[AP][GlobalPlacement] Improved Partial Legalizer Legality #2942
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Updated the partial legalizer to now take into account block types when spreading blocks. This will create windows around overfilled bins that is aware of which block types are overfilled and how large the window needs to be to accomodate them. It also takes these block types into account when spreading to only allow blocks to spread into sub-windows that they can exist in. This improves quality but was detremental to performance, so some performance improvements were needed. To improve the performance of the partial legalizer, I split the problem into groups of models which must be spread together. This allows us to create tighter windows and can make some parts of the legalizer more efficient. Create a model grouper class which forms the model pack patterns into a graph and find disconnected sub-graphs to form the model groups. Also improved the window generation by pre-clustering the overfilled bins before creating the windows. This sped up the window generation code since less windows overlap.
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Updated the partial legalizer to now take into account block types when spreading blocks.
This will create windows around overfilled bins that is aware of which block types are overfilled and how large the window needs to be to accomidate them. It also takes these block types into account when spreading to only allow blocks to spread into sub-windows that they can exist in.
This improves quality but was detrimental to performance, so some performance improvements were needed.
To improve the performance of the partial legalizer, I split the problem into groups of models which must be spread together. This allows us to create tighter windows and can make some parts of the legalizer more efficient. Create a model grouper class which forms the model pack patterns into a graph and find disconnected sub-graphs to form the model groups.
Also improved the window generation by pre-clustering the overfilled bins before creating the windows. This sped up the window generation code since less windows overlap.
Due to the improved flat placement generated by the Global Placer, tuned the APPack parameters to account for this.
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