[Bug tree-optimization/49851] IVOPTs makes a mess out of polyhedron air derivx and derivy

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49851

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-07-26 13:59:26 UTC ---
AIR spends 86% of its time in DERIV[XY] (for ICC), 78% of its time there for
GCC.
The performance difference also reproduces when not inlining DERIV[XY] at all
(though it's slightly less of a difference - GCC doesn't care).