[llvm] fdf2259 - [NFC] Comment in MLInlineAdvisor as to why use std::map for FPICache

[Mircea Trofin via llvm-commits]

Author: Mircea Trofin
Date: 2022-11-07T11:10:58-08:00
New Revision: fdf22598862a072fe6136bc0484b5747e68da20d

URL: https://github.com/llvm/llvm-project/commit/fdf22598862a072fe6136bc0484b5747e68da20d
DIFF: https://github.com/llvm/llvm-project/commit/fdf22598862a072fe6136bc0484b5747e68da20d.diff

LOG: [NFC] Comment in MLInlineAdvisor as to why use  std::map for FPICache

Added: 
    

Modified: 
    llvm/include/llvm/Analysis/MLInlineAdvisor.h

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Analysis/MLInlineAdvisor.h b/llvm/include/llvm/Analysis/MLInlineAdvisor.h
index 3db948d365c7..7535464e0710 100644
--- a/llvm/include/llvm/Analysis/MLInlineAdvisor.h
+++ b/llvm/include/llvm/Analysis/MLInlineAdvisor.h
@@ -69,6 +69,9 @@ class MLInlineAdvisor : public InlineAdvisor {
   getSkipAdviceIfUnreachableCallsite(CallBase &CB);
   void print(raw_ostream &OS) const override;
 
+  // Using std::map to benefit from its iterator / reference non-invalidating
+  // semantics, which make it easy to use `getCachedFPI` results from multiple
+  // calls without needing to copy to avoid invalidation effects.
   mutable std::map<const Function *, FunctionPropertiesInfo> FPICache;
 
   LazyCallGraph &CG;