[Lldb-commits] [PATCH] D155269: [lldb][AArch64] Add SME streaming vector length pseudo register

Mon Jul 17 01:01:51 PDT 2023

DavidSpickett planned changes to this revision.
DavidSpickett added a comment.

> As you say above, we can show svg when in non-streaming mode but we can't show vg when in streaming mode. Should we only show a single vg for the currently-available registers?

I will admit I don't have practical experience to justify adding svg, I'm just guessing it would be nice to know what vector length you're about to switch into. That argument plays just as well for streaming -> non-streaming switches though.

The problem with that is we don't have an obvious name (or place) to show the non-streaming vg. For `svg`, we're adding the new register set to hold `svcr` anyway (which is essential because it's the only way to know the active mode). The architecture doesn't assign a new name to the non-streaming mode, so you could call it "svevg" and "ssvevg" but that's no help to the average person who hasn't (and shouldn't have to) read the manual.

Given that this isn't an essential feature, I'll put this on the backburner. At least until after 17, once I have more experience writing SME code.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D155269/new/

https://reviews.llvm.org/D155269