[PATCH] D86302: [SelectionDAG] Modify legalizing intrinsic get.active.lane.mask

[Sjoerd Meijer via Phabricator via llvm-commits]

SjoerdMeijer added inline comments.


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Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:6939
   case Intrinsic::get_active_lane_mask: {
     auto DL = getCurSDLoc();
     SDValue Index = getValue(I.getOperand(0));
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arsenm wrote:
> Why is this expanded here in the first place?
The intrinsic is used to communicate information from middle-end to back-end. The back-end transformation could reject it for different reasons. If the transformation is not triggering, the intrinsic has to be expanded to its original semantics somewhere. This place seems to be a good fit and is generic, so if there will be more use-cases than only the ARM back-end than that's covered.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86302/new/

https://reviews.llvm.org/D86302