Rather then join islands while branches are initially created, save the
island creating for the end. This way, the process is actually recursive
and greedy, reliably collecting branches into islands without conflict.
Fold the bi-directional part select into the pass switch (tran) support
so that it can be really bi-directional. This involves adding a new
tranvp device that does part select in tran islands, and reworking the
tran island resolution to handle non-identical nodes. This will be needed
for resistive tran devices anyhow.
NetTran devices must be collected into islands because they are all
a bi-directional mass. This is how vvp will process them and the code
generator will need a head start organizing them.
This involves defining the API for switches and cleaning up the
elaborated form to match the defined ivl_target API. Also add t-dll
code to support the ivl_switch_t functions, and add stub code that
checks the results.
The tran devices include tran, rtran, tranif0/1 and rtranif0/1. These
are all elaborated as options on a NetTran device. It is still not
clear the best way to present tran devices via the ivl_target.h API.
Stephen Williams