Function isqrt

src/hacklib.c:681–700

integer square root function without using floating point */

/* integer square root function without using floating point */
int
isqrt(int val)
{
    int rt = 0;
    int odd = 1;
    /*
     * This could be replaced by a faster algorithm, but has not been because:
     * + the simple algorithm is easy to read;
     * + this algorithm does not require 64-bit support;
     * + in current usage, the values passed to isqrt() are not really that
     *   large, so the performance difference is negligible;
     * + isqrt() is used in only few places, which are not bottle-necks.
     */
    while (val >= odd) {
        val = val - odd;
        odd = odd + 2;
        rt = rt + 1;
    }
    return rt;
}

/* are two points lined up (on a straight line)? */
boolean