The vlog95 code generator collects all the constant assignments to a net
within each scope and then emits them. The old code only recorded the
ivl_signal_t for each constant assignment, which meant it had to iterate
through the nexus pointers in the assicated nexus to find the constant.
When there were multiple constant assignments to the same net, it needed
to record which assignments had already been emitted, which it did by
keeping a count in the nexus private data and skipping that many constants
on each successive assignment. However the count did not get reset after
emitting all the assignments in that scope, so if there were assignments
to the same net made in another scope, the count would already be positive
and those assignments would also be skipped.
This could probably have been fixed by clearing the nexus private data
after processing the constant assignment list for each scope, but it is
more efficient to record the ivl_nexus_ptr_t for each constant along with
the ivl_signal_t, eliminating the need to search for the associated nexus
pointer.
This includes support at the parser (pform) through enaboration
and the netlist format for the break and continue statements.
Elaboration actually already worked for for-loops, but since the code
generators need more information, this is a rewire of that support to
be explicit about for-loops. This means they are not rewritten as fancy
while loops. The code generators will have to handle that.
Given the elaboration of for-loops now work, write the vvp code generator
support needed to implement it.
Now that for-loops are presented as for-loops to the code generator, the
vlog95 code generator doesn't need to infer them anymore. Generate the code
more directly.
Also update the tests list so that the vlog95_reg tests all pass.
The vlog95 backend currently ignores the sign of a function return value.
Check for it and if `-pallowsigned=1` was specified emit the `signed`
keyword. Otherwise report an error.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog supports type parameters. These are similar to value
parameters, but they allow to pass a type to a module or similar when
instantiating it.
E.g.
```
module A #(parameter type T = int);
endmodule
module B;
A #(.T(real)) i_a;
endmodule
```
Add support for handling type parameters.
For the vlog95 and vhdl backends type parameters, similar to typedefs, get
replaced with their actual value. For modules with non-local type
parameters for each module instance a unique module or architecture is
generated with the actual type.
Querying type parameters through VPI is not yet supported.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
For modules with parameters the vlog95 backend generates one module
declaration for each module instance. This is done so that different values
for the module parameters can be supported.
Local parameters are guaranteed to have the same value for all module
instances though. Add support for detecting the case that all module
parameters are local parameters and in that case only create one shared
module declaration. This is similar to what the vhdl backend does.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
While a package can not have logic defined in it. It can have
variables with initializers. These initializers currently get
ignored when converting the package to a module in the
vlog95 backend.
Make sure packages are treated the same as modules here and
that the initializers are turned into initial blocks in the
generate vlog95 code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Add support for detecting when to add a $signed() or $unsigned() to
create a self-determined context. This makes the test in the test suite
pass, but there could still be issues
Since parameters are now passed by reference use that information to print
the parameter name in a select vs trying to figure it out by searching the
scope looking for a parameter with the same file, line and value information.
Only print the $signed() may need to be removed messages for a select
expression that will actually be cast to signed.
Use the actual parameter information to warn that -pallowsigned=1 is needed
for a parameter when the LSB > MSB.
The actual signal code is trivial, but the emit expression code needed
to be enhanced to pass a flag that says if one of the arguments in a
binary (except the shifts) or ternary (excluding the condition) context
is unsigned. This information is used to prevent emitting an explicit
$unsigned() for a signal that is used in this context since it will be
implicitly cast to unsigned.
This patch finishes the code needed to translate a SystemVerilog package to a
module with a special name. It also adds code to report that class scopes are
not supported and treats both a class and package as a top level scope.
There are limitations with this since the compiler does not pass all
the information that was present in the original source, but it is enough
to get a valid simulation result. It is not enough for timing analysis!
specparams are also incorrectly translated to parameters so they show up
in the wrong place.
In SystemVerilog a task or function can initialize a variable in a task or
function. In Icarus this is done by creating an initial block that does
the assignment. We can translate this by emitting the initial block in the
enclosing module scope. This is not 100% correct since SystemVerilog
requires the initialization to be done before the other initial/always
blocks are processed. For SystemVerilog the current Icarus behavior is
incorrect, but even if it had a new process type that ran before the other
ones the best I can do for vlog95 is emit it before the normal module
processes which currently works.
We can not convert SystemVerilog strings or dynamic arrays to valid vlog95.
This patch adds an error message that they are not supported. There are still
issues with converting some of the dynamic array constructs (the compiler
crashes), but the message is printed before the crash.
This patch adds support for SystemVerilog packed arrays and adds sorry
messages for generate blocks as well as the new SV final and
fork/join_any/join_none statements.
Rework the nexus emitting code to correctly translate most I/O ports.
Fix a few other expression issues uncovered when port translation was
done correctly. Ignore and warn that the SV ++/-- operators and enum
types are not translatable. More updates of the nexus debug code.
This patch adds support for correctly handling most unconnected ports.
Most important is top level ports that are the root of the conversion.
This patch also adds support for emitting more signed constructs when
they are requested. $signed() and $unsigned() are still not supported
or recognized as an error when not emitting signed constructs.
This patch adds a flag -pallowsigned=1 to the vlog95 converter that
tells it to allow signed signals. There is currently no code to check
for and warn/emit the $signed() and $unsigned() system functions. I
need to determine if >>> emitting should also be controlled by the
allow signed flag.
This patch adds support for emitting escaped identifiers and adds
code to correctly emit most module port expressions/definitions.
There are some minor code optimizations/cleanup included as well.
This patch adds support for emitting fixed CA selects (zero based
variable bit and array selects also work), emitting a for statement
as a single statement and fixes for numerous little bugs. It also
adds the start of emitting module port information.
Martin Whitaker
Stephen Williams
Cary R
Lars-Peter Clausen
Martin Whitaker
Larry Doolittle