Performance test of short-circuiting AliasSeq

[FeepingCreature]

On Tuesday, 2 June 2020 at 09:19:57 UTC, Stefan Koch wrote:
> Vtune doesn't do intrusive profiling as far as I know.
> Therefore it's measurements _can_ miss functions which are 
> called often,
> but are very short running.
> A profile  obtained by periodic sampling is has the potential 
> of misrepresenting the situation.
>

I don't see how this can be.

A sampling profiler doesn't rely on any sort of program 
breakpointing. Be the function long-running or short-running, if 
it's active 1% of the time it will (on net) show up on 1% of 
sampled backtraces, and so on. To my best understanding, the only 
way a function can fail to be visible if it's (depending on 
sample density, more or less) irrelevant to the total runtime. 
(Or it's invisibly inlined.)