gcc-4.5-RH in F14

[Dave Airlie]

On Thu, 2010-07-08 at 09:18 +0200, Jakub Jelinek wrote:
> Hi!
> 
> F14 now has gcc-4.5-RH compiler instead of 4.4-RH.
> For the changes (especially user visible ones), see
> http://gcc.gnu.org/gcc-4.5/changes.html
> (though the list contains even many features that have been
> backported to 4.4-RH.  I had to backport even over 100 of changes
> that were backported to 4.4-RH from trunk already, but aren't on
> 4.5 branch).  Unless using decimal float, the compiler should be ABI
> compatible with 4.4-RH, including the libraries (which ought to be backwards
> compatible).
> 
> If you experience any internal compiler errors or other compiler bugs,
> please file them into bugzilla.
> 
> Please don't rely on LTO in 4.5, it is not mature enough (especially -fwhopr
> is completely unusable, -flto only barely so), things will get better
> in GCC 4.6.
> 

Just saw this on lkml? are kernel builds going to be broken?


On Thu, Jul 8, 2010 at 4:33 PM, Rafael J. Wysocki <rjw at sisk.pl> wrote:
>
> Unresolved regressions
> ----------------------
>
> Bug-Entry       : http://bugzilla.kernel.org/show_bug.cgi?id=16353
> Subject         : 2.6.35 regression
> Submitter       : Zeev Tarantov <zeev.tarantov at gmail.com>
> Date            : 2010-07-05 13:04 (4 days old)
> Message-ID      : <loom.20100705T144459-919 at post.gmane.org>
> References      :
http://marc.info/?l=linux-kernel&m=127836002702522&w=2

This is a gcc-4.5 issue. Whether it's also something that we should
change in the kernel is unclear, but at least as of now, the rule is
that you cannot compile the kernel with gcc-4.5. No idea whether the
compiler is just entirely broken, or whether it's just that it
triggers something iffy by being overly clever.

Dave.