0 is not a power of 2

[Martin Nowak via Digitalmars-d]

On Tuesday, 19 May 2015 at 07:56:27 UTC, Atila Neves wrote:
> Aren't predictable branches cheap on current architectures?

Yes they are, and it seems one would rarely if ever call isPowOf2 
with 0 in std.allocator. A good thing to do, is to use a good 
hardware event profiler like perf, and record the branch misses. 
Perf is also the right tool to compare the branchless version (I 
doubt it's significantly better, especially since the felt of the 
0 branch is just a constant).