integer sqrt

sqrt_int32.c

/* Simple SQRT calculation
 * NOTE: result fits within uint16_t (of course)
 */
uint32_t sqrt_int32(uint32_t x)
{
    uint32_t res = 0;
    uint32_t add = 0x8000;
    uint32_t temp;
    uint8_t  i;

    for(i=0; i<16; i++) {
        temp = res | add;
        if (x>= (temp*temp)) {
            res = temp;
        }
        add>>=1;
    }
    return res;
}