diff --git a/mlir/lib/Parser/TypeParser.cpp b/mlir/lib/Parser/TypeParser.cpp
--- a/mlir/lib/Parser/TypeParser.cpp
+++ b/mlir/lib/Parser/TypeParser.cpp
@@ -34,6 +34,8 @@
   case Token::kw_f16:
   case Token::kw_f32:
   case Token::kw_f64:
+  case Token::kw_f80:
+  case Token::kw_f128:
   case Token::kw_index:
   case Token::kw_none:
   case Token::exclamation_identifier:
diff --git a/mlir/test/IR/parser.mlir b/mlir/test/IR/parser.mlir
--- a/mlir/test/IR/parser.mlir
+++ b/mlir/test/IR/parser.mlir
@@ -1420,3 +1420,7 @@
 // be handled by the dialect.
 // CHECK: test.dialect_custom_format_fallback custom_format_fallback
 test.dialect_custom_format_fallback custom_format_fallback
+
+// Check that an op with an optional result parses f80 as type.
+// CHECK: test.format_optional_result_d_op : f80
+test.format_optional_result_d_op : f80
diff --git a/mlir/test/lib/Dialect/Test/TestOps.td b/mlir/test/lib/Dialect/Test/TestOps.td
--- a/mlir/test/lib/Dialect/Test/TestOps.td
+++ b/mlir/test/lib/Dialect/Test/TestOps.td
@@ -1962,6 +1962,12 @@
   (`:` functional-type($optional, $variadic)^)? attr-dict
 }]>;
 
+def FormatOptionalResultDOp
+  : TEST_Op<"format_optional_result_d_op" > {
+  let results = (outs Optional<F80>:$optional);
+  let assemblyFormat = "(`:` type($optional)^)? attr-dict";
+}
+
 def FormatTwoVariadicOperandsNoBuildableTypeOp
     : TEST_Op<"format_two_variadic_operands_no_buildable_type_op",
               [AttrSizedOperandSegments]> {