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

POLYGON statements dropped from LEF

Open
#10,256 9 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

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

Description

Describe the bug

It seems that POLYGON statements in LEF files are currently dropped.

This is an example from sky130_ef_io, more specifically sky130_ef_io__gpiov2_pad:

OpenROAD GUI KLayout
Image Image

This can lead to DRC violations and even to shorts between nets:

DRC violation short
Image Image
Expected Behavior

Implement support for polygons, or convert polygons to rectangles.

Based on the discussion at https://github.com/The-OpenROAD-Project/OpenROAD/issues/556, I thought this was already the case.

Environment
Latest OpenROAD
To Reproduce

Here is the LEF file: sky130_ef_io.zip

Please let me know if you need a full reproducible with ODB.

Relevant log output

Screenshots

No response

Additional Context

No response

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.

Research direction

Start with the attached sky130_ef_io.zip LEF input and compare its POLYGON statements with the geometry shown in OpenROAD GUI and KLayout. Reproduce the missing geometry in the latest OpenROAD, then verify that polygon support or rectangle conversion preserves the shape and avoids the reported DRC violations and shorts.

Written by the indexing model from the issue text.

Assessment

Domain
tooling
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
52/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.