Subject: Re: [sv-cc] open issue: exported function = virtual function?
From: Francoise Martinolle (fm@cadence.com)
Date: Thu Mar 27 2003 - 07:50:33 PST
I agree with John.
Remember that the cname is optional, and most likely will not be provided
since the SV function name is a legal C function name.
If provided it is just a C aliased name for the SV function.
If we start by allowing same cname for multiple export functions, then we 
reintroduce
a complex binding mechanism which was not the original goal of DPI.
The original goal was simple default binding between SV and C to avoid 
complex binding and registration of C functions.
Francoise
        '
At 05:09 PM 3/26/2003 -0500, Stickley, John wrote:
>Andrzej,
>
>I'm inclined to only allow cnames to map to 1 exported
>function, although I understand your desire to support
>a virtual function of sorts.
>
>If we allow this I have concerns that the SV compiler
>generated code wrappers for the exported functions will
>have to decide which SV code to call based on the
>module scope setting. This may add extra overhead.
>
>Since SV does not support a similar "virtual function"
>feature - at least in module scopes, I don't think
>we should introduce one.
>
>-- johnS
>
>Andrzej Litwiniuk wrote:
>>  > Glad to see we converged so quickly on this one.
>>  > [...]
>>  > Doug
>>Wait a minute! We converged on the restriction only, that it is a must.
>>The issue whether to allow more than one function SV source code definition
>>per cname seems to be open. Poll?
>>Andrzej
>>
>>  > > :-)
>>  > >
>>  > > Doug,
>>  > >
>>  > > we added exactly the same restriction already to the LRM
>>  > > (version 0.8) ...
>>  > > Funny how we all think alike.
>>  > > At minimum, that restriction was required purely for
>>  > > technical reasons: if
>>  > > two different SV functions in same scope mapped to the same
>>  > > cname, how would
>>  > > the compiler know which one to call when a call to that cname
>>  > > was made in
>>  > > that scope ?
>>  > >
>>  > > Joao
>>  > > ==============================================================
>>  > > ================
>>  > > Joao Geada, PhD             Principal Engineer
>>  > > Verif Tech Group
>>  > > Synopsys, Inc
>>  > > TEL: (508) 263-8083
>>  > > 344 Simarano Drive, Suite 300,
>>  > > FAX: (508) 263-8069
>>  > > Marlboro, MA 01752, USA
>>  > > ==============================================================
>>  > > ================
>>  > >
>>  > >
>>  > > -----Original Message-----
>>  > > From: owner-sv-cc@eda.org [mailto:owner-sv-cc@eda.org]On Behalf Of
>>  > > Warmke, Doug
>>  > > Sent: Wednesday, March 26, 2003 3:08 PM
>>  > > To: 'Andrzej Litwiniuk'; sv-cc@eda.org
>>  > > Subject: RE: [sv-cc] open issue: exported function = virtual function?
>>  > >
>>  > > ...
>>  > > > Susprisingly (for me, Joao wasn't surprised at all!) the restriction
>>  > > > "one signature per cname" does =not= mean "one source code
>>  > > per cname".
>>  > > > Actually, it doesn't matter what was the source code, as long
>>  > > > as the signature
>>  > > > matches. SV implementation will have to identify the right
>>  > > > code anyway.
>>  > >
>>  > > DOUG: This is fine.  However, there should be the restriction that
>>  > > only all export function cname's used in a given declarative scope
>>  > > should be unique.  This "virtual function" mechanism would only
>>  > > work when selecting between function variants in different
>>  > > instantiated declarative scopes.
>>  > >
>>  > > ...
>>  > >
>>  >
>
>
>--
>
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