Does dmd have SSE intrinsics?

[Daniel Keep]

Robert Jacques wrote:
> On Tue, 22 Sep 2009 07:09:09 -0400, bearophile
> <bearophileHUGS at lycos.com> wrote:
>> Robert Jacques:
> [snip]
>>> Also, another issue for game/graphic/robotic programmers is the
>>> ability to
>>> return fixed length arrays from functions. Though struct wrappers
>>> mitigates this.
>>
>> Why doesn't D allow to return fixed-sized arrays from functions? It's
>> a basic feature that I can find useful in many situations, it looks
>> more useful than most of the last features implemented in D2.
>>
>> Bye,
>> bearophile
> 
> Well, fixed length arrays are an implicit/explicit pointer to some
> (stack/heap) allocated memory. So returning a fixed length array usually
> means returning a pointer to now invalid stack memory. Allowing
> fixed-length arrays to be returned by value would be nice, but basically
> means the compiler is wrapping the array in a struct, which is easy
> enough to do yourself. Using wrappers also avoids the breaking the
> logical semantics of arrays (i.e. pass by reference).

The problem is that currently you have a class of types which can be
passed as arguments but cannot be returned.

For example, Tango's Variant has this horrible hack where the ACTUAL
definition of Variant.get is:

    returnT!(S) get(S)();

where you have:

    template returnT(T)
    {
        static if( isStaticArrayType!(T) )
            alias typeof(T.dup) returnT;
        else
            alias T returnT;
    }

I can't recall the number of times this stupid hole in the language has
bitten me.  As for safety concerns, it's really no different to allowing
people to return delegates.  Not a very good reason, but I *REALLY* hate
having to special-case static arrays.

P.S. And another thing while I'm at it: why can't we declare void
variables?  This is another thing that really complicates generic code.