Any usable SIMD implementation?

[9il via Digitalmars-d]

On Tuesday, 5 April 2016 at 21:41:46 UTC, Johan Engelen wrote:
> On Tuesday, 5 April 2016 at 21:29:41 UTC, Walter Bright wrote:
>> 
>> I want to make it clear that dmd does not generate AFX 
>> specific code, has no switch to enable AFX code generation and 
>> has no basis for setting predefined version identifiers for it.
>
> How about adding a "__target(...)" compile-time function, that 
> would return false if the compiler doesn't know?
>
> __target("broadwell")  --> true means: target cpu is broadwell, 
> false means compiler doesn't know or target cpu is not 
> broadwell.
>
> Would that work for all?

Yes, something like that is what I am looking for.
Two nitpicks:
1. __target("broadwell") is not well API. Something like that 
would be more efficient:
enum target = __target();
// .. use target
2. Is it possible to reflect additional settings about 
instruction set? Maybe "broadwell,-avx"?