Now that we only call `bitvectorize()` in non-const methods, we can move the casting-away-const to only happen
in `bitvectorize()`, which is deprecated so only some plugins (maybe) are using it.
This means `const` `Const` methods don't change the underlying data, which means
they'll be safe to use from multiple threads if/when we want to do that.
Still unsupported:
- wide muxes (`$_MUX16_` and friends)
Partially supported types have comments in `test_cell.cc`.
Fix `CellTypes::eval() for `$_NMUX_`.
Fix `RTLIL::Cell::fixup_parameters()` for $concat, $bwmux and $bweqx.
dict is pretty slow when you don't ever need to iterate the container in
order. And the hashfunction for char* in dict hashes for every single
byte in the string, likely doing significantly more work than std::hash.
If you have a large design with a lot of modules and you use the Verilog
backend to emit modules one at a time to separate files, performance is
very low. The problem is that the Verilog backend calls `design->sort()`
every time, which sorts the contents of all modules, and this is slow
even when everything is already sorted.
We can easily fix this by only sorting the contents of modules that
we're actually going to emit.
Used to select all modules including boxes, set when both `full` and `boxes` are true in the constructor, pulling down `full_selection`.
Add `Selection::selects_all()` method as short hand for `full_selection || complete_selection`.
Update selection operations to account for complete selections.
Add static methods to `Selection` for creating a new empty/full/complete selection to make it clearer to users when doing so.
Use said static methods to replace most instances of the `Selection` constructor.
Update `Selection::optimize` to use
New methods on Design to push/pop selection instead of accessing the selection stack directly. Includes methods for pushing a full/complete/empty selection.
Also helper methods on modules to check `is_selected` and `is_selected_whole`.
Now uses two enums, one to control whether or not to include partially selected
modules (and what to do if they are encountered), and one to control whether or
not to include boxed modules (and what to do if they are encountered).
Mark Design::selected{modules, whole_modules}() deprecated and make them
provide warnings on boxes. There are a lot of places that use them and I can't
always tell which ones support boxed modules and which don't.
