[Bug tree-optimization/46785] Doesn't vectorize reduction x += y*y

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46785

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-12-03 
15:39:49 UTC ---
Btw, I wonder why we bother to check the defs at all and not just do

     def1 && flow_bb_inside_loop_p (loop, gimple_bb (def1))

we should be able to handle all vectorizable reduction operands, and
their vectorizability will be determined anyway.