The last user of the `PExpr::is_the_same()` method was removed in commit
37b60a4c52 ("Clean up interface of the PWire class").
Remove the method.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog supports sign cast where it is possible to change the
signedness of an expression. Syntactical it is similar to width or type
casting, except that the keywords 'signed' or 'unsigned' are used in front
of the cast operator. E.g.
```
logic [3:0] a = 4'b1000;
logic [7:0] b = signed'(a); // b is 8'b11111000;
logic signed [3:0] c = 4'b1000;
logic signed [7:0] d = unsigned'(c); // d is 8'b00001000;
```
As noted by the LRM section 6.24.1 ("Cast operator") applying a sign cast
to an expression is equivalent to calling the $signed() and $unsigned()
system functions on the expression.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The signedness of an expression can change depending on its context. E.g.
for an arithmetic operation with one unsigned operand all operands are
treated as unsigned.
This is currently not considered when accessing class properties. This can
lead to incorrect behavior with regards to sign extension.
E.g. the following will print 4294967295 rather than 65535.
```
class C;
shortint x = -1;
endclass
...
C c = new;
$display(c.x + 32'h0);
```
Furthermore the return value is not expanded to the width of its context.
This can cause vvp to crash with an exception when it expects a vector on
the stack to have a certain width. E.g.
```
class C;
shortint x = -1;
endclass
...
C c = new;
int x;
bit a = 1'b1;
x = a ? c.x : 64'h0;
```
Solve both of this by using `pad_to_width()` on the property expression if
it is a vectorable type. Since any identifier, not just class properties,
need to have this done insert this on the common path and remove the
`pad_to_width()` call on individual paths.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The signedness of an expression can change depending on its context. E.g.
for an arithmetic operation with one unsigned operand all operands are
treated as unsigned.
For methods, both on built-in SystemVerilog types as well as user defined
classes, this is currently not considered. This can lead to incorrect behavior
if the value is sign extended.
E.g. the following will print 4294967295 rather than 65535.
```
shortint q[$];
q.push_back(-1);
$display(q.pop_front() + 32'h0);
```
Furthermore the return value is not expanded to the width of its context.
This can cause vvp to crash with an exception when it expects a vector on
the stack to have a certain width.
E.g.
```
int d[];
longint x;
bit a = 1'b1;
x = a ? d.size() : 64'h0;
```
Solve both of this by using `pad_to_width()` on the method return value if
it is a vectorable type. Since any function call, not just methods, needs
to have this done to its return value insert this on the common path.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
It is allowed to access a constant declared in a class scope, such as a
enum value or parameter, on an object of that class type. This is described
in section 8.5 ("Object properties and object parameter data") of the LRM
(1800-2017).
E.g.
```
class C
enum { A } e;
endclass
C c = new;
c.e = c.A;
```
Support this by in addition of searching for class properties on the object
also search for constants in the class scope.
A bit of refactoring is needed around the parameter elaboration functions
since they expect a non-const NetScope, but for classes we only have a
const scope available.
The non-const scope is needed to be able to mark specparams as
non-annotatable. Since classes can't have specparams this part is factored
out into a separate function the NetScope parameter for the shared
functions is made const.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently explicit cast is supported to atom2 and vector types. packed
struct, packed array and enum are not supported.
An explicit cast to packed type works the same for all packed types though.
Add support for handling also packed structs, packed arrays and enums by
make the code more generic and querying the packed base type from the
ivl_type_t.
To correctly handle enums a bit more work is necessary, which will be done
in a follow up patch.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
There are too many ad hoc handlers of symbol_search partial results.
Rewrite symbol_search to clean up things like partial results and
member/method detections. Use this reworked symbol_search function
to rewrite expression elaborate for the PECallFunction expressions.
Parameters can have string type and do the usual string stuff,
and also implement some of the string methods on string parameters
so that they evaluate down to constants.
Use the common data_type_or_implicit rules to support type
definitions for parameters. This eliminates a bunch of special
rules in parse.y, and opens the door for parameters having
more complex types.
We don't support evaluating user-defined system functions at compile
time. If possible, defer evaluation until run time. If used in a
constant expression, output a "sorry" message.
This gets nested l-values to (but just short of) the ivl_target API.
Now the elaborator can process nested l-values, but I haven't figured
out how to present that at the ivl_target.h API.
It is better to leave the handling of PChainConstructor calls to
the elaboration, instead of stripping them out early. This allows
for handling the arguments of the chain constructor in the correct
scope.
This includes adding support for returning strings from functions,
adding initializing new darray with array_pattern strings, and
assigning an array_pattern of strings to a preallocated darray.
Also fix up support for initializing array with simple string
expression.
For variable parameter selects (indexed and bit) pass the value being
selected as a parameter reference instead of just a numeric constant
so it is easy to get the underlying parameter information.
Move the parameter bit select code into its own routine and cleanup
the remaining general code.
This should not effect the VVP code, but the ivl_expr_parameter(<expr>)
routine can be used to get at the actual parameter information in the
vlog95 target.
Static properties are like variables in a named scope.
Detect these variables during elaboration so that the
code generator just sees them as variables.
For constant bit/part selects, issue a warning if the select is out
of range or an undefined value. In any case, the RHS value should be
discarded, and the actual assignment should be skipped.
For constant word indices, issue a warning if the index is out of
range or an undefined value. In any case, the RHS value should be
discarded, and the actual assignment should be skipped.
Stephen Williams
Lars-Peter Clausen
Martin Whitaker
Cary R
Maciej Suminski
Larry Doolittle