Checking if an Integer is an Exact Binary Power

[Temtaime via Digitalmars-d]

On Tuesday, 26 April 2016 at 16:53:00 UTC, tsbockman wrote:
> On Tuesday, 26 April 2016 at 14:37:46 UTC, Marco Leise wrote:
>> Can we just use __traits(hasTargetFeature, "popcnt") already
>> and get rid of _popcnt?
>
> No, because DMD does not currently support setting SSE4 as the 
> minimum target. Thus, `__traits(hasTargetFeature, "popcnt")` 
> must always return `false` at compile time.
>
> As for LDC and GDC - both already treat `popcnt()` as an 
> intrinsic, and don't need your proposed change.

It's strange why it emits an branch.

http://goo.gl/jJbSYd
Det version doesn't use cmp and should be fast.