Re: [sv-ec] Completing my coverage thought...

Arturo Salz wrote:
> Gord,
> 
> I agree that it's best to not consider empty bins and compute coverage
> as:
> 	num_covered_bins / num_non_empty_bins
> While both mechanisms described by you allow coverage to be 100%, this
> one also exhibits the nice property of being 0 when nothing is run. I
> believe
> it is counterintuitive to have non-zero coverage when no bins are
> covered.
> 
> 	Arturo



Arturo,

That's fine with me.  An edge case -- 18.10.1 doesn't define any rules for
results when the number of non-empty bins is 0.  So, should this be
defined to be:
   1) illegal
   2) 100% coverage
   3) 0% coverage

I don't think I would want (1) to be an LRM requirement (an implementation
might warn of course), but for parameterized ignore_bins, etc. the situation
might actually be reasonable.

If the user anticipates the scenario, I think that (2) is the best
choice since otherwise full coverage can't be reached.

Gord.




> 
> 
> -----Original Message-----
> From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of
> Gordon Vreugdenhil
> Sent: Monday, January 09, 2006 12:52 PM
> To: SV_EC List
> Subject: [sv-ec] Completing my coverage thought...
> 
> Just to complete my thought regarding coverage before the
> call was dropped -- my basic question is whether the coverage
> percentage is:
>      num_covered_bins / num_non_empty_bins
> or:
>      (num_covered_bins + num_empty_bins) / (num_non_empty_bins +
> num_empty_bins)
> 
> (i.e. is an empty bin not considered at all or is it
> trivially covered?)
> 
> I think that the former is perferable, but I don't know for sure.
> 
> Gord.

-- 
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Gordon Vreugdenhil                                503-685-0808
Model Technology (Mentor Graphics)                gordonv@model.com