Internally void function calls are modeled as task calls. But unlike task
calls, access to a signal inside a void function is supposed to contribute
to the sensitivity list of an always_comb block.
Make sure that the same logic applied for non-void functions is also
applied for void functions.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The fix for the compiler hang when calculating the sensitivity list
for an always_comb construct containing recursive function calls
could cause the compiler to ignore sequential calls to the same
function, and thus not add the arguments of those calls to the
sensitivity list.
Internally, treat the "$" as a special expression type that takes
as an argument the signal that is being indexed. In the vvp target,
use the $last system function to implement this.
This generates an EQZ LPM device that carries the case-z-ness to
the code generator.
Also add to the vvp code generator support for the EQZ device so
that the synthesis results can be simulated.
Account for the wildcard devices in the sizer.
This required keeping for-loops as actual things through the
netlist form so that the synthesizer can get at and understand
the parts of the for-loop. This may improve vvp code generation
in the future, but for now continue to present to the vvp code
generation the block-while form.
For synthesis we remove the output set of signals from the input set to
remove temporaries from the final sensitivity set. The @* construct also
uses the input sensitivity list, but because it can include statements
that cannot be synthesized we should not calculate the output set for this
case. Not find the output set is also a speed enhancement since the output
set was already being ignored later in the code for this case.
Add properties to the classes, and elaborate expressions that
have class properties. Describe class object property references
all the way down to the stub target.
This gets the enumeration type through to the ivl_target API so
that code generators can do something with it. Generate stub
output with tgt-stub, and generate the proper vvp run time to
make simple enumerations work from end to end.
System tasks and functions can be defined to have NULL arguments.
This patch makes the @* sensitivity list calculation skip these
NULL (constant) arguments.
This patch covers more than it should. It removes many of the -Wextra
warnings in the main ivl directory. It also makes some minor code
improvements, adds support for constant logicals in eval_tree (&&/||),
adds support for correctly sign extending === and !==, it starts to
standardize the eval_tree debug messages and fixes a strength bug
in the target interface (found with -Wextra). The rest of the warnings
and eval_tree() rework will need to come as a second patch.
This patch adds two new warning classes that can be enabled or
disabled via the -W command line option. The first controls
whether a warning is generated if a part select within an
always @* statement causes the entire vector to be added to
the implicit sensitivity list. The second controls whether a
warning is generated if a word select within an always @*
statement causes the entire array to be added to the implicit
sensitivity list. The first class is not automatically enabled
by -Wall, the second class is.
An implicit sensitivity list that has selects (bit, part, indexed
part or array) will include more than the user expects so print a
warning to let them know what will happen. Other simulators have
the same behavior, but I believe this is incorrect and needs to
be fixed to only include the appropriate parts. The warnings can
go when we fix this functionality, but we need them now to warn
the user that they may not be getting what they expect. One other
simulator warns for array selects.
This patch also adds the array index to the sensitivity list.
Add code to check for a plain delay statement (just a delay).
When one is found generate a null statement and do not add it
(the null statement) to result.
Because Icarus tries to elaborate as much as it can even after
an error has occurred we need to check for these errors during
elaboration. This patch prevent an undefined identifier from
crashing the compiler.
Detect function call expressions that turn out to be calls to the
access function of a nature. Elaborate the access function and stub
the emit code. This gets the access function just short of the code
generator.
Rework the handling of file names to use a perm_string heap to hold
the file names, instead of the custom file name heap in the lexor.
Also rename the get_line to get_fileline to reflect its real duties.
This latter chage touched a lot of files.
@* was only expanding to input nets. nex_input() for blocks was removing
any output net that was also an input. There was also a bug in how output
nets were removed. Only outputs currently defined were removed from the
input list.
always @(*) begin
y = a;
z = y;
end
would report "a" as an input. While
always @(*) begin
z = y;
y = a;
end
would report both "a" and "y" as inputs.
To fix this all nex_inputs now take a flag that when true (the default)
correctly removes any output from the input list. Both the above cases
will now return "a". If the flag is false outputs which are also inputs
will be included in the input list. This is what the @* elaboration code
uses to get the correct sensitivity list.
more general concept of arrays. The NetMemory and NetEMemory
classes are removed from the ivl core program, and the IVL_LPM_RAM
lpm type is removed from the ivl_target API.
Cary R
Lars-Peter Clausen
Martin Whitaker
Henry Wong
Stephen Williams
Arun Persaud
Larry Doolittle
steve