diff --git a/mlir/include/mlir/ExecutionEngine/CRunnerUtils.h b/mlir/include/mlir/ExecutionEngine/CRunnerUtils.h
--- a/mlir/include/mlir/ExecutionEngine/CRunnerUtils.h
+++ b/mlir/include/mlir/ExecutionEngine/CRunnerUtils.h
@@ -45,9 +45,7 @@
 constexpr bool isPowerOf2(int N) { return (!(N & (N - 1))); }
 
 constexpr unsigned nextPowerOf2(int N) {
-  if (N <= 1)
-    return 1;
-  return isPowerOf2(N) ? N : 2 * nextPowerOf2((N + 1) / 2);
+  return (N <= 1) ? 1 : (isPowerOf2(N) ? N : 2 * nextPowerOf2((N + 1) / 2));
 }
 
 template <typename T, int Dim, bool IsPowerOf2>
@@ -59,8 +57,8 @@
     static_assert(detail::nextPowerOf2(sizeof(T[Dim])) == sizeof(T[Dim]),
                   "size error");
   }
-  constexpr T &operator[](unsigned i) { return vector[i]; }
-  constexpr const T &operator[](unsigned i) const { return vector[i]; }
+  inline T &operator[](unsigned i) { return vector[i]; }
+  inline const T &operator[](unsigned i) const { return vector[i]; }
 
 private:
   T vector[Dim];
@@ -76,8 +74,8 @@
     static_assert(detail::nextPowerOf2(sizeof(T[Dim])) < 2 * sizeof(T[Dim]),
                   "size error");
   }
-  constexpr T &operator[](unsigned i) { return vector[i]; }
-  constexpr const T &operator[](unsigned i) const { return vector[i]; }
+  inline T &operator[](unsigned i) { return vector[i]; }
+  inline const T &operator[](unsigned i) const { return vector[i]; }
 
 private:
   T vector[Dim];
@@ -88,8 +86,8 @@
 // N-D vectors recurse down to 1-D.
 template <typename T, int Dim, int... Dims>
 struct Vector {
-  constexpr Vector<T, Dims...> &operator[](unsigned i) { return vector[i]; }
-  constexpr const Vector<T, Dims...> &operator[](unsigned i) const {
+  inline Vector<T, Dims...> &operator[](unsigned i) { return vector[i]; }
+  inline const Vector<T, Dims...> &operator[](unsigned i) const {
     return vector[i];
   }