1 files changed, 9 insertions, 5 deletions
diff --git a/src/support/bits.h b/src/support/bits.h
index f2241bea8..bd91fdec6 100644
--- a/src/support/bits.h
+++ b/src/support/bits.h
@@ -65,17 +65,21 @@ template<typename T> int CountTrailingZeroes(T v) {
 template<typename T> int CountLeadingZeroes(T v) {
   return CountLeadingZeroes(typename std::make_unsigned<T>::type(v));
 }
-template<typename T> bool IsPowerOf2(T v) { return v != 0 && PopCount(v) == 1; }
+template<typename T> bool IsPowerOf2(T v) {
+  return v != 0 && (v & (v - 1)) == 0;
+}
 
 template<typename T, typename U> inline static T RotateLeft(T val, U count) {
-  T mask = sizeof(T) * CHAR_BIT - 1;
+  auto value = typename std::make_unsigned<T>::type(val);
+  U mask = sizeof(T) * CHAR_BIT - 1;
   count &= mask;
-  return (val << count) | (val >> (-count & mask));
+  return (value << count) | (value >> (-count & mask));
 }
 template<typename T, typename U> inline static T RotateRight(T val, U count) {
-  T mask = sizeof(T) * CHAR_BIT - 1;
+  auto value = typename std::make_unsigned<T>::type(val);
+  U mask = sizeof(T) * CHAR_BIT - 1;
   count &= mask;
-  return (val >> count) | (val << (-count & mask));
+  return (value >> count) | (value << (-count & mask));
 }
 
 extern uint32_t Log2(uint32_t v);