[pacman-dev] makepkg.conf: problematic assumption for ppc
kth5 at archlinuxppc.org
Wed Dec 6 08:15:57 EST 2006
the autotool stuff for pacman-lib writes a makepkg.conf with the
following C/XXFLAGS when configured on ppc:
CFLAGS="-mcpu=750 -O2 -pipe"
CXXFLAGS="-mcpu=750 -O2 -pipe"
This is problematic! The past has shown us on archppc that -mcpu=750
might cause problems on G4 AND earlier variants of the PowerPC such as
the 604 (pre-G3). Instead we started to use:
export CFLAGS="-mtune=powerpc -O2 -pipe -mpowerpc-gfxopt -fPIC"
export CXXFLAGS="-mtune=powerpc -O2 -pipe -mpowerpc-gfxopt -fPIC"
of which "-mtune=powerpc" is the one which can be generalized, as
opposed to "-mpowerpc-gfxopt" which will break compatibility to POWER
which is the way I decided to go with archppc. -mtune is a relaxed
optimization as you can see. It has proven to produce stable code on all
PowerPCs we've seen so far.
Also, I'd like to suggest to add "-fPIC" as a ppc default as well.
Relocation does not work the way it does on x86 PHP 5.1+ being the most
prominent representative for the problem. Every single library it links
against must be built with -fPIC in order to load extensions in php.ini.
This is only one example.
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