[Mlir-commits] [mlir] [mlir][VectorOps] Add vector.interleave operation (1/4) (PR #80965)

[Benjamin Maxwell]

================
@@ -478,6 +478,69 @@ def Vector_ShuffleOp :
   let hasCanonicalizer = 1;
 }
 
+def Vector_InterleaveOp :
+  Vector_Op<"interleave", [Pure,
+    AllTypesMatch<["lhs", "rhs"]>,
+    TypesMatchWith<
+    "type of 'result' is double the width of the inputs",
+    "lhs", "result",
+    [{
+      [&]() -> ::mlir::VectorType {
+        auto vectorType = ::llvm::cast<mlir::VectorType>($_self);
+        ::mlir::VectorType::Builder builder(vectorType);
+        if (vectorType.getRank() == 0) {
+          static constexpr int64_t v2xty_shape[] = { 2 };
+          return builder.setShape(v2xty_shape);
+        }
+        auto lastDim = vectorType.getRank() - 1;
+        return builder.setDim(lastDim, vectorType.getDimSize(lastDim) * 2);
+      }()
+    }]>]> {
+  let summary = "constructs a vector by interleaving two input vectors";
+  let description = [{
+    The interleave operation constructs a new vector by interleaving the
+    elements from the trailing (or final) dimension of two input vectors,
+    returning a new vector where the trailing dimension is twice the size.
+
+    Note that for the n-D case this differs from the interleaving possible with
----------------
MacDue wrote:

So, in short:

1. There's basically no support for `shufflevector`, `vector.shuffle`, etc for scalable vectors 
2. I believe so 

For `2`., while you can hack it and claim to arbitrary pattern means interleave for scalable vectors, there's no pattern that'd actually make sense with the current semantics of `vector.shuffle`. So I think that's just adding tricky edge cases in the meaning of the op. 


https://github.com/llvm/llvm-project/pull/80965