[PATCH] D140693: [Driver][RISCV] Adjust the priority between -mcpu, -mtune and -march

[Kito Cheng via Phabricator via cfe-commits]

kito-cheng added a comment.

> So if I read this correctly, the effect of this is that we never pass -target-cpu to the backend after this patch and will only pass -target-feature and -tune-cpu?

Yes, that's prevent us taking any extensions from `-target-cpu`, so always pass `-target-feature` and `-tune-cpu` only.

> The code in riscv::getRISCVArch prioritizes -march over -mcpu for architecture extensions for setting -target-features.
>
> But the backend still applies extensions from -target-cpu via the tablegen features from RISCV.td.
>
> So its not even a "priority", we end up with a union.

Damm, you are right, that...even worth than I thought before, let me update the summary.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140693/new/

https://reviews.llvm.org/D140693