RE: [sv-ec] random resizing of associative array

Arturo,
 
OK, I agree that you are proposing that the indices should be set to 0..N
 
Going back to Gord's earlier post, why is this needed if resizing a dynamic array has the same effect?
 
Dave
 


________________________________

From: Arturo Salz [mailto:Arturo.Salz@synopsys.com]
Sent: Wed 5/17/2006 3:55 PM
To: Rich, Dave; Arturo Salz; Ryan, Ray; Vreugdenhil, Gordon
Cc: sv-ec@eda.org
Subject: RE: [sv-ec] random resizing of associative array



Dave,

I didn't imply you said that. I'm sorry if I left that impression.

The index value IS a state variable because it must be a literal
constant. Only the foreach construct allows non-literal indices.

My point is that I did specify how the index value is set: when an
associative array isd resized, the indices become 0..N (N = size-1).
And, it follows from that description that arrays of non integral
indices cannot be resized.

        Arturo

-----Original Message-----
From: Rich, Dave [mailto:Dave_Rich@mentor.com]
Sent: Wednesday, May 17, 2006 3:13 PM
To: Arturo Salz; Ryan, Ray; Vreugdenhil, Gordon
Cc: sv-ec@eda.org
Subject: RE: [sv-ec] random resizing of associative array

Arturo,

I think we are in agreement, at least agree your example should be
legal.

I didn't say that you couldn't use an AA in a constraint; I just said
the index value would be a state variable, i.e. not randomized.

If you were to allow re-sizing an AA, you'd have to specify how the
index value is to be set.

Dave


> -----Original Message-----
> From: Arturo Salz [mailto:Arturo.Salz@synopsys.com]
> Sent: Wednesday, May 17, 2006 3:04 PM
> To: Rich, Dave; Ryan, Ray; Vreugdenhil, Gordon; Arturo Salz
> Cc: sv-ec@eda.org
> Subject: RE: [sv-ec] random resizing of associative array
>
> Dave,
>
> Disallowing associative arrays from participating in constraints as
> random variables is too restrictive. If users do not resize the
> associative array there is no ambiguity. Also, the LRM already states
> that index expressions must be literal constants, so it's not possible
> to randomize the indices. Consider the following:
>
>       rand byte aa[int];
>       rand a, b;
>
>       constraint x { foreach( aa, j ) { aa[j] inside { a, b }; }
>
> That is a perfectly good constraint.
>
> I believe the only erratum needed is to specify what happens when the
> size of the associative array is constrained. My proposal is
> straightforward and I believe allows most useful situations without
> being unduly restrictive.
>
>       Arturo
>
> -----Original Message-----
> From: Rich, Dave [mailto:Dave_Rich@mentor.com]
> Sent: Wednesday, May 17, 2006 2:35 PM
> To: Ryan, Ray; Vreugdenhil, Gordon; Arturo Salz
> Cc: sv-ec@eda.org
> Subject: RE: [sv-ec] random resizing of associative array
>
> I don't think this is the desired behavior, nor does the LRM even
> remotely suggest this.
>
> I would propose that we add an erratum explicitly saying that
> randomize() shall not re-size an associative array and shall consider
> the size and keys as state variables.
>
> Dave
>
>