[PATCH] D102766: [SelectionDAG] Implement PromoteIntRes_INSERT_SUBVECTOR

[Peter Waller via Phabricator via llvm-commits]

peterwaller-arm added inline comments.


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Comment at: llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp:4743
+  SDValue SubVecPtr =
+      TLI.getVectorElementPointer(DAG, StackPtr, VecVT, ScaledIdx, Clamp);
+  Store = DAG.getStore(Store, dl, SubVec, SubVecPtr, PtrInfo, SmallestAlign);
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My thinking here is that the clamping logic of getVectorElementPointer isn't appropriate for what is needed here. It's necessary to ensure the upper element of the inserted fixed-width vector fits into the scalable vector. getVectorElementPointer is effectively only forcing that the first element is in bounds, but it's the last element which matters.



Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D102766/new/

https://reviews.llvm.org/D102766