✨ Parameter to move inputs/outputs to top/bottom border after hexagonalization

[simon1hofmann]

Description

Parameters to move inputs to top border or outputs to the bottom border after hexagonalization

Checklist:

• The pull request only contains commits that are related to it.
• I have added appropriate tests and documentation.
• I have added a changelog entry.
• I have created/adjusted the Python bindings for any new or updated functionality.
• I have made sure that all CI jobs on GitHub pass.
• The pull request introduces no new warnings and follows the project's style guidelines.

[codecov]

Codecov Report

Attention: Patch coverage is 98.48101% with 6 lines in your changes missing coverage. Please review.

Project coverage is 98.19%. Comparing base (0ee0f3d) to head (324eaa2).

Files with missing lines	Patch %	Lines
...on/algorithms/physical_design/hexagonalization.hpp	97.89%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #692      +/-   ##
==========================================
- Coverage   98.20%   98.19%   -0.01%     
==========================================
  Files         255      255              
  Lines       42229    42519     +290     
  Branches     1949     1989      +40     
==========================================
+ Hits        41471    41753     +282     
- Misses        758      766       +8     

Files with missing lines	Coverage Δ
include/fiction/algorithms/path_finding/a_star.hpp	100.00% <100.00%> (ø)
...on/algorithms/physical_design/wiring_reduction.hpp	98.76% <100.00%> (ø)
include/fiction/utils/placement_utils.hpp	85.71% <100.00%> (+0.71%)	⬆️
...st/algorithms/physical_design/hexagonalization.cpp	100.00% <100.00%> (ø)
test/utils/blueprints/layout_blueprints.hpp	100.00% <100.00%> (ø)
...on/algorithms/physical_design/hexagonalization.hpp	97.61% <97.89%> (-2.39%)	⬇️

... and 1 file with indirect coverage changes

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[github-actions]

clang-tidy made some suggestions

[Copilot]

Pull Request Overview

This pull request introduces a parameter to move inputs to the top border after hexagonalization and adds new tests to verify the behavior with parameters and statistics.

• Adds new tests under hexagonalization to check behavior when placing inputs in the top row
• Exports new functions (hexagonalization_params, hexagonalization_stats, and hexagonalization_route_inputs_error) in the module's init.py

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

File	Description
bindings/mnt/pyfiction/test/algorithms/physical_design/test_hexagonalization.py	New tests to verify hexagonalization with parameters and statistics
bindings/mnt/pyfiction/init.py	Updated exports to include new hexagonalization functionality

[simon1hofmann]

@marcelwa @samuelshng
Extending output wires to the bottom border is now possible using the -o flag (-o 0 for no extension, -o 1 for extending to the bottom row, and -o 2 for extending to the bottom row with planar rerouting).

For example to hexagonalize a layout and route inputs to the top row and outputs to the bottom row (allowing crossings) you can simply use: hex -i 1 -o 1.

[marcelwa]

@marcelwa @samuelshng
Extending output wires to the bottom border is now possible using the -o flag (-o 0 for no extension, -o 1 for extending to the bottom row, and -o 2 for extending to the bottom row with planar rerouting).

For example to hexagonalize a layout and route inputs to the top row and outputs to the bottom row (allowing crossings) you can simply use: hex -i 1 -o 1.

Many thanks for implementing this so quickly 🙏 from a user's perspective, I would have expected this functionality to be available via flags instead of parameters. In the current setup, a user might enter hex -i 3 -o 5, which is obviously nonsensical. Since I cannot think of a situation in which someone would want only PI wires to be crossing-free but not PO wires (or vice versa), I expected a flag-based interface like hex -i -o -p, i.e., extend PIs and POs, and do so planarly.

What do you think? Is there an argument to be had against it?

[simon1hofmann]

@marcelwa @samuelshng
Extending output wires to the bottom border is now possible using the -o flag (-o 0 for no extension, -o 1 for extending to the bottom row, and -o 2 for extending to the bottom row with planar rerouting).
For example to hexagonalize a layout and route inputs to the top row and outputs to the bottom row (allowing crossings) you can simply use: hex -i 1 -o 1.

Many thanks for implementing this so quickly 🙏 from a user's perspective, I would have expected this functionality to be available via flags instead of parameters. In the current setup, a user might enter hex -i 3 -o 5, which is obviously nonsensical. Since I cannot think of a situation in which someone would want only PI wires to be crossing-free but not PO wires (or vice versa), I expected a flag-based interface like hex -i -o -p, i.e., extend PIs and POs, and do so planarly.

What do you think? Is there an argument to be had against it?

Yes makes sense, I will update the cli accordingly. I will still leave the implementation in the C++/Python code as is to still offer the possibility of only having planar routings for either PIs or POs.

[marcelwa]

@simon1hofmann many thanks for the great addition! 🙏 I've got some minor feedback and implemented a few small inconsistency fixes myself. Additionally, there seems to be inconsistent behavior with the -p flag. Could you have a look?