[fpc-devel] Forwarded message about FPC status

Michael Van Canneyt michael at freepascal.org
Tue Dec 25 12:40:29 CET 2012



On Tue, 25 Dec 2012, Sven Barth wrote:

> On 25.12.2012 12:13, Martin Schreiber wrote:
>> On Tuesday 25 December 2012 11:20:02 Michael Van Canneyt wrote:
>>> 
>>> Everybody is aware of the speed difference between Delphi and FPC.
>>> 
>>> The compiling itself (parsing/producing assembler code) is not slow.
>>> 
>>> >From what I remember, the problems you (and everyone else) experience
>>> 
>>> with smartlinking and so on are largely due to the GNU linker being
>>> slow and memory hungry.
>>> 
>> AFAIK there are significant differences in parsing and code producing too.
>> Last time I checked on Windows with the internal FPC linker Delphi 7 
>> compiled
>> and linked about 10 times as fast as FPC.
>
> AFAIK Delphi's command line compiler does not allow you to skip the 
> assembling and linking phase, so the fairest comparison would be to compare 
> the compilation of a single unit as there the linking phase is skipped. If 
> Delphi is still better there then there are two possibilities: improve the 
> internal assembler or the parser/code generator. Please keep in mind though 
> that FPC's code generator is written in such a way that the backend can be 
> switched rather easily. As we learned with the developer's blog entries about 
> Delphi XE2 this wasn't the case with Delphi XE and older. So it could be that 
> you can never reach the speed of Delphi 7's compiler as FPC is more portable.

Which is why I wrote that limiting the number of CPUs/Platforms would 
be the obvious optimisation, but one which is incompatible with FPC's goals.

Michael.



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