Karim BELABAS on Wed, 14 Nov 2001 01:51:25 +0100 (MET)

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Re: library installation/Mac OS X

On Tue, 13 Nov 2001, Ilya Zakharevich wrote:

> On Tue, Nov 13, 2001 at 08:33:21PM +0100, Karim BELABAS wrote:
> > Hum, it looks like the 'dlcompat' library still fails to provide the expected
> > support.  Does it still occur when you add -fPIC to CFLAGS and recompile ??
> > (I think Math::Pari includes it by default ?)
> Math::Pari includes it on the platforms where MakeMaker decides
> it is needed.  In other words: Math::Pari does not do any effort to
> tweak dynaloading: it uses the standard ExtUtuls::MakeMaker-supplied
> recipes.

OK, let's say that MakeMaker would add it by default on most platforms (whose
compiler is gcc), then.

MakeMaker wants to produce a genuine shared library (with -fPIC) where
libpari.so does not want to be position-independant: we don't really care
about not sharing memory between running processes, whereas we do care about
the performance penalty associated with position-independant code.  That's why
-fPIC is omitted by default.  [ A good compromise would be to link the PARI
kernel statically, and make a genuine shared library with the rest, the PIC
penalty would be much smaller, possibly the usually advertised 5% or so. ]

Karim Belabas                    email: Karim.Belabas@math.u-psud.fr
Dep. de Mathematiques, Bat. 425
Universite Paris-Sud             Tel: (00 33) 1 69 15 57 48
F-91405 Orsay (France)           Fax: (00 33) 1 69 15 60 19
PARI/GP Home Page: http://www.parigp-home.de/