[PATCH] D126439: [LegalizeTypes][VP] Add widen and split support for vp.fptrunc and vp.fpext

Wed Jun 1 00:10:49 PDT 2022

frasercrmck accepted this revision.
frasercrmck added a comment.
This revision is now accepted and ready to land.

LGTM. As pointed out I think `WidenVecRes_Convert` needs some extra attention to cover the missing cases for VP nodes, but we're already using it for `VP_TRUNCATE` so that could be done as a follow-up.

================
Comment at: llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp:3781
   case ISD::ANY_EXTEND:
+  case ISD::VP_FP_EXTEND:
   case ISD::FP_EXTEND:
----------------
This is really nitpicky but why is VP_FP_EXTEND before FP_EXTEND but VP_FP_FOUND is after FP_FOUND?

================
Comment at: llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp:3793
   case ISD::ZERO_EXTEND:
     Res = WidenVecRes_Convert(N);
     break;
----------------
Looking at `WidenVecRes_Convert` it seems like it's possible VP operations to silently fall through some cracks we haven't covered. Should we add a few asserts to the cases we haven't handled? I'm thinking the scalar unroll code, which would silently drop the mask/evl (I think) and the case above it.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126439/new/

https://reviews.llvm.org/D126439