SystemVerilog defines different levels of type compatibility.
* Matching
* Equivalent
* Assignment compatible
* Cast compatible
At the moment the `nettype_t` has only one type compatibility test. It is
used to check assignment compatibility when assigning to a dynamic array,
queue or class.
The current implementation rejects a few cases that should allowed and
allows a few cases that should be rejected.
Dynamic arrays and queues are assignment compatible if their element types
are compatible. And two packed types are equivalent if they are both
2-state or 4-state, both signed or unsigned and have the same packed with.
In the current implementation the sign is not considered and instead of
checking if the packed width is the same it checks that the dimensions are
identical.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently only the netvector_t type implements the get_scalar() method. To
check whether a type is scalar it is first cast to netvector_t and then the
method is called.
But there are other types, such as areal that can also be scalar. To
support indicating that a real type is scalar add a virtual get_scalar()
method to ivl_type_s, which is the base class for all types.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Use the common data_type_or_implicit rules to support type
definitions for parameters. This eliminates a bunch of special
rules in parse.y, and opens the door for parameters having
more complex types.
The netparray_t::slice_dimensions bug was the most insidious and
caused all manner of confusion. Also fix some other packed array
and unpacked array (and mixed) indexing calculations.
Lars-Peter Clausen
Stephen Williams
Martin Whitaker
Larry Doolittle
Cary R
Arun Persaud