[Inline] Make sure the InlineAdvisor is correctly cleared.

[mtrofin]

Summary

If another inlining session came after a ModuleInlinerWrapperPass, the
advisor alanysis would still be cached, but its Result would be cleared.
We need to clear both.

This addresses PR52118

[aeubanks]

llvm/include/llvm/Analysis/InlineAdvisor.h

231–232

this seems like it's reimplementing the invalidation.
can we get rid of clear() and use

bool invalidate(Module &, const PreservedAnalyses &PA,
                                 ModuleAnalysisManager::Invalidator &) {
  // Check whether the analysis has been explicitly invalidated. Otherwise, it's
  // stateless and remains preserved.
  auto PAC = PA.getChecker<InlineAdvisorAnalysis>();
  return !PAC.preservedWhenStateless();
}

?

llvm/lib/Transforms/IPO/Inliner.cpp

1053

can we

auto PA = PreservedAnalyses::all();
PA.abandon<>();
return PA;

instead? and add a comment

[mtrofin]

feedback

[mtrofin]

llvm/lib/Transforms/IPO/Inliner.cpp

1053

done. btw, the newpm tests (e.g. Other/new-pm-defaults, etc) need updating. I'll do it once everything else looks OK

(...which is really just me procrastinating)

[mtrofin]

Updated PM tests

llvm/include/llvm/Analysis/InlineAdvisor.h

 /// The InlineAdvisorAnalysis is a module pass because the InlineAdvisor
 /// needs to capture state right before inlining commences over a module.
 class InlineAdvisorAnalysis : public AnalysisInfoMixin<InlineAdvisorAnalysis> {
 public:
   static AnalysisKey Key;
   InlineAdvisorAnalysis() = default;
   struct Result {
     Result(Module &M, ModuleAnalysisManager &MAM) : M(M), MAM(MAM) {}
-    bool invalidate(Module &, const PreservedAnalyses &,
+    bool invalidate(Module &, const PreservedAnalyses &PA,
                     ModuleAnalysisManager::Invalidator &) {
-      // InlineAdvisor must be preserved across analysis invalidations.
-      return false;
+      // Check whether the analysis has been explicitly invalidated. Otherwise,
+      // it's stateless and remains preserved.
+      auto PAC = PA.getChecker<InlineAdvisorAnalysis>();
+      return !PAC.preservedWhenStateless();
     }
     bool tryCreate(InlineParams Params, InliningAdvisorMode Mode,
                    StringRef ReplayFile);
     InlineAdvisor *getAdvisor() const { return Advisor.get(); }
-    void clear() { Advisor.reset(); }
 
   private:
     Module &M;
     ModuleAnalysisManager &MAM;
     std::unique_ptr<InlineAdvisor> Advisor;
   };
 
   Result run(Module &M, ModuleAnalysisManager &MAM) { return Result(M, MAM); }
 };

llvm/lib/Transforms/IPO/Inliner.cpp

PreservedAnalyses ModuleInlinerWrapperPass::run(Module &M,
   // wrapper.
   if (MaxDevirtIterations == 0)
     MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(PM)));
   else
     MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(
         createDevirtSCCRepeatedPass(std::move(PM), MaxDevirtIterations)));
   MPM.run(M, MAM);
 
-  IAA.clear();
-
-  // The ModulePassManager has already taken care of invalidating analyses.
-  return PreservedAnalyses::all();
+  // Discard the InlineAdvisor, a subsequent inlining session should construct
+  // its own.
+  auto PA = PreservedAnalyses::all();
+  PA.abandon<InlineAdvisorAnalysis>();
+  return PA;
 }
 
 void InlinerPass::printPipeline(
     raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) {
   static_cast<PassInfoMixin<InlinerPass> *>(this)->printPipeline(
       OS, MapClassName2PassName);
   if (OnlyMandatory)
     OS << "<only-mandatory>";

llvm/test/Transforms/Inline/pr52118.ll

+; Test that the InlineAdvisor, upon being cleared, is re-created correctly.
+; RUN: opt -S -passes="default<O1>,cgscc(inline)" < %s | FileCheck %s
+
+define double @foo() local_unnamed_addr {
+entry:
+  ret double undef
+}
+
+; CHECK: @foo