Why did we need this? (what does this change enable us to do)

This enables the specification of place constraints of non-IO tiles, necessary to solve issues like f4pga/f4pga-arch-defs#1182

What did it change?

initial placement of fixed IOs

Should it be merged upstream - if not, when can we delete it?

No, this is a temporary solution. The issue should be solved in a more proper way, but it requires consultations with vtr-devs to get to the final solution.

What is needed to get this merged / deleted?

Update VtR with an alternative solution, (e.g. enable usage of placer constraint files).

• is the implementation work to make suitable for merging / deletion completed?
• Is there an associated test?
• is this currently part of the Conda package?
• is this properly cleaned up in our local repositories?

Tracker / branch / PR & other useful links

f4pga/f4pga-arch-defs#1182