Hi Timo,
There are no changes in the logic, it's just to avoid a crash ("internal compiler error: in vect_transform_stmt, at tree-vect-stmts.c:4887"). It's only in GCC versions 4.6.x.
Incidentally, was it through an oversight, or with a design, that KiConvertToGuiThread (one which is in trap.s, committed in r52509), does not save/restore EBX?