[PATCH] D127710: [SelectionDAG] Enable WidenVecOp_VECREDUCE_SEQ for scalable vector

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen added inline comments.


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Comment at: llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp:6153
+    unsigned GCD = greatestCommonDivisor(OrigElts, WideElts);
+    EVT SplatVT = EVT::getVectorVT(*DAG.getContext(), ElemVT,
+                                   ElementCount::getScalable(GCD));
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Jimerlife wrote:
> sdesmalen wrote:
> > For SVE there is still the problem that the type action of SplatVT may be `TypeWiden` as well, because we haven't implemented all support for nxv1 types yet. The approach taken here seems valid though, it just means that we can't have the same tests for SVE yet.
> Should I need to add `getTypeAction(SplatVT) != TargetLowering::TypeWidenVector` to avoid this problem now?
No I don't think that's necessary, but thanks for the suggestion! When we fix the nxv1 legalisation of insert_subvector, we'll get the support added in this patch for free. And the compiler will currently crash with an error either way :) It was more just an observation.


Repository:
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  https://reviews.llvm.org/D127710/new/

https://reviews.llvm.org/D127710