[all-commits] [llvm/llvm-project] 27e4af: [DSE] Don't remove nounwind invokes

[Heejin Ahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 27e4afcea71818ef2ceb0be109321b9595a8fba2
      https://github.com/llvm/llvm-project/commit/27e4afcea71818ef2ceb0be109321b9595a8fba2
  Author: Heejin Ahn <aheejin at gmail.com>
  Date:   2022-06-21 (Tue, 21 Jun 2022)

  Changed paths:
    M llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
    A llvm/test/Transforms/DeadStoreElimination/nounwind-invoke.ll

  Log Message:
  -----------
  [DSE] Don't remove nounwind invokes

For non-mem-intrinsic and non-lifetime `CallBase`s, the current
`isRemovable` function only checks if the `CallBase` 1. has no uses 2.
will return 3. does not throw:
https://github.com/llvm/llvm-project/blob/80fb7823367c1d105fcbc8f21b69205a0d68c859/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp#L1017

But we should also exclude invokes even in case they don't throw,
because they are terminators and thus cannot be removed. While it
doesn't seem to make much sense for `invoke`s to have an `nounwind`
target, this kind of code can be generated and is also valid bitcode.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D128224