AR# 15611

描述

What do the checksum numbers printed by the placer and router algorithms mean?

解决方案

Beginning with the version 5.1i software, placer scores are no longer printed, as users were reading too much significance into the scores. The scoring algorithm had a tendency to vary abruptly as different placer algorithms were applied, which caused unnecessary alarm. 

Without the placement score, however, it is difficult to tell if two different PAR runs are producing identical results, something that is critical when an attempt to reproduce software problems is made. The checksum number was introduced to provide an indication of whether two PAR runs are tracking each other exactly. 

For example: 

Phase 1.1 (Checksum:9896af) REAL time: 9 secs