How to accelerate ncelab phase when invoking irun?

Hi,

Below is part of the irun log file which summarizes the time costs for each phase while compiling my ENV. Obviously, most of the time is consumed in ncelab phase, is there any way to optimize the efficiency on ncelab?

TOOL: irun(64) 15.20-s024: Started on Nov 15, 2017 at 15:11:41 CST
Running makelib                               on: Nov 15, 2017 at 15:11:41
Running ncvlog                                 on: Nov 15, 2017 at 15:11:43
Running ncsc_run                             on: Nov 15, 2017 at 15:11:48
Running ncelab                                 on: Nov 15, 2017 at 15:11:50
TOOL: irun(64) 15.20-s024: Exiting  on Nov 15, 2017 at 15:12:47 CST (total: 00:01:06)

Thanks.