[PATCH] D102615: [LoopDeletion] Break backedge if we can prove that the loop is exited on 1st iteration

[Mikael Holmén via Phabricator via llvm-commits]

uabelho added a comment.

In D102615#2781330 <https://reviews.llvm.org/D102615#2781330>, @mkazantsev wrote:

> @uabelho Looking into your example, I don't think enough evidence it's a miscompile. Your test has non-side-effecting infinite loop, which has undefined behavior. So it's legal to make the replacement. Can you construct the example without an infinite loop?

Hm, is it really? For input 1, 1, 0 I think it terminates and return the value 20 after executing this path:

  entry -> if.end -> bb2 -> bb4 -> bb12 -> bb2 -> bb4 ->bb13 -> ret

?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D102615/new/

https://reviews.llvm.org/D102615