The-OpenROAD-Project / The-OpenROAD-Project/OpenROAD

GPL: Strange behavior when enabling repair_timing during timing-driven

Open
#10,751 6 comments 0 reactions 1 assignee View on GitHub

Nobody has claimed this yet.

gpl rsz Stale
Dominant language
Verilog
Stars
3.1k
Forks
1k
Avg merge
2d 23h
Merged PRs (30d)
136

Description

In this example, the worst endpoint slack is -0.028 ns after running repair_timing.
Just after that, the measured WNS is -0.270 ns. And after the final GPL steps, the measured WNS is -0.110 ns.
Something seems wrong here. I don't know if we are incorrectly estimating timing here.

If the -0.028 slack is correct, then we are just degrading the placement in the final steps.

Image

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.