[PATCH] D109888: Bitcast wrapped in a call obscures function attributes, pessimizing MemorySSA

[Antonio Frighetto via Phabricator via llvm-commits]

antoniofrighetto created this revision.
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A logic incompleteness may lead MemorySSA to be too conservative in its results. Specifically,
when dealing with a call of kind `call i32 bitcast (i1 (i1)* @test to i32 (i32)*)(i32 %1)`,
where function call `test` is declared with `readonly` attribute, the bitcast is not wrapped,
obscuring function attributes. Hence, some methods of CallBase (e.g., `doesNotReadMemory`)
could provide incomplete results. This issue was addressed with improved checks.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D109888

Files:
  llvm/lib/IR/Instructions.cpp
  llvm/test/Analysis/MemorySSA/call-bitcast.ll
  llvm/test/Transforms/Attributor/IPConstantProp/arg-count-mismatch.ll
  llvm/test/Transforms/Attributor/IPConstantProp/arg-type-mismatch.ll
  llvm/test/Transforms/Attributor/liveness.ll

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