SIMD support...

[Don]

On 07.01.2012 04:18, Andrei Alexandrescu wrote:
> On 1/6/12 5:52 PM, Walter Bright wrote:
>> Support the 10 vector types as basic types, support them with the
>> arithmetic infix operators, and use intrinsics for the rest of the
>> operations. I believe this scheme:
>>
>> 1. will look better in code, and will be easier to use
>> 2. will allow for better error detection and more comprehensible error
>> messages when things are misused
>> 3. will generate better code
>> 4. shouldn't be hard to implement, as I already did most of the work
>> when I did the SIMD support for float and double.
>
> I think it would be great to try avoiding the barbarism of adding 10
> built-in types and a bunch of built-ins.
>
> Historically, D has erred heavily on the side of building in the
> compiler. Consider the the complex numbers affair, in tow with crackpot
> science arguments on why they're a must. It's great that embarrassment
> is behind us.


 > Also consider how the hard-coding of associative arrays in
> an awkward interface inside the runtime has stifled efficient
> implementations, progress, and innovation in that area. Still a lot of
> work needed there, too, to essentially undo a bad decision.

Sorry Andrei, I have to disagree with that in the strongest possible 
terms. I would have mentioned AAs as a very strong argument in the 
opposite direction!

Moving AAs from a built-in to a library type has been an unmitigated 
disaster from the implementation side. And it has so far brought us 
*nothing* in return. Not "hardly anything", but *NOTHING*. I don't even 
have any idea of what good could possibly come from it. Note that you 
CANNOT have multiple implementations on a given platform, or you'll get 
linker errors! So I think there is more pain to come from it.
It seems to have been motivated by religious reasons and nothing more.
Why should anyone believe the same argument again?