On 23 April 2016 at 15:56, Andrei Alexandrescu via Digitalmars-d <digitalmars-d@puremagic.com> wrote: > On 4/23/16 9:54 AM, Andrei Alexandrescu wrote: >> >> On 4/23/16 9:06 AM, Vladimir Panteleev wrote: >>> >>> On Saturday, 23 April 2016 at 13:04:00 UTC, Nordlöw wrote: >>>> >>>> Wanted: CT-trait and run-time predicate for checking whether its >>>> single integer parameter is an exact power of two. >>> >>> >>> popcnt(x) <= 1 ? >> >> >> Would be interesting to see how it compares to the handwritten version >> on different machines. popcnt has a reputation of being slow in older >> CPUs, in recent ones it has a latency of 3 cycles and a throughput of 1 >> cycle. -- Andrei > > > Oh, and the bummer is that on gdc it's a function call: > https://godbolt.org/g/dEYCcG -- Andrei >
That can easily be changed. ;-)
