Correcting Athlon (SSE3 and Fx) support for configure/build of gcc

[Uros Bizjak]

Hello!

> Presently, support for the k8/Athlon64/Opteron SSE3 enhanced AMD processors and the Athlon-fx is in the compiler. This is wonderful, however, when trying to use them during compile
> of gcc itself, they aren't recognized as valid options by the configure and build. The present configure scripts do not recognize them as options, although they are listed in
> http://gcc.gnu.org/onlinedocs/gcc/i386-and-x86_002d64-Options.html

> It appears that when the amdfam10 models were added to configure, that sse3 support was overlooked. Regarding the fx model, it was added to the messages regarding supported
> processors, however when the script is supposed to be setting up the flags, it is not being set up.

> Regarding stability outlooks, all instruction set options used by the SSE3 family processors are used in the amdfam10 and barcelona models. The amdfam10 and barcelona models are
> fully supported by the configure scripts already, therefor any stability issues found in the SSE3 family would be present in the already-fully-supported-by-configure amdfam10 cpus.

> Having this applied allows building with the *-sse3 or athlon-fx cpu types listed in documentation. The athlon64-sse3 models of note are the Athlon 64X2 5000+ Black Edition and Athlon
> 64X2 6400+ Black Edition which were top sellers for several months; and they support SSE3 but not SSE4 or ABM. Due to lack of SSE4 or ABM, they should not use the amdfam10 cpu > type during configure.

> For reference, relevant bug: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42786

> * 2010-01-19 Felyza Wishbringer <fwishbringer@gmail.com>
> - fix support for configure with athlon-fx cpu type (42786)
> - add support for configure with *-sse3 cpu types (42786)

This ChangeLog is too short, please see many examples in ChangeLog
files in the source tree.

Offline, I have received the approval from build maintainer (Paolo).
I'll fix the ChangeLog and commit the patch to 4.5 for you. It will be
backported to 4.4 and 4.3 branches after 4.4.3 is released.

Thanks,
Uros.