Re: [Chicken-users] GCC, dereferencing type-punned pointer...

[felix]

On Sat, 06 Sep 2003 09:01:10 +0200 (CEST), <address@hidden 
Hagen.de> wrote:

> On 05 Sep 2003, Johannes Groedem <address@hidden> wrote:
> > I'm getting hundreds (thousands?) of these warnings from GCC (3.3.2
> > 20030831 (Debian prerelease)):
> >
> > warning: dereferencing type-punned pointer will break
> > strict-aliasing rules
>
> For 3.3.1 too (this started in the 3.3 branch).
>
> > I'm just wondering whether I can safely ignore them,
>
> > From my experience: yes.
> But I typically modify configure as follows:
>
> sed -i -e "s/-fstrict-aliasing/-fno-strict-aliasing/g" configure
>
> -O3 normally implies -fstrict-aliasing, therefore you have to turn
> it off explicitly.
> I don't know whether performance changes ... Does anybody have numbers?

Sorry, no hard numbers yet, but it does give slightly better performance.
Sven, have you had any problems with -fstrict-aliasing? I would be 
interested
how your nallch performs with/without that option.


cheers,
felix