project compilation is taking forever to finish

If it wasnt synthesisable, it would have failed fairly quickly.

These long compilations often stem from RAMs not be inferred using embedded memory, but being built from registers instead. These can make compillation times explode - so make sure your rams are actually rams

Other things that increase compile time:

1. Not enough system ram, as virtual ram is very very slow

2. Higher resource usage. Using more than 50% of the chip can make compillation take longer

3. Effort multipliers tend to increase compile time and after about 5x they tend to increase compile time without much benefit.

Assuming you have enough RAM for whatever chip you're building for, a full chip (>50% often counts as "full" for routing purposes) should complete in hours, not days.