diff --git a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
--- a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
+++ b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
@@ -695,9 +695,8 @@
     return cmpResult == APFloat::cmpUnordered;
   case CmpFPredicate::AlwaysTrue:
     return true;
-  default:
-    llvm_unreachable("unknown comparison predicate");
   }
+  llvm_unreachable("unknown comparison predicate");
 }
 
 // Constant folding hook for comparisons.