LVS feature request: same device class, different extractors

[klayoutmatthias]

Sometimes it's useful to have different device extractors producing the same device model with different algorithms.

This will also allow the device combination algorithm to join such devices.

Proposal: extractors using the same model name shall share the same model. Right now, it's not possible to give two extractors the same name.

[klayoutmatthias]

2r.zip

To see the desired effect, the attached layout has two kind of devices (both "RES"). With this feature, we could use this extraction run:

rmarker = input(1, 0)
poly = input(2, 0)
diff = input(3, 0)
contact = input(4, 0)
metal = input(5, 0)

poly_cap = poly - rmarker
poly_res = poly & rmarker
diff_cap = diff - rmarker
diff_res = diff & rmarker

extract_devices(resistor("RES", 50), { "R" => poly_res, "C" => poly_cap })
extract_devices(resistor("RES", 150), { "R" => diff_res, "C" => diff_cap })

connect(poly_cap, contact)
connect(diff_cap, contact)
connect(contact, metal)

puts netlist.to_s

netlist.simplify

puts netlist.to_s

In the second netlist, the resistors should be combined serially.