Checking if an Integer is an Exact Binary Power

[Marco Leise via Digitalmars-d]

Am Mon, 25 Apr 2016 17:04:43 +0000
schrieb tsbockman <thomas.bockman at gmail.com>:

> On Monday, 25 April 2016 at 16:48:14 UTC, Lass Safin wrote:
> > Example;
> >
> > import core.bitop;
> > import core.cpuid;
> >
> > int count;
> > if(hasPopcnt)
> >     count = _popcnt; // Uses x86-instruction "popcnt".
> > else
> >     count = popcnt; // Phobos's software implementation.
> >
> > // Do stuff with count  
> 
> That is not right (since 2.069, I think?). Adding that check just 
> makes things slower and more complicated:
> 
> core.bitop.popcnt() itself already checks hasPopcnt, and forwards 
> to the intrinsic if it is available.

Can we just use __traits(hasTargetFeature, "popcnt") already
and get rid of _popcnt?

-- 
Marco