[pooma-dev] Compile Time Problems and Pooma 2

[Scott Haney]

On Tuesday, May 29, 2001, at 05:24 PM, Dave Nystrom wrote:

> Scott Haney writes:
>> As a general principle, we can agree that circular dependencies are 
>> bad.
>> Field is using auxiliary templates that need information from Field.
>> This problem can be worked around nicely in non-templated C++ code, but
>> it is difficult to work through with templates. However, maybe, by
>> re-factoring, this can be fixed. In particular, AltView1 doesn't use
>> that much of Field. I will give this a shot.
>
> Well, good luck.  Sounds like I've opened up a real can of worms.  Do 
> you
> have any comments on the rest of my original email from Sunday or my 
> response
> to Stephen.  I'm particularly interested in whether you think there is 
> much
> to be gained in terms of reducing the amount of code generated and 
> improving
> compile times by revisiting the logical design.
>
> --
> Dave Nystrom			email: wdn at lanl.gov
> LANL X-3			phone: 505-667-7913	fax: 505-665-3046

Hi Dave,

I have no doubt that we can improve compile times. However, I'm not sure 
what to make of your numbers. They imply that something strange is 
happening on the SGI, but that's not really our target platform, so I 
don't believe that we should spend much time looking into this right 
now. Our priorities are, as I understand it, to (1) provide core 
capabilities in order to allow you guys to meet your October deadline 
and (2) to optimize performance and scalability. I'd put compile time 
performance in (2), but the contract clearly implies we should focus on 
run time first. That said, it is worth a little more time to investigate 
this View preinstantiation issue because it can elucidate some design 
principles that can be used to reduce the number of template 
instantiations as we go forward. In the long term, I believe that we may 
need to provide a tool of some sort to support pre-instantiation, but 
that is not a job for now.

Scott