The Verilog-A abs(), min() and max() functions can be converted if the
expressions do not have side effects. Also note the new, null and class
property operators from SystemVerilog are not supported.
SystemVerilog allows a function to be called without an assignment for
the return value. This patch adds a warning that Icarus does not currently
support this and provides a place to add this functionality later.
This patch implements the evaluate_function method for the NetEBBits,
NetEBDiv, NetEBLogic, NetEBMinMax, and NetEBPow classes. It also
factors out some common code into the NetEBinary class.
Currently, when a variable expression is passed to a system task,
the expression value is stored in thread memory. Values stored
in thread memory cannot safely be passed to $strobe or $monitor,
because the thread memory may get reused or deallocated before
the $strobe or $monitor task actually executes. As a temporary
measure, we just trap this case and terminate with a "sorry"
message. A proper fix would require the expression value to be
calculated at the time the $strobe or $monitor executes, not at
the time it is called.
This is rather a pointless sort of thing, but it does turn from
from time to time, for example when constant literals (with no x or
z bits) are given strengths. So handle .net8/2s and .net8/2u the
same as .net8.s and .net8 objects.
If a strength aware net has an unambiguous HiZ1 strength, VVP treats
it as a logic '1'. It should be treated as a logic 'z'. An ambiguous
HiZ1/HiZ0 strength should also be treated as a logic 'z'.
L-value bit selects were incorrectly converting an undefined index to 0.
L-value part selects were asserting if an undefined index was given.
This patch unifies how all these are handle (including indexed part selects).
The base is set to an undefined value and an appropriate width is used.
A warning message is always printed since this is not a simple out of
range issue. It is the responsibility of the code generator to skip the
assignment, but we always want to execute the R-value since it could have
a side effect.
When VVP compiles a .array statement for a net array, it does not
know the data type, so initialises the array signed_flag to false.
We need to set the signed_flag to the correct value once we know
the data type, to allow the VPI routines to correctly format the
data.
When checking with valgrind clean up the following:
The arguments for invalid task/function calls.
The simulation callback queues (only needed when the runtime aborts).
Call pthread_exit(NULL) just before exiting to cleanup dynamic loading.
Cary R
Martin Whitaker
Stephen Williams