- Attempt to lookup a derived module if it potentially contains a port
connection with elaboration ambiguities
- Mark the cell if module has not yet been derived
- This can be extended to implement automatic hierarchical port
connections in a future change
I think the code is now a bit easier to follow (and has lost some
levels of indentation!).
The only non-trivial change is that I removed the check for
cell->type[0] != '$' when deciding whether to complain if we couldn't
find a module. This will always be true because of the early exit
earlier in the function.
There should be no functional change, but this splits up the control
flow across functions, using class fields to hold the state that's
being tracked. The result should be a bit easier to read.
This is part of work to add bind support, but I'm doing some
refactoring in the hierarchy pass to make the code a bit easier to
work with. The idea is that (eventually) the IFExpander object will
hold all the logic for expanding interfaces, and then other code can
do bind insertion.
- Signed cell outputs are sign extended when bound to larger wires
- Signed connections are sign extended when bound to larger cell inputs
- Sign extension is performed in hierarchy and flatten phases
- genrtlil indirects signed constants through signed wires
- Other phases producing RTLIL may need to be updated to preserve
signedness information
- Resolves#1418
- Resolves#2265
The only difference between "RTLIL" and "ILANG" is that the latter is
the text representation of the former, as opposed to the in-memory
graph representation. This distinction serves no purpose but confuses
people: it is not obvious that the ILANG backend writes RTLIL graphs.
Passes `write_ilang` and `read_ilang` are provided as aliases to
`write_rtlil` and `read_rtlil` for compatibility.
This code originally comes from commit 458a940. When an interface is
used via a modport, code in genrtlil.cc sets '\\interface_type' and
'\\interface_modport' properties on the wire.
In hierarchy.cc, we pick up the modport name and add it to a dict
called modports_used_in_submodule (that maps connection source to
modport name).
Before this patch, the modport name is retrieved as a strpool and then
iterated over in an arbitrary order, discarding all entries but the
last. In practice, the pool will always have 0 or 1 entries because
the string used to construct it is a valid identifier, so doesn't
contain any pipe symbols.
This patch changes the code to retrieve the modport name as just a
string. This will have the same effect in practice, but may be a bit
less confusing!
The code also gets moved down closer to where the result is used,
which might be a bit more efficient since we won't always get as far
as the check.
The patch also removes some commented-out code, which I think was
intended to add some typechecking at some point, but was never
implemented. Since this dates back to October 2018, I think it makes
more sense to just take it out.
Zachary Snow
Rupert Swarbrick
Claire Xenia Wolf
Miodrag Milanovic
whitequark
clairexen
Marcelina Kościelnicka
Alberto Gonzalez
Eddie Hung
Claire Wolf
David Shah