[Mlir-commits] [mlir] [MLIR][ArmSVE] Add initial lowering of vector.contract to SVE `*MMLA` instructions (PR #135636)

[Andrzej Warzyński]

================
@@ -56,6 +56,9 @@ class LowerContractionToSMMLAPattern
     // Avoid 0-D vectors and 1-D rhs:
     if (!lhsType.hasRank() || !rhsType.hasRank() || rhsType.getRank() < 2)
       return failure();
+    // Avoid scalable vectors.
----------------
banach-space wrote:

Let me rephrase.

The comment “Avoid scalable vectors.” explains **what** the code is doing, which is already clear from the code itself. What would be more helpful here is a brief note on **why** scalable vectors are being avoided. This may be obvious to those familiar with NEON and SVE, but adding a bit of context would make the intent clearer for others as well.

Relatedly, it might be worth mentioning that there's a separate implementation for NEON and SVE. Even within Arm, not everyone is aware that I8MM is available for both.

All I am asking for is a small addition to the comment.

https://github.com/llvm/llvm-project/pull/135636