[jheriko]

its interesting to see a break down of this - especially using modern compilers on the intel platform.

did you try the intel compiler? for raw low level optimisation it sometimes massively out performs the ms, gcc or clang versions...

i'd imagine these problems are worse on ARM chips, and dynamic dispatch is even less effective there - certainly on PPC architectures I've seen much worse performance than on similarly powered Intels in precisely this situation. the caches are less and slower...

i'm not 100% but i think i've seen virtual calls 'devirtualised' by the MS compiler a couple of years ago... I might be thinking of something else though, it was a while back now. I was unpicking some CRTP mess in something that /was not performance critical in anyway/...

[pmjordan]

You may be thinking of this: IIRC the standard recommends that compilers omit dynamic dispatch when the dynamic type is known at compile time - this essentially boils down to the case where a virtual method call follows creation of the object with 'new' or as an automatic variable. In my experience, this is commonly implemented correctly in compilers.

The other case where the dynamic type is known is in the constructor itself of course.

[eliasmacpherson]

thanks again for your comment the other day about memcpy(), I am after finding a deep and rich seam of optimisation out of it!