[llvm] [GVN] Excluding dead blocks before full redundancy eliminations (PR #88556)

[Min-Yih Hsu via llvm-commits]

mshockwave wrote:

> Would it be possible / make sense to remove the assertion instead? As I understand it, doing a replacement with undef should be correct here, right?

Let me give it a try.

> 
> Looking at the commit that introduced the assertion ([3168ab3](https://github.com/llvm/llvm-project/commit/3168ab337635b6ed5a279cd432f95dc3da17fb2c)) I don't think think that the fix being applied here is right. It sounds like maybe DeadBlocks is out of sync?

I think by saying out of sync you're referring to the on-the-fly edge splitting mentioned in 3168ab3, which I don't think it happen in this case. The `if.else` block is pretty dead regardless of how we split the edges.


https://github.com/llvm/llvm-project/pull/88556