[PATCH] D99118: [SROA] Speculate around PHIs: allow load to be in a unique-successor unique-predecessor block

[Roman Lebedev via Phabricator via llvm-commits]

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There's `2009-02-20-InstCombine-SROA.ll` InstCombine test that uses SROA,
and it breaks if i change InstCombine to split up `inttoptr` into `bitcast(inttoptr)`.
The cause is, if we have a PHI and a load of that PHI, InstCombine may sink the load
into unique successor block. And `isSafePHIToSpeculate()` bails out on that.

So extend `isSafePHIToSpeculate()` to support traversing through such blocks.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D99118

Files:
  llvm/lib/Transforms/Scalar/SROA.cpp
  llvm/test/Transforms/SROA/2009-02-20-InstCombine-SROA.ll
  llvm/test/Transforms/SROA/phi-with-duplicate-pred.ll

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