[PATCH] D11569: [AArch64] Favor extended reg patterns for sub

[Geoff Berry]

gberry added a comment.

In http://reviews.llvm.org/D11569#215962, @rengolin wrote:

> Is this avoiding a shift plus extend sub, for a shift-extend sub?
>
> If so, would be good to add a CHECK-NOT for the extra instructions that you don't want to see.


I don't think this would add much to the test since we're already checking for the shift-extend subs.  Adding CHECK-NOTs for extra extends or shifts would just be checking that we're not generating redundant code, which doesn't seem to be of much value.  Do you agree?


http://reviews.llvm.org/D11569