[PATCH] D113644: [NFC][InlineAdvisor] Inform advisor when the module is invalidated

[Mircea Trofin via Phabricator via llvm-commits]

mtrofin created this revision.
mtrofin added reviewers: phosek, aeubanks.
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This avoids unnecessary re-calculation of module-wide features in the
MLInlineAdvisor. In cases where function passes don't invalidate
functions (and, thus, don't invalidate the module), but we re-process a
CGSCC, we currently refreshed module features unnecessarily. The
overhead of fetching cached results (albeit they weren't themselves
invalidated) was noticeable in certain modules' compilations.

We don't want to just invalidate the advisor object, though, via the
analysis manager, because we'd then need to re-create expensive state
(like the model evaluator in the ML 'development' mode).


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D113644

Files:
  llvm/include/llvm/Analysis/InlineAdvisor.h
  llvm/include/llvm/Analysis/MLInlineAdvisor.h
  llvm/lib/Analysis/MLInlineAdvisor.cpp


Index: llvm/lib/Analysis/MLInlineAdvisor.cpp
===================================================================
--- llvm/lib/Analysis/MLInlineAdvisor.cpp
+++ llvm/lib/Analysis/MLInlineAdvisor.cpp
@@ -116,6 +116,8 @@
 void MLInlineAdvisor::onPassEntry() {
   // Function passes executed between InlinerPass runs may have changed the
   // module-wide features.
+  if (!Invalid)
+    return;
   NodeCount = 0;
   EdgeCount = 0;
   for (auto &F : M)
@@ -123,6 +125,7 @@
       ++NodeCount;
       EdgeCount += getLocalCalls(F);
     }
+  Invalid = false;
 }
 
 int64_t MLInlineAdvisor::getLocalCalls(Function &F) {
Index: llvm/include/llvm/Analysis/MLInlineAdvisor.h
===================================================================
--- llvm/include/llvm/Analysis/MLInlineAdvisor.h
+++ llvm/include/llvm/Analysis/MLInlineAdvisor.h
@@ -38,6 +38,7 @@
   bool isForcedToStop() const { return ForceStop; }
   int64_t getLocalCalls(Function &F);
   const MLModelRunner &getModelRunner() const { return *ModelRunner.get(); }
+  void onModuleInvalidated() override { Invalid = true; }
 
 protected:
   std::unique_ptr<InlineAdvice> getAdviceImpl(CallBase &CB) override;
@@ -55,6 +56,7 @@
 private:
   int64_t getModuleIRSize() const;
 
+  bool Invalid = true;
   std::unique_ptr<CallGraph> CG;
 
   int64_t NodeCount = 0;
Index: llvm/include/llvm/Analysis/InlineAdvisor.h
===================================================================
--- llvm/include/llvm/Analysis/InlineAdvisor.h
+++ llvm/include/llvm/Analysis/InlineAdvisor.h
@@ -162,6 +162,12 @@
   /// to prepare for a partial update.
   virtual void onPassExit() {}
 
+  /// Called when the module is invalidated. We let the advisor implementation
+  /// decide what to refresh - in the case of the development mode
+  /// implementation, for example, we wouldn't want to delete the whole object
+  /// and need to re-load the model evaluator.
+  virtual void onModuleInvalidated() {}
+
 protected:
   InlineAdvisor(Module &M, FunctionAnalysisManager &FAM);
   virtual std::unique_ptr<InlineAdvice> getAdviceImpl(CallBase &CB) = 0;
@@ -226,6 +232,8 @@
     Result(Module &M, ModuleAnalysisManager &MAM) : M(M), MAM(MAM) {}
     bool invalidate(Module &, const PreservedAnalyses &PA,
                     ModuleAnalysisManager::Invalidator &) {
+      if (Advisor && !PA.areAllPreserved())
+        Advisor->onModuleInvalidated();
       // Check whether the analysis has been explicitly invalidated. Otherwise,
       // it's stateless and remains preserved.
       auto PAC = PA.getChecker<InlineAdvisorAnalysis>();


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