diff --git a/mlir/include/mlir/Dialect/Math/IR/MathOps.td b/mlir/include/mlir/Dialect/Math/IR/MathOps.td
--- a/mlir/include/mlir/Dialect/Math/IR/MathOps.td
+++ b/mlir/include/mlir/Dialect/Math/IR/MathOps.td
@@ -667,7 +667,10 @@
 
     The `round` operation returns the operand rounded to the nearest integer
     value in floating-point format. It takes one operand of floating point type
-    (i.e., scalar, tensor or vector) and produces one result of the same type.
+    (i.e., scalar, tensor or vector) and produces one result of the same type.  The
+    operation rounds the argument to the nearest integer value in floating-point
+    format, rounding halfway cases away from zero, regardless of the current
+    rounding direction.
 
     Example: