response to suggestions

Signed-off-by: Alexandre Eichenberger <[email protected]>

Author: AlexandreEichenberger

mlir/include/mlir/Dialect/MemRef/IR/MemRefOps.td

@@ -1351,9 +1351,12 @@ def MemRef_PrefetchOp : MemRef_Op<"prefetch"> {
     instruction cache.
   }];
 
-  // The memref argument is labeled with a MemWrite side effect to enforce a
+  // The memref argument is labeled with a side effect to enforce a
   // relative ordering of the prefetch and other memory operations targeting
   // that memory stream.
+  // We need it to be a write otherwise the operation would be trivially removed
+  // since it does not produce a value.
+
   let arguments = (ins Arg<AnyMemRef, "prefetch address", [MemWrite]> :$memref,
                        Variadic<Index>:$indices,
                        BoolAttr:$isWrite,