computing lastPrintableIndex only once instead of checking in every loop
#2627
| Job | Run time |
|---|---|
| 1m 1s | |
| 2m 18s | |
| 1m 5s | |
| 58s | |
| 1m 15s | |
| 1m 19s | |
| 1m 25s | |
| 9m 21s |