+ /*
+ * Even if we know the target is much closer to 'hi'
+ * than 'lo', if we pick too precisely and overshoot
+ * (e.g. when we know 'mi' is closer to 'hi' than to
+ * 'lo', pick 'mi' that is higher than the target), we
+ * end up narrowing the search space by a smaller
+ * amount (i.e. the distance between 'mi' and 'hi')
+ * than what we would have (i.e. about half of 'lo'
+ * and 'hi'). Hedge our bets to pick 'mi' less
+ * aggressively, i.e. make 'mi' a bit closer to the
+ * middle than we would otherwise pick.
+ */
+ kyv = (kyv * 6 + lov + hiv) / 8;
+ if (lov < hiv - 1) {
+ if (kyv == lov)
+ kyv++;
+ else if (kyv == hiv)
+ kyv--;
+ }