if(byteshift){
memmove(a->wordv, (uint8_t*)a->wordv + byteshift, a->length_W * sizeof(bigint_word_t) - byteshift);
memset((uint8_t*)&a->wordv[a->length_W] - byteshift, 0, byteshift);
if(byteshift){
memmove(a->wordv, (uint8_t*)a->wordv + byteshift, a->length_W * sizeof(bigint_word_t) - byteshift);
memset((uint8_t*)&a->wordv[a->length_W] - byteshift, 0, byteshift);