https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81389
--- Comment #3 from rockeet <rockeet at gmail dot com> --- @Martin Liška Yes, my use case is: __m128i key128 = { key }; // key is an unsigned char int idx = _mm_cmpestri(key128, 1, *(const __m128i*)(data), // don't require memory align len, _SIDD_UBYTE_OPS|_SIDD_CMP_EQUAL_ORDERED|_SIDD_LEAST_SIGNIFICANT); // ....