Post-routing synchronization cannot handle output pins

[tangxifan]

Post-routing synchronization is under development to update packing results with the net/pin remapping due to routing optimization. However, current fix-up methodology is applicable to the net remapping on input pins. Any remapping on output pins cannot be fixed.

Expected Behaviour

The post-routing synchronization should work for both input/output pins in any pin equivalence type.

Current Behaviour

Current fix-up methodology is applicable to the net remapping on input pins.

Possible Solution

A thorough and clean solution is to run a repack based on previous packing results and current routing results.

• The pb_graph_node should be re-placed subject to routing results when instance pin equivalence is enabled.
• A detailed routing inside the blocks should be called to ensure valid local routing results
• New packing results should be used in timing analyzer.
• New packing results should be outputted to a .net file

Steps to Reproduce

See the comments and codes in the vpr/src/pack/post_routing_pb_pin_fixup.cpp of the pull request #1355 .

Context

This will cause wrong bitstream generation due to a mismatch between packing results and routing results.

Your Environment

• VTR revision used: VPR master
• Operating System and version: CentOS 7
• Compiler version: gcc-8.4

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[github-actions]

This issue has been marked stale for 15 days and has been automatically closed.