[sv-bc] RE: [sv-ec] !, && and || operators allowed for virtual interface or event or chandle variables

Those operators are currently not legal any for data type that accepts
null as a value. See table 11-1 in draft 4. For example, you must write
your first expression as

initial begin
         if ((vi3!=null) || (vi1!=null))

There has been some discussion about the meaning of

if (vi3)

which the LRM says is equivalent to

if (vi3 !=0)

and would clearly be illegal, but most implementations already accept
that.

Dave



> -----Original Message-----
> From: owner-sv-ec@server.eda.org [mailto:owner-sv-ec@server.eda.org]
On
> Behalf Of Moumita
> Sent: Monday, March 10, 2008 12:51 AM
> To: sv-bc; sv-ec
> Subject: [sv-ec] !, && and || operators allowed for virtual interface
or
> event or chandle variables
> 
> Hi,
> 
> !, && and || operators are allowed for class handle variable as null
can
> be
> assigned to any class handle variable.
> 
> And null can also be assigned to any virtual interface or event or
chandle
> variable
> So  !, && and || operators should be allowed for these variables too.
> So if we have a testcase -
>     I1 i1();
>     virtual i1 vi1 = null;
>     virtual i1 vi3 = null;
>     chandle d, a   ;
>     event e1, e2 = null;
> 
>     initial begin
>         if (vi3 || vi1)  //|| operaor is used with virtual interface
> variable
> 	begin
> 	end
>         if( d && a)  //&& operator is used with chandle variable
> 	begin
>         end
>         if(!e1) // ! operator is used with event varaible
>         begin
>         end
>     end
> endmodule
> 
> interface I1;
> endinterface
> 
> 
> Is there any issue for these cases?
> 
> Thanks and regards,
> Moumita
> 
> 
> 
> 
> 
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