Compilation Errors with $countdrivers and Specify Block Conditions

[vowstar]

Compilation Errors with $countdrivers and Specify Block Conditions

[MikePopoloski]

Fixed in d8d0237 and 9f02fd6

[MikePopoloski]

Thanks for the kind words.

There are two separate problems described here. The first is the $countdrivers function. This is not a standard SystemVerilog system function. It's described in Annex D of the LRM, which says:

The system tasks and system functions described in this annex are for informative purposes only and are not
part of this standard.

That being said, I'm not against having slang support them anyway.

Second, state dependent path conditions are described in 30.4.4.1. There is a table there, Table 30-1, which lists the valid operators, and the triple-equals operator is not in the list, which is why slang is reporting an error. I assume some other tool is allowing this anyway as an extension. I can consider allowing this in slang for compatibility purposes.

For reference, here is Table 30-1:

Operator	Description
~	bitwise negation
&	reduction AND
&	bitwise AND
|	reduction OR
|	bitwise OR
^	reduction XOR
^	bitwise XOR
~&	reduction NAND
^~ ~^	bitwise XNOR
~|	reduction NOR
==	logical equality
^~ ~^	reduction XNOR
!=	logical inequality
{}	concatenation
&&	logical AND
{ {} }	replication
||	logical OR
?:	conditional
!	logical NOT

[vowstar]

Thank you for your detailed and informative response! I appreciate your willingness to consider extending slang's capabilities to include features like $countdrivers and state-dependent path conditions using the triple-equals operator. Indeed, my experiences are based on using the VCS simulator, which seems to allow these extensions.

[vowstar]

Thanks!