[PATCH] D100085: [X86] Support -march=rocketlake

Thu Apr 8 10:20:25 PDT 2021

craig.topper added inline comments.

================
Comment at: llvm/lib/Target/X86/X86.td:767
+  // Rocketlake
+  list<SubtargetFeature> RKLAdditionalFeatures = [FeatureAES,
+                                                  FeatureXSAVEC,
----------------
FreddyYe wrote:
> craig.topper wrote:
> > Is this list this long because SKL includes SGX but RKL doesn't?
> Yes. And I don't know any simple ways to exclude SGX here, any suggestions?
Nothing pretty. Guess it depends on if SGX is going to not appear in more future CPUs or if this is a one off case. If it's going to continue then we could remove it from the inheritance and just give it to SKL, ICL, CNL, etc. individually.

Or we could just not default SGX on for any CPU. It's probably not all that useful in the backend anyway. Clang will put it in the target-feature attribute anyway. Having it in the backend feature lists doesn't really do anything since I don't think we have any IR intrinsics for SGX.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D100085/new/

https://reviews.llvm.org/D100085