[mlir][ArmSME] Fix scalable dims check in isValidSMETileVectorType (#65254)

Check for allDimsScalable is incorrect and currently permits fixed
vectors.

Author: c-rhodes

mlir/lib/Dialect/ArmSME/Utils/Utils.cpp

@@ -31,7 +31,7 @@ bool mlir::arm_sme::isValidSMETileElementType(Type type) {
 }
 
 bool mlir::arm_sme::isValidSMETileVectorType(VectorType vType) {
-  if ((vType.getRank() != 2) && vType.allDimsScalable())
+  if ((vType.getRank() != 2) || !vType.allDimsScalable())
     return false;
 
   auto elemType = vType.getElementType();

mlir/test/Dialect/ArmSME/vector-ops-to-sme.mlir

@@ -154,6 +154,17 @@ func.func @transfer_write_2d_zero__non_memref_type(%arg0 : tensor<?x?xi8>) -> te
   return %0 : tensor<?x?xi8>
 }
 
+// -----
+
+// CHECK-LABEL: @transfer_write_2d__fixed
+// CHECK: vector.transfer_write
+// CHECK-NOT: arm_sme.tile_store
+func.func @transfer_write_2d__fixed(%vector : vector<16x16xi8>, %dest : memref<?x?xi8>) {
+  %c0 = arith.constant 0 : index
+  vector.transfer_write %vector, %dest[%c0, %c0] {in_bounds = [true, true]} : vector<16x16xi8>, memref<?x?xi8>
+  return
+}
+
 // =============================================================================
 // vector.broadcast
 // =============================================================================