If someone accidentally makes a parameter depend on itself
we need to report this not crash. This patch fixes the crash
and prints an appropriate string of messages to figure out
the loop. Icarus currently supports forward references of
parameters so more complicated loops can be created. These
are also caught.
To prevent a force from back propagating we need to keep a BUFZ
that represents a continuous assignment between two nets. This
only effects continuous assignments of the form assign out = in.
In general these are fairly rare so keeping them has minimal
impact on the simulation speed.
Add code to print a warning if the user tries to use the -S flag.
We need this warning since synthesis is not currently being actively
maintained or supported in any branch after V0.8.
For example:
-- Generated from Verilog module child (vhdl_tests/generics.v:30)
-- MY_VALUE = 3
entity child is
To make it clear which values were used for this entity.
This changes the implementation of $display/$write to use VHDL
report statements rather the the std.textio functions. The code
produced is simpler and more like what a real VHDL designed would
write. However it no longer exactly matches the Verilog output as
most VHDL simulators prepend the text with simulation time, entity
name, severity level, etc. There is a corresponding change in
ivtest to support this.
Previous we generated a "wait for 0 ns" statement after
every blocking assignment that wasn't the last statement
in the process. While this implements the Verilog semantics,
it generates excessive waits, and cannot usually be synthesised.
This patch only generates "wait for 0 ns" statements when it
cannot be avoid (e.g. when the target of a blocking assignment
is read in the same process).
An example:
begin
x = 5;
if (x == 2)
y = 7;
end
Becomes:
x <= 5;
wait for 0 ns; -- Required to implement assignment semantics
if x = 2 then
y <= 7; -- No need for wait here, not read
-- wait for 0 ns (previously)
end if;
This patch adds a check in the vvp back end that a uwire has
at most one driver. Previously this was just converted (with
a warning message) to a wire just after elaboration.
This patch adds the ability to call a system function as a task for
the SystemVerilog generation (-g2009). The return value is really
calculated, but it is ignored.
E.g. $signed(x) > y with x, y different sizes should be
resize(signed(x), N) > y
Not
signed(resize(x, N)) > y
As this does not treat the sign bit correctly. Was causing
the signed5 test to fail.
Added 'expr_wid' parameter to calls to 'eval_expr()' within
PEBinary::elaborate_eval_expr_base_()'. This makes a specific problem
go away and may even be the correct thing to do.
This patch adds support for a UDP with variable delays. In the process the
intrinsic support for delays was removed from the UDP functor and replaced
with a call to the .delay functor. Both a normal gate and a UDP now use the
same code to generate the delay.
This patch adds checks that the delay count is correct for the
various gates and adds support for a missing variable decay
time. For this case the decay time is the minimum of the rise
and fall times. This is denoted by setting the decay variable
to 0 in the vvp file. vvp notes this and sets an ignore decay
time property in the base delay. This turns off the ability
to set the decay time and the minimum delay calculation will
also update the decay time.
These checks are not needed since we have already verified that
we have a 64 bit immediate value. This is likely old code that
should have been removed when the original functionality was
changed.
This patch pushes delays for tranif gates to the code generator.
We still need to add checks for the number of delays, etc. For
now an error message is printed when a tranif gate is given a
non-zero delay.
This patch modifies the real ternary operator code to support
unlimited tail recursion without overflowing the thread
registers. Head recursion is still limited by the available
registers.
It fixes the thread word checks to use a new define that has
the correct number of thread words (16). It adds a message
instead of just an assert if the thread words are exhausted.
And it also changes some of the error messages to use vvp.tgt
in the message to be consistent with the other messages.
Elaborate conditional assignments with BUFZ devices that do *NOT*
preserve strengths. Add a BUFT (transparent) device that can be
used in those cases where I really need a transparent buffer.
We only need to set the width of a multiple if the width is greater
than zero and if the expression is vectorable. This matches what is
done for addition.
A real delay must be scaled and rounded using the local precision
before it is finally scaled to the simulation time units. This
patch fixes the compiler to do this correctly or generate the
correct code for run time calculated delays. Delays in a CA
already worked correctly. The run time was also fixed to scale
modpath (SDF back annotation) delays correctly.
This patch modifies the vvp main code to cleanup if there was an
error compiling the input file. There are still a few issues, but
this takes care of most of them.
The error routines for task and function definitions were incorrectly
popping the scope. This should not be done since no scope was pushed.
Also assert that the current_task/function is 0 to catch that kind of
error like the other definition rules.
This patch adds two new opcodes and the infrastructure needed to call
system functions as tasks. The normal %vpi_call will generate an error
if a system function is called as a task. %vpi_call/w will generate a
warning and will ignore any value returned by the function. %vpi_call/i
will ignore the system function return value and will not print a
message. Adding this is a feature request and is supported in
SystemVerilog. Next I need to add flags to control this depending on
the compiler generation and possibly other flags.
I may leave the cast to void (%vpi_call/i) functionality unimplemented
for now.
This patch caches the vpi_call error messages (task/function does
not exist, task being called as a function and function being
called as a task). This allows us to display the file name and line
number information for the invalid usage.
When pushing the current file path we need to get past any `define
expansions that have been pushed onto the stack to find the real
file path.
This patch is partially based on a patch submitted by Steve Tell.
Cary R
Nick Gasson
Stephen Williams
Patrick Doyle