[PATCH] D106237: [ISel] Port AArch64 HADD and RHADD to ISel

[Dave Green via Phabricator via llvm-commits]

dmgreen added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp:987-988
+    NVT = VT.changeVectorElementType(NVT);
+  if (!TLI.isOperationLegalOrCustom(AVGOpc, NVT))
+    return SDValue();
+
----------------
lebedev.ri wrote:
> Can we get to here where the operations aren't legal yet?
Yes I think so (IIUYC). It'll be run as part of any of the DAG combines. There is very little legalization for AVG at the moment, so I'm not sure we can create a lot of illegal nodes.

(But I'm not an expert of when it's best to create illegal target-independent nodes and when not)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D106237/new/

https://reviews.llvm.org/D106237