[PATCH] D109548: Make llvm.launder.invariant.group writeonly

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks created this revision.
aeubanks added a reviewer: Prazek.
Herald added subscribers: ormris, okura, kuter.
aeubanks requested review of this revision.
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Herald added subscribers: llvm-commits, jdoerfert.
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-fstrict-vtable-pointers causes many functions to no longer be
considered writeonly. This is because basic-aa thinks launder may read
from the pointer operand.

>From the LangRef on writeonly:
If a writeonly function reads memory visible to the program, or has
other side-effects, the behavior is undefined. If a function reads from
a writeonly pointer argument, the behavior is undefined.

launder fits this criteria.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D109548

Files:
  llvm/include/llvm/IR/Intrinsics.td
  llvm/test/Other/invariant.group.ll
  llvm/test/Transforms/Attributor/nocapture-1.ll
  llvm/test/Transforms/FunctionAttrs/launder.ll

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