[fpc-devel] Pointer cache for fast class/pointer access.

[Jonas Maebe]

On 22 Jan 2012, at 11:04, Sven Barth wrote:

> Ah... inside the compiler's sources. I thought you meant "the compiler inserts calls to prefetch in specific situations". ^^

It can also do that, if you compile it with -dprefetchnext (at least if that still works, it's been a long time since I implemented and tried that). In that case, it will look for constructs like this:

while assigned(hp) do
  begin
    ...
    hp:=hp^.next;
  end;

and it will insert prefetch instructions like this:

while assigned(hp) do
  begin
    prefetch(hp^.next^);
    ...
    hp:=hp^.next;
  end;

I don't remember exactly, but I think it will also consider class fields as implicit pointers and insert the transformation there. At least for the compiler cycle this optimization does not change anything though.


Jonas