diff --git a/libcxx/include/__bit/countl.h b/libcxx/include/__bit/countl.h
--- a/libcxx/include/__bit/countl.h
+++ b/libcxx/include/__bit/countl.h
@@ -74,7 +74,7 @@
         int __iter = 0;
         const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
         while (true) {
-            __t = std::__rotr(__t, __ulldigits);
+            __t = std::__rotl(__t, __ulldigits);
             if ((__iter = std::__countl_zero(static_cast<unsigned long long>(__t))) != __ulldigits)
                 break;
             __ret += __iter;
diff --git a/libcxx/include/__bit/rotate.h b/libcxx/include/__bit/rotate.h
--- a/libcxx/include/__bit/rotate.h
+++ b/libcxx/include/__bit/rotate.h
@@ -35,11 +35,16 @@
   return (__t >> (__cnt % __dig)) | (__t << (__dig - (__cnt % __dig)));
 }
 
+template <class _Tp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp __rotl(_Tp __t, int __cnt) _NOEXCEPT {
+  return std::__rotr(__t, -__cnt);
+}
+
 #if _LIBCPP_STD_VER >= 20
 
 template <__libcpp_unsigned_integer _Tp>
 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp rotl(_Tp __t, int __cnt) noexcept {
-  return std::__rotr(__t, -__cnt);
+  return std::__rotl(__t, __cnt);
 }
 
 template <__libcpp_unsigned_integer _Tp>