<Magma Talus> about global router

For common APR tools like ICC, SOCE and Talus, global router is usually invoked during placement stage and run in incremental mode until detailed router turn on. However, compared with ICC and SOCE, I found few issues of Talus global router (probably it is Talus' weakness), that Talus sometimes does not remove the deprecated segment or track when update global route (ripup or reroute), thus it leaves redundant segments there which easily cause spacing or short violation even for detailed router can not clean up at all. Especially in the case of congested area! On the other hand, global router seems not honor internal "routing blockage" of hard IP, in other words, Talus still leave few segments in routing blockage area of hard IP and does not clean it up, I do not know why?

By the way, I also find many dirty routing around pins of hard IPs, I did many experiments by using different design (it does nothing with pin shape or routing blockage surround), the same result!

I adopt the common flow: fix cell -> fix clock -> fix wire