Add a TypeIsPred.

Mostly one would use the type specification directly on the operand, but for
cases where the type of the operand depends on other operand types, `TypeIs`
attribute can be used to construct verification methods.

PiperOrigin-RevId: 258411758

mlir/include/mlir/IR/OpBase.td

@@ -1170,6 +1170,13 @@ class TCopVTEtIs<int idx, Type type> : And<[
    SubstLeaves<"$_self", "getElementTypeOrSelf($_op.getOperand(" # idx # "))",
      type.predicate>]>;
 
+// Predicate to verify that a named argument or result's element type matches a
+// given type.
+class TypeIsPred<string name, Type type> :
+   SubstLeaves<"$_self", "$" # name # ".getType()", type.predicate>;
+class TypeIs<string name, Type type> : PredOpTrait<
+  "'" # name # "' is " # type.description, TypeIsPred<name, type>>;
+
 // Predicate to verify that a named argument or result's element type matches a
 // given type.
 class ElementTypeIsPred<string name, Type type> : And<[

mlir/test/lib/TestDialect/TestOps.td

@@ -187,6 +187,15 @@ def OperandOneAndResultHaveSameType :
   let results = (outs AnyTensor:$res);
 }
 
+def IfFirstOperandIsNoneThenSoIsSecond :
+    TEST_Op<"if_first_operand_is_none_then_so_is_second", [PredOpTrait<
+    "has either both none type operands or first is not none",
+     Or<[
+        And<[TypeIsPred<"x", NoneType>, TypeIsPred<"y", NoneType>]>,
+        Neg<TypeIsPred<"x", NoneType>>]>>]> {
+  let arguments = (ins AnyType:$x, AnyType:$y);
+}
+
 //===----------------------------------------------------------------------===//
 // Test Patterns
 //===----------------------------------------------------------------------===//

mlir/test/mlir-tblgen/types.mlir

@@ -174,3 +174,11 @@ func @same_types_shape_mismatch(%arg0: tensor<1x2xi32>, %arg1: tensor<2x1xi32>)
   %0 = "test.operand_one_and_result_have_same_type"(%arg0, %arg1) : (tensor<1x2xi32>, tensor<2x1xi32>) -> tensor<2x1xi32>
   return
 }
+
+// -----
+
+func @does_not_have_i32(%arg0: tensor<1x2xi32>, %arg1: none) {
+  // expected-error@+1 {{either both none type operands or first is not none}}
+  "test.if_first_operand_is_none_then_so_is_second"(%arg1, %arg0) : (none, tensor<1x2xi32>) -> ()
+  return
+}