[llvm] [NVPTX] Fuse abs into min/max/redux (PR #220445)

[Artem Belevich via llvm-commits]

https://github.com/Artem-B commented:

Patch description could use more details on what exactly the patch is doing, and why it's useful.

Overall looks OK.

https://github.com/llvm/llvm-project/pull/220445