Blog post: PGO: Optimizing D's virtual calls

[Marco Leise via Digitalmars-d-announce]

Am Fri, 15 Apr 2016 09:04:21 +0000
schrieb Johan Engelen <j at j.nl>:

> On Wednesday, 13 April 2016 at 11:34:26 UTC, Johan Engelen wrote:
> > Hi all,
> >   I've written an article about how I implemented 
> > profile-guided optimization (PGO) of virtual calls to direct 
> > calls (a micro-micro-optimization, expected performance gain of 
> > just a few percent if any!).  
> 
> I've updated the article with performance measurements of just 
> the D code of LDC: the improvement with PGO is about 7% !

Compilers are full of logic that makes some code 0.5% faster.
The sum of all these little bits is what makes up an
optimizing compiler and if today you still find an optimization
that's worth 1 or 2% you have a jackpot!

7% is quite a bit more than any other option like -cpu=native
could achieve. If feasible I'd enjoy if ldc2 shipped with a
pgo configuration option. If you use the compiler in a lot of
edit/compile cycles it will pay off.

-- 
Marco