This patch implements the $countdrivers system function. It does not
yet support wires connected to islands (and outputs a suitable "sorry"
message when this is detected).
To implement the $countdrivers system function, we need to be able to
find all the driver values for a given wire. Currently, if a wire has
has more than four drivers, the compiler builds a resolver tree out
of 4-input nodes to resolve the driven values, and there is no way at
run time to work back from the output node to the original driver
values. This patch moves the implementation of the resolver tree into
a single vvp functor (using a mechanism similar to wide functors to
support more than 4 inputs), thus gathering all the driver values into
a single place.
This patch splits any VVP net functor that needs to access both
statically and automatically allocated state into two sub-classes,
one for handling operations on statically allocated state, the
other for handling operations on automatically allocated state.
This undoes the increase in run-time memory use introduced when
automatic task/function support was first introduced.
This patch also fixes various issues with event handling in automatic
scopes. Event expressions in automatic scopes may now reference either
statically or automatically allocated variables or arrays, or part
selects or word selects thereof. More complex expressions (e.g.
containing arithmetic or logical operators, function calls, etc.) are
not currently supported.
This patch introduces some error checking for language constructs
that may not reference automatically allocated variables. Further
error checking will follow in a subsequent patch.
This patch makes .part/pv strength aware, resolv vec8_pv
aware. vvp_net_fun_t adds vec8_pv as a virtual function
with an appropriate error default. vvp_fun_signal should
full support vec8_pv (not tested and may not be needed).
The vvp_vector8_t constructor and destructor involve memory allocation
so it is best to pass these objects by reference as much as possible.
Also have the islands take more care not to perform resolution if the
inputs aren't really different.
NOTE: This is a port of commit 2f4e5bf5b6
from the "performance" branch, without the resolver scheduling changes.
This was causing test suite variances with pr1820472.v. It looks like
there might be a race in that program anyhow, but for now leave out the
resolver scheduling changes so that the rest of this commit can go in.
Remove dependencies on vvp_bit4_encoding outside of the vvp_net
core types. The table_functor_s class was the worst offfender and
was barely used, so it is now removed completely. There are a few
opcodes in vhtread.cc that also make vvvp_bit4_t encoding
assumptions (and used casts) and those have been fixed. There
were also various VPI interface functions that are fixed.
The runtime is a vvp runtime engine debug aid that allows for
detailed dump into a debug log. The trace is enabled by setting
the VVP_DEBUG variable and activating specific debug messages
in the vvp source.
Signed-off-by: Stephen Williams <steve@icarus.com>
Cary R
Arun Persaud
Martin Whitaker
Martin Whitaker
Stephen Williams
Larry Doolittle
steve