[PATCH] D27293: [WIP] Cleanup SplitCSR implementation

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added a comment.

In https://reviews.llvm.org/D27293#610230, @MatzeB wrote:

> I think `getMinimalPhysRegClass()` may be more restrictive than necessary (I imagine you can end up the class for A B C D as the smallest class on X86 while the full GPR class would be more suitable on X86). I don't think we have a better generic notion today, so all that is left is to enumerate register classes that allow suitable spilling and cheaply copying between the registers inside the class.


That said I think I would be fine to use getMinimalPhysRegClass() for the cases not covered by the explicit enumeration.


https://reviews.llvm.org/D27293