHandle, run(HasName("loop.0.3"), _, _));
1534   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1535       .Times(2)
1536       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1537 
1538   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1539       .Times(3)
1540       .WillRepeatedly(Invoke(getLoopAnalysisResult));
1541 
1542   // In the final loop pipeline run we delete every loop, including the last
1543   // loop of the nest. We do this again in the second pass in the pipeline, and
1544   // as a consequence we never make it to three runs on any loop. We also cover
1545   // deleting multiple loops in a single pipeline, deleting the first loop and
1546   // deleting the (last) top level loop.
1547   AddLoopPipelineAndVerificationPasses();
1548   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1549       .WillOnce(Invoke(getLoopAnalysisResult));
1550   EXPECT_CALL(MLPHandle, run(HasName("loop.0.0"), _, _, _))
1551       .WillOnce(
1552           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1553                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1554             AR.SE.forgetLoop(&L);
1555             EraseLoop(L, Loop00PHBB, AR, Updater);
1556             return PreservedAnalyses::all();
1557           }));
1558 
1559   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1560       .WillOnce(Invoke(getLoopAnalysisResult));
1561   EXPECT_CALL(MLPHandle, run(HasName("loop.0.3"), _, _, _))
1562       .WillOnce(
1563           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1564                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1565             AR.SE.forgetLoop(&L);
1566             EraseLoop(L, *NewLoop03PHBB, AR, Updater);
1567             return PreservedAnalyses::all();
1568           }));
1569 
1570   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1571       .WillOnce(Invoke(getLoopAnalysisResult));
1572   EXPECT_CALL(MLPHandle, run(HasName("loop.0"), _, _, _))
1573       .WillOnce(
1574           Invoke([&](Loop &L, LoopAnalysisManager &AM,
1575                      LoopStandardAnalysisResults &AR, LPMUpdater &Updater) {
1576             AR.SE.forgetLoop(&L);
1577             EraseLoop(L, EntryBB, AR, Updater);
1578             return PreservedAnalyses::all();
1579           }));
1580 
1581   // Add the function pass pipeline now that it is fully built up and run it
1582   // over the module's one function.
1583   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
1584   MPM.run(*M, MAM);
1585 }
1586 }
1587