[MLIR][ArmNeon] Add a couple of negative tests for BFMMLA with scalable dimensions (llvm#145882)

Author: momchil-velikov

mlir/test/Dialect/ArmNeon/invalid.mlir

@@ -114,6 +114,16 @@ func.func @bfmmla_invalid_dimension_lhs_rhs(%acc: vector<4xf32>,
 
 // -----
 
+func.func @bfmmla_scalable_dimension_lhs_rhs(%acc: vector<4xf32>,
+                                             %lhs: vector<[8]xbf16>,
+                                             %rhs: vector<[8]xbf16>) -> vector<4xf32> {
+  // expected-error@+1 {{operand #1 must be a vector with length 8 of bfloat16 type values, but got 'vector<[8]xbf16>'}}
+  %0 = arm_neon.intr.bfmmla %acc, %lhs, %rhs : vector<[8]xbf16> to vector<4xf32>
+  return %0 : vector<4xf32>
+}
+
+// -----
+
 func.func @bfmmla_invalid_element_type_acc(%acc: vector<4xi32>,
                                            %lhs: vector<8xbf16>,
                                            %rhs: vector<8xbf16>) -> vector<4xi32> {
@@ -131,3 +141,13 @@ func.func @bfmmla_invalid_dimension_acc(%acc: vector<8xf32>,
   %0 = arm_neon.intr.bfmmla %acc, %lhs, %rhs : vector<8xbf16> to vector<8xf32>
   return %0 : vector<8xf32>
 }
+
+// -----
+
+func.func @bfmmla_scalable_dimension_acc(%acc: vector<[4]xf32>,
+                                         %lhs: vector<8xbf16>,
+                                         %rhs: vector<8xbf16>) -> vector<[4]xf32> {
+  // expected-error@+1 {{op operand #0 must be a vector with length 4 of 32-bit float values, but got 'vector<[4]xf32>'}}
+  %0 = arm_neon.intr.bfmmla %acc, %lhs, %rhs : vector<8xbf16> to vector<[4]xf32>
+  return %0 : vector<[4]xf32>
+}