[ping] Re: RFA: Improve 128-bit long double configure test

[Daniel Jacobowitz <drow at false dot org>]

On Thu, Nov 15, 2007 at 02:27:57PM -0500, Daniel Jacobowitz wrote:
> MontaVista builds both cross compilers (Linux or Windows -> MVL
> target) and native compilers (MVL host) on their Linux-based build
> systems.  We discovered that the two compilers disagreed on the
> size of long double for PowerPC.  Have I mentioned that I think
> making ABI choices based on configure tests is a really lousy idea?
> 
> This is the best I could think of to solve the problem.  Configure
> wants to grep through /usr/include; if we're building with $build
> != $host (and $host = $target is assured by the previous test, above
> the context of the diff), then ask GCC where glibc's headers are.
> 
> What do you think?  Is the approach OK?  How about the shell scripting
> choices?

Ping.  Patch is here:
  http://gcc.gnu.org/ml/gcc-patches/2007-11/msg00861.html

Mark asked whether we could remove the autodetection entirely, or
use it to AC_WARN instead of changing the ABI based on configure
tests.  I have no strong feeling about this, but while the check is
there I would like it to be more reliable.

-- 
Daniel Jacobowitz
CodeSourcery