[Nix-dev] libgmp impurity

[Peter Simons]

Hi,

the gmp library performs rather sophisticated compiler-flag guessing in
its configure script. When run on my system, for instance, it configures
itself as follows:

  using ABI="32"
        CC="gcc"
        CFLAGS="-m32 -O2 -pedantic -fomit-frame-pointer -mtune=athlon -march=athlon"
        CPPFLAGS=""
        MPN_PATH=" x86/k7/mmx x86/k7 x86 generic"

Now, the tricky part is "-march=athlon", because this flag might render
the generated binaries unusable on other x86 architectures. It's
probably safe to assume that gmp will use even more aggressive -march
settings when built on more advanced hardware.

Does anyone have a suggestion how to deal with this issue? 

Take care,
Peter