Efficient way to pass struct as parameter

[H. S. Teoh]

On Wed, Jan 03, 2018 at 07:02:28AM +0000, Tim Hsu via Digitalmars-d-learn wrote:
> On Tuesday, 2 January 2018 at 22:49:20 UTC, Adam D. Ruppe wrote:
> > On Tuesday, 2 January 2018 at 22:17:14 UTC, Johan Engelen wrote:
> > > Pass the Vector3f by value.
> > 
> > This is very frequently the correct answer to these questions! Never
> > assume ref is faster if speed matters - it may not be.
> 
> However speed really matters for me.

That's why you need to use a profiler to find out where the hotspots
are. It may not be where you think it is.


> I am writing a path tracing program.  Ray will be constructed million
> of times during computation.  And will be passed to functions to test
> intersection billion of times.  After Reading comments here, it seems
> ray will be passed by value to the intersection testing function. I am
> not sure if ray is small enough to be passed by value. It needs some
> experiment.

With modern CPUs with advanced caching, it may not always be obvious
whether passing by value or passing by reference is better.  Always use
a profiler to be sure.


T

-- 
If blunt statements had a point, they wouldn't be blunt...