[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#2781150 <https://reviews.llvm.org/D102615#2781150>, @uabelho wrote:

> Just a heads up, I think I'm seeing a miscompile with this patch.
> I'll dig further and try to extract a reproducer.

Reproduce with:

  opt -loop-deletion loop-deletion.ll -S -o -

The bb12 -> bb2 back edge is replaced with a branch to unreachable which I think is wrong in this case.
(I made some comments in the input file showing how I think the back edge may be taken.)
F17048077: loop-deletion.ll <https://reviews.llvm.org/F17048077>


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https://reviews.llvm.org/D102615