[PATCH] Support powerpc64le-linux platform

[Torbjorn Granlund]

"Ulrich Weigand" <uweigand at de.ibm.com> writes:

  this patch updates GMP to support the little-endian PowerPC64
  platform (powerpc64le-linux).  This requires two changes:
  
  - Update configfsf.guess/sub to current upstream versions.
  
I think Niels volunteered to do that...

  - Change mpn/powerpc64/elf.m4 to generate appropriate assembler
    code for the new ELFv2 ABI.  The relevant change here is that
    we no longer require function descriptors; instead, functions
    that use the TOC register need to provide a pair of global
    and local entry points.  For more details, see the GCC patch
    messages here:
    http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01144.html
    http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01141.html
  
  Tested using "make check" on powerpc64le-linux; in addition,
  we've been using this patch for a while when building GMP
  to use with the native GCC on the platform.
  
  Also, built and tested with no regressions on powerpc64-linux.
  
Good!

Comments:

Testing cpp symbols for ABI version makes me a bit nervous.  Such things
can easily get out-of-synch.  It might be more resilient to check a
generated object.

Is the setting of of a TOC pointer unconditionally really needed
(presumably for a call from another shlib including the main program)
even for leaf functions which also don't use the TOC?

Is there a way we could test powerpc64le-linux or the new abi?  We try
to have (automated) tests for every ABI which we claim to be supporting.

-- 
Torbjörn