[PATCH] D98843: [Evaluator] Look through invariant.group intrinsics

[Arthur Eubanks via Phabricator via llvm-commits]

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Turning on -fstrict-vtable-pointers in Chrome caused an extra global
initializer. Turns out that a llvm.strip.invariant.group intrinsic was
causing GlobalOpt to fail to step through some simple code.

We can treat *.invariant.group uses as simply their operand. This should
be safe because the Evaluator does not skip memory accesses due to
invariants.

However, we don't want to leak that we've ignored *.invariant.group
calls to users of Evaluator, so we bail out if we evaluate to a pointer
constant, since we may have looked through *.invariant.group calls.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D98843

Files:
  llvm/include/llvm/Transforms/Utils/Evaluator.h
  llvm/lib/Transforms/Utils/Evaluator.cpp
  llvm/test/Transforms/GlobalOpt/invariant.group.ll

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