[PATCH] D38128: Handle COPYs of physregs better (regalloc hints)

[Ulrich Weigand via Phabricator via llvm-commits]

uweigand added a comment.

In https://reviews.llvm.org/D38128#904899, @jonpa wrote:

> Would any of these be an improvement worth trying, then?
>
> (1) If the source phys-reg is contained in the regclass of an immediately following instruction using the vreg, then increase the priority of the hint of that phys-reg.
>  (2) A simpler alternative would be to simply prefer phys-reg sources more than phys-reg dest-regs (if weight is equal). That would catch all the cases of (1).


I believe (2) makes sense ...  certainly worth a try.


https://reviews.llvm.org/D38128