Reduce running time for report

[oharboe]

Description

1. untar https://drive.google.com/file/d/1OhTilBdF_m8QiEw4ujTOXB-seuToESH_/view?usp=sharing
2. ./run-me-ChipTop-asap7-flat.sh, which runs report_metrics 5 "global route

Takes a long time, longer than global routing.

Suggested Solution

Speed up the above

Additional Context

This is from MegaBoom.

[maliberty]

@gadfort I'm guessing this will be related to the psm work you are planning to do.

[gadfort]

@maliberty I don't think so. Looking at the report_metrics in ORFS there is no call to psm. Only calls to STA. Might be helpful if @oharboe is able to narrow down the offending calls inside that function.

[maliberty]

I was thinking reporting meant the final report step that includes psm. Narrowing would be helpful.

[oharboe]

I was thinking reporting meant the final report step that includes psm. Narrowing would be helpful.

Yes: all the time is spent in OpenSTA, so changing how OpenSTA is used or changing OpenSTA itself that could move the needle.

The test case is quick to run: fire it up in the debugger suspend/resume and you'll see after a few seconds and minutes where time is spent.

Some of this may be fixable by modifying Metrics.tcl; a single pass over the data to collect all information instead of many passes to collect pieces of information:

https://github.com/The-OpenROAD-Project/OpenROAD/blob/fcd96313df26a42bfd967a10b42c7baaa4033a07/src/Metrics.tcl#L128

[maliberty]

I expect most of the time will be in recomputing the timing & power not metric collection.