0 is not a power of 2

[deadalnix via Digitalmars-d]

On Tuesday, 19 May 2015 at 20:09:23 UTC, Steven Schveighoffer 
wrote:
> On 5/19/15 4:01 PM, deadalnix wrote:
>> Have you tried things like :
>>
>> (x >> bsr(x)) == 1 ?
>>
>> I have no idea if this is faster or not, but worth trying.
>
> Hm.. I think this would always succeed. Perhaps you mean:
>
> 1 << bsr(x) == x;
>

Both work as long as you use a fully defined instruction, like 
tzcnt.