Any usable SIMD implementation?

[Walter Bright via Digitalmars-d]

On 4/7/2016 3:52 AM, Kai Nacke wrote:
> On Thursday, 7 April 2016 at 03:27:31 UTC, Walter Bright wrote:
>> Then,
>>
>>     void app(int simd)() { ... my fabulous app ... }
>>
>>     int main() {
>>       auto fpu = core.cpuid.getfpu();
>>       switch (fpu) {
>>         case SIMD: app!(SIMD)(); break;
>>         case SIMD4: app!(SIMD4)(); break;
>>         default: error("unsupported FPU"); exit(1);
>>       }
>>     }
>>
>
> glibc has a special mechanism for resolving the called function during loading.
> See the section on the GNU Indirect Function Mechanism here:
> https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/W51a7ffcf4dfd_4b40_9d82_446ebc23c550/page/Optimized%20Libraries
>
>
> Would be awesome to have something similar in druntime/Phobos.

We already have core.cupid, which covers most of what that article talks about. 
The indirect function thing appears to be a way to selectively load from various 
dlls. But that can be done anyway with core.cpuid and dynamic dll loading, so 
I'm not sure what advantage it brings.