RE: [sv-ac] Enhancements submitted

Hi Dave,

Unfortunately we cannot. Consider the example from #1646

property weak_until ( property p , property q ) ;
	generate if ( $isboolean ( q ) )
		! q [ *1 : $ ] |-> p ;
	else
		q or ( p and ( 1 ' b1 j=> weak_until ( p , q ) ) ) ;
	endgenerate
endproperty

If we query the type of q, we'll get 'property'. We need to know whether
this is a combinatorial property, i.e., actually a Boolean value. If it
is - then a more efficient implementation is possible, as shown in this
example.

I.e., I need to know not the actual type of an argument, but the ability
to reduce the actual argument type to a simpler type: sequence to
Boolean and property to sequence or to Boolean.

These query functions I suggest, are useful in properties only in
conjunction with the generate constructs, therefore I had to introduce
these two enhancements simultaneously.

Thanks,
Dmitry

P.S. The example I talked was missing from the initial version of the
file attached to #1646, but now I've uploaded the right version.

-----Original Message-----
From: owner-sv-ac@server.eda.org [mailto:owner-sv-ac@server.eda.org] On
Behalf Of Rich, Dave
Sent: Tuesday, October 24, 2006 7:02 PM
To: Brad Pierce; sv-ac@server.eda-stds.org
Subject: RE: [sv-ac] Enhancements submitted

SV already allows expressions like

(type(expr) == real)

These are evaluated at elaboration time and do not evaluate their
operands other than to determine their type.

Couldn't we do

(type(expr) == sequence)



> -----Original Message-----
> From: owner-sv-ac@server.eda.org [mailto:owner-sv-ac@server.eda.org]
On
> Behalf Of Brad Pierce
> Sent: Tuesday, October 24, 2006 9:26 AM
> To: sv-ac@server.eda-stds.org
> Subject: Re: [sv-ac] Enhacements submitted
> 
> Dmitry,
> 
> Regarding the type query functions of 1647, a few questions --
> 
>    1)  "is a Boolean expression, i.e., it may be used as a condition
of
> a procedural if statement"  But any packed vector could be used as
such
> a condition.
> 
>    2)  Why can't these also be called on a data_type?
> 
>    3)  Why only these few?  Why not, for example, $issigned, as
> discussed in
> 
>           http://www.eda-stds.org/sv-bc/hm/4866.html
> 
>        or $isstring, $isreal, etc.
> 
>    4)  What are the return types?
> 
>    5)  Do these functions evaluate their arguments?
> 
>    6)  Can they be called in a constant expression?
> 
> -- Brad
> 
> 
> ________________________________
> 
> From: owner-sv-ac@eda.org [mailto:owner-sv-ac@eda.org] On Behalf Of
> Korchemny, Dmitry
> Sent: Tuesday, October 24, 2006 8:14 AM
> To: sv-ac@eda-stds.org
> Subject: [sv-ac] Enhacements submitted
> 
> 
> 
> Hi all,
> 
> 
> 
> I submitted three detailed proposals following my presentations:
> 
> 
> 
> 1646 - Generate constructs within properties and sequences
> 
> 1647 - Type query functions
> 
> 1648 - Default reset for assertions
> 
> 
> 
> Thanks,
> 
> Dmitry
>