RE: [sv-bc] Mantis 1573

Thanks,

> Port coercion is not applicable when net collapsing occurs 
> since the directions aren't "coerced" -- they become immaterial.
> 
> My understanding is that the port coercion description exists 
> in the LRM as a concession to implementations which may 
> choose to not collapse nets.  The port coercion gives a 
> mechanism to approximate the effect of collapsing.
> 
> Because of that, trying to describe things precisely is very 
> difficult since there are two fundamentally different 
> approaches at work.  Realistically we probably don't need to 
> worry too much since customers are quite effective at making 
> sure that the
> *reality* of a port-coercing approach is pretty close to that 
> of collapsing.
> 
> Back to you specific question -- I am just a bit 
> uncomfortable with your wording since someone might read that 
> as meaning that port directions are *respected* with 
> collapsing.  That really isn't true, but neither is the 
> "coercing" model.  The reality is that when ports are 
> collapsed they collapse to a single "wire" and directions 
> become irrelevant.  So I'd probably be a bit more comfortable 
> in saying that if collapsing occurs, port coercion becomes 
> irrelevant as port directions are ignored throughout the 
> collapsed net.

OK. Others agree?

> BTW, while I do know of implementations that do port coercion 
> and others that do collapsing, I don't know of any that don't 
> do either.  There are good reasons for that -- the real 
> behavior becomes pretty strange and not acceptable to 
> customers.  So I wouldn't belabor the "if neither occurs" 
> case since I really don't think you could ever get a useful 
> implementation if you didn't do either.

According to that, you could never get the warning? But I have seen it.

I also know of a tool which has a compiler directive to turn off port
coercion.

Shalom
---------------------------------------------------------------------
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.