[fpc-devel] Forwarded message about FPC statusy

[Yury Sidorov]

From: "Florian Klaempfl" <florian at freepascal.org>

> Am 25.12.2012 13:39, schrieb Yury Sidorov:
>> It is possible to seed-up compilation by allocating memory for 
>> nodes
>> from some zero pre-filled memory pool to avoid costly calls to heap
>> manager and avoid zero filling of small memory chunks. A base class 
>> for
>> various FPC nodes should be modified to handle aloocation from the 
>> pool...
>
> The heap manager itself does already pooling so I don't see much 
> gain in doing so ...

Still zero-filling a million of small memory chunks is very time 
consuming. It is better to pre-zerofill big pool blocks first and then 
assueme that memory already zero fillled in custom object init code.

Although FPC heap manager is good, but custom pool memory allocation 
will be much faster, since it will be very simple:

  Result:=CurPoolPtr;
  Inc(CurPoolPtr, BlockSize);
  if CurPoolPtr > MaxPoolPtr then AllocNewZeroFilledPool();

It is not needed to handle memory releases during object destruction. 
Since all nodes are available during whole compiling phase (parsing, 
code generation, etc) and released only at the end of a phase, it is 
possible just to release whole pool blocks at the end of a phase.

Such pooled base class for compiler nodes should inrease performanse a 
lot.

Yury Sidorov, jura at cp-lab.com