[PATCH] D126201: [WIP] Very early work to enable isel of fixed length vector extracts from scalable vectors.

[David Sherwood via Phabricator via llvm-commits]

david-arm added inline comments.


================
Comment at: llvm/include/llvm/Target/TargetSelectionDAG.td:698
+// Extract/Insert fixed length subvector form scalable vector.
+def extract_subvector2 : SDNode<"ISD::EXTRACT_SUBVECTOR", SDTSubVecExtract2, []>;
+
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paulwalker-arm wrote:
> Created new variant because `SDTSubVecExtract` does not support missed datatypes.  Changing `SDTSubVecExtract` causes LLVM not to build because many isel patterns need updating.  Not 100% sure this is the way to go, just depends on how many isel patterns need to be changed.
I imagine you'll need a new ISD enum too, i.e. ISD::EXTRACT_SUBVECTOR2 because otherwise it may alias with `def extract_subvector`?


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  https://reviews.llvm.org/D126201/new/

https://reviews.llvm.org/D126201