[Mlir-commits] [mlir] [mlir][Vector] Add `vector.to_elements` op (PR #141457)

[James Newling]

================
@@ -789,6 +789,57 @@ def Vector_FMAOp :
   }];
 }
 
+def Vector_ToElementsOp : Vector_Op<"to_elements", [
+    Pure,
+    TypesMatchWith<"operand element type matches result types",
+                   "input", "elements", "SmallVector<Type>("
+                   "::llvm::cast<VectorType>($_self).getNumElements(), "
+                   "::llvm::cast<VectorType>($_self).getElementType())">]> {
+  let summary = "operation that decomposes a vector into all its scalar elements";
+  let description = [{
+    This operation decomposes all the scalar elements from a vector. The
+    decomposed scalar elements are returned in row-major order. The number of
+    scalar results must match the number of elements in the input vector type.
+    All the result elements have the same result type, which must match the
+    element type of the input vector. Scalable vectors are not supported.
+
+    Examples:
+
+    ```mlir
+    // Decompose a 0-D vector.
+    %0 = vector.to_elements %v0 : vector<f32>
+    // %0 = %v0[0]
+
+    // Decompose a 1-D vector.
+    %0:2 = vector.to_elements %v1 : vector<2xf32>
+    // %0#0 = %v1[0]
+    // %0#1 = %v1[1]
+
+    // Decompose a 2-D.
+    %0:6 = vector.to_elements %v2 : vector<2x3xf32>
+    // %0#0 = %v2[0, 0]
+    // %0#1 = %v2[0, 1]
+    // %0#2 = %v2[0, 2]
+    // %0#3 = %v2[1, 0]
+    // %0#4 = %v2[1, 1]
+    // %0#5 = %v2[1, 2]
+
+    // Decompose a 3-D vector.
+    %0:6 = vector.to_elements %v3 : vector<3x1x2xf32>
+    // %0#0 = %v3[0, 0, 0]
+    // %0#1 = %v3[0, 0, 1]
+    // %0#2 = %v3[1, 0, 0]
+    // %0#3 = %v3[1, 0, 1]
+    // %0#4 = %v3[2, 0, 0]
+    // %0#5 = %v3[2, 0, 1]
+    ```
+  }];
+
+  let arguments = (ins AnyVectorOfAnyRank:$input);
----------------
newling wrote:

```suggestion
  let arguments = (ins AnyFixedVectorOfAnyRank:$input);
```
perhaps?

https://github.com/llvm/llvm-project/pull/141457