Original patch from: gentoo/src/patchsets/glibc/2.9/1130_all_glibc-2.4-undefine-__i686.patch

 -= BEGIN original header =-

 If gcc is configured to generate i686 code or better by default (like 

 when using the --with-arch=pentium3 configure option), then the __i686

 macro will always be defined automatically and thus screw up the

 compilation of some .S files.

 http://bugs.gentoo.org/131108

 http://sourceware.org/ml/libc-alpha/2006-04/msg00090.html

 2006-04-25  Mike Frysinger  <vapier@gentoo.org>

 	* sysdeps/i386/sysdep.h (__i686): Undefine.

 -= END original header =-

 diff -durN glibc-2_9.orig/nptl/sysdeps/pthread/pt-initfini.c glibc-2_9/nptl/sysdeps/pthread/pt-initfini.c

 --- glibc-2_9.orig/nptl/sysdeps/pthread/pt-initfini.c	2007-06-17 20:02:01.000000000 +0200

 +++ glibc-2_9/nptl/sysdeps/pthread/pt-initfini.c	2009-02-02 22:01:09.000000000 +0100

 @@ -45,6 +45,9 @@

  /* Embed an #include to pull in the alignment and .end directives. */

  asm ("\n#include \"defs.h\"");

 +/* Embed an #include to pull in asm settings. */

 +asm ("\n#ifdef __i686__\n#include <sysdep.h>\n#endif");

 +

  /* The initial common code ends here. */

  asm ("\n/*@HEADER_ENDS*/");

 diff -durN glibc-2_9.orig/sysdeps/i386/sysdep.h glibc-2_9/sysdeps/i386/sysdep.h

 --- glibc-2_9.orig/sysdeps/i386/sysdep.h	2006-10-28 08:44:03.000000000 +0200

 +++ glibc-2_9/sysdeps/i386/sysdep.h	2009-02-02 22:01:09.000000000 +0100

 @@ -18,6 +18,14 @@

     Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA

     02111-1307 USA.  */

 +/*

 + * When building for i686 targets or better, gcc automatically defines

 + * '__i686' to '1' for us which causes trouble when using section names

 + * like '__i686.get_pc_thunk.reg'.  Since we check for __i686__ in the

 + * code, killing '__i686' shouldn't be a problem.

 + */

 +#undef __i686

 +

  #include <sysdeps/generic/sysdep.h>

  #ifdef	__ASSEMBLER__