new proposal to vector intrinsics in Fortran

[Jerry DeLisle]

Sa Liu wrote:
> Hi,
> 
>> Please don't start pinging to ask for answers less than 24 hours after
>> your initial mail! We (maintainers) read and will reply, but you can't
>> possibly expect an answer in a matter of hours.
>>
>> Taking a bit of time to think it through, in fact, is radically
>> different than replying at the very minute you receive the email. I
>> can't speak for other but I have read your mail thoroughly and have
>> started a draft reply, but will send it after giving it some more
>> thoughts (and after looking up a few things in the code). Probably
>> other maintainers are doing the same. In any case, we're all
>> volunteers with day jobs that do not involve GCC/gfortran, and will
>> have different time constraints than yours: e.g., I will probably
>> reply this week-end, when I get time to do it.
> 
> Very sorry for the impatient ping... I was just afraid that this thread 
> would die again like it's predecessor. If this is not the case, please 
> just take your time.
> 
>> We certainly will make a decision on that. However, the time window
>> for that decision will be more than a few days, you have to realize
>> that. (Also, talking about timescales, I hope that you're aware of GCC
>> development rules and of the fact that this new feature, if included,
>> will only be incorporated in the forthcoming 4.4 development branch).
> 
> I'm aware of that. I don't expect to get this upstreamed overnight. For me 
> it's just important to know whether this is reasonable for gfortran and 
> could be included in a certain furture release, so that it's worth to put 
> more efforts into it.
> 
>> In the meantime, here are a few points that I wanted to raise:
>>
>>   -- I think that vector types are a interesting feature because of
>> the recent evolution of processors, but I'd like to understand better
>> what currently exist in that domain: you already told us (with links
>> to appropriate documentation) what the IBM compiler does, but what
>> about other compilers?
>>
>>   -- What is the community demand for it? Who would use it? (Who
>> already uses the IBM extensions?) It needs to be worth incorporating
>> and maintaining.
>>
>>   -- [**] If there is community demand for this, it will end up in a
>> later Fortran standard: have there already been such proposals or
>> plans? We want to make sure that, if we create a functionality, it is
>> as close as possible to a future standard proposal.
> 
>> For the last two points, I think a nice thing would be to ask on
>> comp.lang.fortran to gather opinions. Some very knowledgeable and
>> influential people hang there, so I think that's a necessary step. How
>> does that sound to you?
> 
> Thanks for pointing these out. I rarely thought of including it to Fortran 
> standard. I got the request from customer of IBM CELL/B.E. blade and the 
> ESSL library, who want to benefit from the SIMD instructions on CELL 
> architecture. And I think it could also be interesting for the other 
> platforms supporting vector computing. I have seen similar requests 
> appeared on comp.lang.fortran, and I'll try to ask for more opinions 
> there.
> 
> Thank you again for your reply!
> 
> Sa
> 
> 
I just wanted to confirm that like FX, I am reviewing the proposal as well.  In 
between a bunch of stuff, so I will feed back what I think maybe this weekend.

Jerry