[Gcl-devel] Re: 'base subarchitecture' configuration

[Kevin Ryde]

Camm Maguire <address@hidden> writes:
>
> For the purposes of distributing binary packages, (e.g. in
> Debian), one would like to configure for the lowest practical common
> denominator, e.g. i486 on Intel machines, etc.

Yes (this gets a mention under "Notes for Package Builds" in the manual).

> 1) Is there a pre-prepared way to do this for gmp?

Set --host to the desired target.

> 2) Barring that, what would be recommended lowest common denominators
>    for the 11 supported Debian platforms?  (i.e. i386, m68k, arm,
>    mips(el), s390, alpha, ia64, hppa, sparc, ppc)

DEB_BUILD_GNU_TYPE gives the right thing, eg. the libgmp3 package uses

        ./configure --build=`dpkg-architecture -qDEB_BUILD_GNU_TYPE`

(No real difference between --build and --host for a native compile
like this, nothing sub-model dependent is done based on the build
system type.)

> On Debian systems, one can actually distribute a variety of shared
> libraries and configure the dynamic library loader to automatically and
> transparently use the optimal version for the running cpu.   We may
> consider this in putting together a future gcl_gmp lib to optimize
> performance, but for now we need the common denominators.

If it's too hard to get multiple versions into the archive it'd be
nice if it was easy for a user to make an optimized package for local
use.