computing lastPrintableIndex only once instead of checking in every loop
#2591
| Job | Run time |
|---|---|
| 2m 16s | |
| 1m 4s | |
| 1m 5s | |
| 1m 4s | |
| 1m 28s | |
| 1m 55s | |
| 1m 29s | |
| 10m 21s |