diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -124,7 +124,7 @@
 
   let arguments = (ins Variadic<AnyType>:$varList);
 
-  let assemblyFormat = "attr-dict ($varList^ `:` type($varList))?";
+  let assemblyFormat = [{ ( `(` $varList^ `:` type($varList) `)` )? attr-dict}];
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/mlir/test/Dialect/OpenMP/ops.mlir b/mlir/test/Dialect/OpenMP/ops.mlir
--- a/mlir/test/Dialect/OpenMP/ops.mlir
+++ b/mlir/test/Dialect/OpenMP/ops.mlir
@@ -29,19 +29,19 @@
 }
 
 // CHECK-LABEL: func @omp_flush
-// CHECK-SAME: %[[ARG0:.*]]: !llvm.i32
+// CHECK-SAME: ([[ARG0:%.*]]: !llvm.i32) {
 func @omp_flush(%arg0 : !llvm.i32) -> () {
   // Test without data var
   // CHECK: omp.flush
   omp.flush
 
   // Test with one data var
-  // CHECK: omp.flush %[[ARG0]] : !llvm.i32
-  "omp.flush"(%arg0) : (!llvm.i32) -> ()
+  // CHECK: omp.flush([[ARG0]] : !llvm.i32)
+  omp.flush(%arg0 : !llvm.i32)
 
   // Test with two data var
-  // CHECK: omp.flush %[[ARG0]], %[[ARG0]] : !llvm.i32, !llvm.i32
-  "omp.flush"(%arg0, %arg0): (!llvm.i32, !llvm.i32) -> ()
+  // CHECK: omp.flush([[ARG0]], [[ARG0]] : !llvm.i32, !llvm.i32)
+  omp.flush(%arg0, %arg0: !llvm.i32, !llvm.i32)
 
   return
 }
diff --git a/mlir/test/Target/openmp-llvm.mlir b/mlir/test/Target/openmp-llvm.mlir
--- a/mlir/test/Target/openmp-llvm.mlir
+++ b/mlir/test/Target/openmp-llvm.mlir
@@ -24,10 +24,18 @@
   omp.flush
 
   // CHECK: call void @__kmpc_flush(%struct.ident_t* @{{[0-9]+}}
-  omp.flush %arg0 : !llvm.i32
+  omp.flush (%arg0 : !llvm.i32)
 
   // CHECK: call void @__kmpc_flush(%struct.ident_t* @{{[0-9]+}}
-  omp.flush %arg0, %arg0 : !llvm.i32, !llvm.i32
+  omp.flush (%arg0, %arg0 : !llvm.i32, !llvm.i32)
+
+  %0 = llvm.mlir.constant(1 : i64) : !llvm.i64
+  //  CHECK: alloca {{.*}} align 4
+  %1 = llvm.alloca %0 x !llvm.i32 {in_type = i32, name = "a"} : (!llvm.i64) -> !llvm.ptr<i32>
+  // CHECK: call void @__kmpc_flush(%struct.ident_t* @{{[0-9]+}}
+  omp.flush
+  //  CHECK: load i32, i32*
+  %2 = llvm.load %1 : !llvm.ptr<i32>
 
   // CHECK-NEXT:    ret void
   llvm.return