[fpc-devel] Tail recursion optimization

[Daniël Mantione]

Op Tue, 10 Oct 2006, schreef Micha Nelissen:

> Florian Klaempfl wrote:
> > Yesterday, I've implemented tail recursion optimization
> > (http://svn.freepascal.org/svn/fpc/trunk/compiler/opttail.pas resulting
> > in
> > http://www.hu.freepascal.org/fpcircbot/cgipastebin?msgid=158 pp11 is the
> > new
> > compiler, fpc11 the old, both are 2.1.1). It isn't enabled yet because it
> > still
> > needs some fine tuning. The question is however when should it be
> > enabled? With
> > -OoTAILREC? -O3? Something different?
> 
> It doesn't always improve performance ? It takes much more code ?

I don't think so, because for tail recursion optimization you assign the 
parameters to the local variables (should not be larger than pushing 
them) and then jump to the start of the procedure (should not be larger 
than calling).

Daniël