computing lastPrintableIndex only once instead of checking in every loop
#2579
| Job | Run time |
|---|---|
| 1m 7s | |
| 1m 33s | |
| 48s | |
| 3m 11s | |
| 1m 29s | |
| 1m 22s | |
| 1m 5s | |
| 10m 35s |