[PATCH] D38960: [Local] Fix a bug in the domtree update logic for MergeBasicBlockIntoOnlyPred.

[Balaram Makam via Phabricator via llvm-commits]

bmakam added a comment.

In https://reviews.llvm.org/D38960#898701, @kuhar wrote:

> > For some irreducible CFG the domtree nodes might be dead, do not update domtree for dead nodes.
>
> Can you show some example of such CFG and add a comment explaining this check?
>
> DomTree::getNode return nullptr only for forward-unreachable CFG nodes.


I found this bug while testing https://reviews.llvm.org/D37343. When https://reviews.llvm.org/D37343 is applied, test/Transforms/CodeGenPrepare/2008-11-24-RAUW-Self.ll will crash because of this.


https://reviews.llvm.org/D38960