# include <nmmintrin.h> // Intel header for _mm_popcnt_u64() intrinsic
#endif
+#if defined(USE_PEXT)
+# include <immintrin.h> // Header for _pext_u64() intrinsic
+#else
+# define _pext_u64(b, m) (0)
+#endif
+
# if !defined(NO_PREFETCH) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
# include <xmmintrin.h> // Intel and Microsoft header for _mm_prefetch()
# endif