Hi, ``` cmp = _mm_cmplt_epi8(_mm_set1_epi8(c), _mm_loadu_si128((__m128i*)n->keys)); ``` isn't it comparing them as signed bytes? I found http://www.alfredklomp.com/programming/sse-intrinsics/ with nice tips how to do unsigned compares - I hope it helps :) (or maybe I'm missing something?)