On Thu, 2 Aug 2012, Richard Guenther wrote:

> On Wed, Aug 1, 2012 at 9:21 PM, Marc Glisse <marc.glisse@inria.fr> wrote:
>> Hello,
>>
>> an opinion on this?
>>
>> (I just noticed: I'll update the list in the comment visible at the top of
>> the patch if this gets in).
>
> It looks ok to me but I am no floating-point expert.  Can you add a testcase?
>
> Ok with that change.

Here again with a testcase. The -O is not necessary for the optimization 
to happen, but it seemed wrong to me not to include it. I wondered about 
adding an explicit -ftrapping-math, for documentation purposes.

I am redoing the bootstrap+regtest, then I'll commit if I don't hear 
protests about the testcase.

gcc/ChangeLog
2012-06-15  Marc Glisse  <marc.glisse@inria.fr>

 	PR tree-optimization/53805
 	* fold-const.c (invert_tree_comparison): Do invert ORDERED_EXPR and
 	UNORDERED_EXPR for floating point.

gcc/testsuite/ChangeLog
2012-06-15  Marc Glisse  <marc.glisse@inria.fr>

 	PR tree-optimization/53805
 	* gcc.dg/fold-notunord.c: New testcase.

-- 
Marc Glisse