s_mp_alloc
void *s_mp_alloc(size_t nb, size_t ni, int flag); /* general allocator */
if((DIGITS(mp) = s_mp_alloc(prec, sizeof(mp_digit), kmflag)) == NULL)
if((DIGITS(mp) = s_mp_alloc(ALLOC(from), sizeof(mp_digit), FLAG(from))) == NULL)
if((tmp = s_mp_alloc(ALLOC(from), sizeof(mp_digit), FLAG(from))) == NULL)
if((tmp = s_mp_alloc(min, sizeof(mp_digit), FLAG(mp))) == NULL)