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Re: kde objprelink and new binutils



On Monday 19 November 2001 18:00, Magnus von Koeller wrote:
> On Saturday 20 October 2001 10:54, Allan Sandfeld Jensen wrote:
> > If you have the time and skills it is always a good idea to compile
> > K-packages yourself. It turned out recently that adding
> > architecture specific optimization makes a big performance
> > difference, becouse of the amount of byteoperations. So get the
> > source and compile it with '-march=<myArch>' :-) (I can also
> > recommend -ffast-math and -finline-functions for good standard
> > optimizations that arent included in -O2)
>
> How do I do this? Is doing
>
> # export CXXFLAGS="-O3 -march=i686"
> # export CPPFLAGS="-O3 -march=i686"
> # export CFLAGS="-O3 -march=i686"
> # dpkg-buildpackage
>
> enough?
>
> Is -O3 a good idea? Or should I rather use "-O2 --ffast-math
> -finline-functions"?

Change the debian/rules  file, it might/does set some flags on its own. If 
not using deb packages, you would simple write: 
CFLAGS='-march=i686 -O2' CXXFLAGS='-march=i686 -O2' ./configure

The only importent flag is -march. The others are for "fun" or experiments, 
please try -O3 if you like, but I doubt it makes much of an impact. btw 
-ffast-math is not included i O3, becouse floating point operations might be 
changed in a way that changes the result, but which are still accurate.

regards 
Allan



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