diff --git a/clang/lib/Support/RISCVVIntrinsicUtils.cpp b/clang/lib/Support/RISCVVIntrinsicUtils.cpp
--- a/clang/lib/Support/RISCVVIntrinsicUtils.cpp
+++ b/clang/lib/Support/RISCVVIntrinsicUtils.cpp
@@ -13,6 +13,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include <numeric>
 #include <optional>
@@ -992,16 +993,18 @@
                    Policy::PolicyType::Undisturbed), // TUMU
             Policy(Policy::PolicyType::Agnostic,
                    Policy::PolicyType::Undisturbed)}; // TAMU
-
-  if (HasTailPolicy)
+  if (HasTailPolicy && !HasMaskPolicy)
     return {Policy(Policy::PolicyType::Undisturbed,
                    Policy::PolicyType::Agnostic, true), // TUM
             Policy(Policy::PolicyType::Agnostic, Policy::PolicyType::Agnostic,
                    true)}; // TAM
-
-  return {
-      Policy(Policy::PolicyType::Omit, Policy::PolicyType::Agnostic),     // MA
-      Policy(Policy::PolicyType::Omit, Policy::PolicyType::Undisturbed)}; // MU
+  if (!HasTailPolicy && HasMaskPolicy)
+    return {
+        Policy(Policy::PolicyType::Omit, Policy::PolicyType::Agnostic), // MA
+        Policy(Policy::PolicyType::Omit,
+               Policy::PolicyType::Undisturbed)}; // MU
+  llvm_unreachable("An RVV instruction should not be without both tail policy "
+                   "and mask policy");
 }
 
 void RVVIntrinsic::updateNamesAndPolicy(bool IsMasked, bool HasPolicy,