[Bug tree-optimization/50905] Gcc4.6.x's -ftree-parallelize-loops is effective only when using "-O2/-O3 -ffast-math"

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50905

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-10-28 19:45:18 UTC ---
>Am I right?
Yes but the reason comes down to fp math is not associative which means it is
impossible to do reductions with fp math unless you have -ffast-math (or really
-fassociative-math) turned on.