iterate bits in 128-bit value

size_t offset = 8;
while(offset--){ 
    uint16_t word = _mm_movemask_epi8((__m128i) value); 
    for(int8_t index = offset; index < 128; index += 8){
        if(word & 1){ 
            // index was set
        }   
        word >>= 1;
    }
    value <<= 1; 
}