[PATCH] D52221: require lower-switch in preISel passes for AMDGPU

[Sameer Sahasrabuddhe via Phabricator via llvm-commits]

sameerds added a comment.

In https://reviews.llvm.org/D52221#1238116, @nhaehnle wrote:

> Good to hear the new DA can handle this. We need lowered switches for the control flow lowering anyway, though, so we may as well do it this way.
>
> The test case is extremely mysterious to me, though. What is it that's actually being tested here? From the description I understand it's the divergence of the phi in sw.epilog? I don't see how that relates to the CHECK lines.


Updated the test to better convey the intention. Does that help? Note that since this change is a backend-specific workaround, the test focuses on the symptom seen in the results of si-annotate-control-flow rather than checking the results of divergence analysis.


Repository:
  rL LLVM

https://reviews.llvm.org/D52221