64-bit configure hell

[Joe Buck]

On Wed, Nov 24, 2004 at 07:20:46PM -0500, Kaveh R. Ghazi wrote:
>  > 	    Some solutions that I have found so far:
>  > 1) Disable 64-bit multilib when configuring on G4s.
> 
> Even though it's a 64-bit OS, some Solaris2.7 installations only
> support 32-bit binaries, probably on older processors just like your
> situation Stan.
> 
> The official solution there is to simply disable multilib during
> configure just as David suggests.  See:
> http://gcc.gnu.org/install/specific.html#sparc-sun-solaris2*

How about a blacklist approach?  If we have a specific OS or processor
where we know that the answers we would otherwise get from configure about
64-bit support are wrong, it could just be flagged based on the
target triplet generated by config.guess.  In some cases config.guess
might need to be refined a bit to detect processor variants if this
isn't done already.

Certainly we can document it in install/specific.html, but it would
be nicer if ./configure, make bootstrap just works (or at least stops
with a readable error message).