Python variable or PyMTL HW module

[yuqisun]

Hi @tancheng ,

Continue on this topic, a question: how to tell if python variable or PyMTL HW module is required, i.e, does python variables work for below RTL?

XbarBypassQueueRTL.py#L32-L33

s.num_inports = num_inports
s.num_outports = num_outports

[tancheng]

It works. My understanding is: if you put s. there, then there will be real HW generated, in this case, two wires are generated/instantiated. On the other hand, if you just use num_inports w/o s. here, then the two wires won't exist.

[yuqisun]

So Python variable should be prioritize used to save HW cost.