Comment 6 for bug 7655

On Tue, Aug 31, 2004, David I. Lehn wrote:

> > libmpeg2.so.0 has a TEXTREL entry. This means that it contains non-PIC code
> > and can't be prelinked against.
> >
> > Policy requires that shared libraries are compiled with -fPIC. (Unless
> > there's a really really good excuse, of course.)
>
> -fPIC is not used for performance reasons.

   Well, if the library is not PIC, it's not a shared library since the
text segment cannot be shared. Concurrent processes will each have to
load a separate instance of the library.

> On older machines it can
> make the difference between being able to decode a dvd or not.

   What would be the specs of such machines? Most critical routines
in libmpeg2 have MMX equivalents, and I don't know of any non-MMX x86
machine that can decode a DVD.

> faster machines it probably doesn't matter as much. For one reason or
> another it seems the only remaining architectures that can deal without
> -fPIC are i?86 and k?. Is there anyway around the prelinking issue that
> would allow non-PIC code to be used?

   No.

> It would be unfortunate to have to cripple a library that is so well
> optimized.

   Blame the x86 architecture for having so few registers. The static
version of the library will work at full speed, though.

Sam.
--
Sam Hocevar <email address hidden> <http://sam.zoy.org/>