[PATCH] D130713: [AA] Do not track Must in ModRefInfo

[Nikita Popov via Phabricator via llvm-commits]

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getModRefInfo() queries currently track whether the result is a MustAlias on a best-effort basis. The only user of this functionality is the optimized memory access type in MemorySSA -- which in turn has no users. Given that this functionality has not found a user since it was introduced five years ago (in D38862 <https://reviews.llvm.org/D38862>), I think we should consider dropping it again.

The context is that I'm working to separate FunctionModRefBehavior to track mod/ref for different location kinds (like argmem or inaccessiblemem) separately, and the fact that ModRefInfo also has an unrelated Must flag makes this quite awkward, especially as this means that NoModRef is not a zero value. If we want to retain the functionality, I would probably split ModRefInfo into a part that just contains the ModRef information, and a separate part tracking the Must flag.


https://reviews.llvm.org/D130713

Files:
  llvm/include/llvm/Analysis/AliasAnalysis.h
  llvm/include/llvm/Analysis/MemorySSA.h
  llvm/lib/Analysis/AliasAnalysis.cpp
  llvm/lib/Analysis/AliasAnalysisEvaluator.cpp
  llvm/lib/Analysis/BasicAliasAnalysis.cpp
  llvm/lib/Analysis/GlobalsModRef.cpp
  llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
  llvm/lib/Analysis/MemorySSA.cpp
  llvm/test/Analysis/BasicAA/atomic-memory-intrinsics.ll
  llvm/test/Analysis/BasicAA/call-attrs.ll
  llvm/test/Analysis/BasicAA/cs-cs.ll
  llvm/test/Analysis/BasicAA/libfuncs.ll
  llvm/test/Analysis/MemorySSA/basicaa-memcpy.ll
  llvm/test/Analysis/MemorySSA/call-bitcast.ll
  llvm/test/Analysis/MemorySSA/optimize-use.ll
  llvm/test/Analysis/MemorySSA/phi-translation.ll
  llvm/test/Analysis/MemorySSA/print-walker.ll
  llvm/test/Analysis/MemorySSA/scalable-vec.ll
  llvm/unittests/Analysis/MemorySSATest.cpp

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