FW: [sv-bc] 'inside' on real operands

Here's a question for you.

I'm attaching a description of the 'inside' operator.

Thanks,

Shalom


-----Original Message-----
From: Stuart Sutherland [mailto:stuart@sutherland-hdl.com]
Sent: Monday, September 10, 2007 6:48 PM
To: 'Jonathan Bromley'; 'Geoffrey.Coram'; Alsop, Thomas R
Cc: Bresticker, Shalom; 'sv-bc'
Subject: RE: [sv-bc] 'inside' on real operands


Would using reals with the inside operator be useful for Verilog-AMS?
If not, I agree with prohibiting reals as operands of inside.  If the
Verilog-AMS committee sees this as useful, then we should define the
behavior and any caveats.

Stu
~~~~~~~~~~~~~~~~~~~~~~~~~
Stuart Sutherland
Sutherland HDL, Inc.
stuart@sutherland-hdl.com
503-692-0898


> -----Original Message-----
> From: owner-sv-bc@server.eda.org
> [mailto:owner-sv-bc@server.eda.org] On Behalf Of Jonathan Bromley
> Sent: Monday, September 10, 2007 7:04 AM
> To: Geoffrey.Coram; Alsop, Thomas R
> Cc: Bresticker, Shalom; sv-bc
> Subject: RE: [sv-bc] 'inside' on real operands
>
> > A "user beware" note in the LRM might be appropriate, but I agree
> > that users should be able to use inside for reals if they want.
>
> Whilst this makes sense from a language design point of view, I think
> it's very dangerous.  The obvious intuitive interpretation of "inside"
> for reals is "somewhere within this real range".
> When combined with the fact that wildcard comparison makes no sense
> for reals, and the fragility of == on reals, I think the balance
> should be in favour of prohibiting reals as operands of 'inside' if
> the right-hand operand is considered to be a countable set of values. 
> Furthermore, if we preserve the present meaning of 'inside' whereby
> its RHS specifies a set of values, then a real range such as [1.0:2.0]
> makes no sense.
>
> I completely agree with Steven Sharp that the following would be both
> reasonable and (very) useful...
>
>   R inside {[1.0:2.0], [3.0:4.5]}
>
> and I think that's what users would expect to be able to do - but that
> makes a specification of a set with an uncountable number of members;
> and it suggests that putting anything *except* such ranges on the RHS
> of an 'inside' with real LHS would need to be specified to be
> erroneous.
> --
> Jonathan Bromley, Consultant
>
> DOULOS - Developing Design Know-how
> VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
>
> Doulos Ltd. Church Hatch, 22 Market Place, Ringwood, Hampshire, BH24
> 1AW, UK
> Tel: +44 (0)1425 471223                   Email:
> jonathan.bromley@doulos.com
> Fax: +44 (0)1425 471573                           Web:
> http://www.doulos.com
>
> The contents of this message may contain personal views which are not
> the views of Doulos Ltd., unless specifically stated.
>
> --
> This message has been scanned for viruses and dangerous content by
> MailScanner, and is believed to be clean.
>
>
>
>


---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.