[Bug middle-end/60418] [4.9 Regression] 435.gromacs in SPEC CPU 2006 is miscompiled

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60418

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to H.J. Lu from comment #1)
> Do we need to verify that basic block DEST has a single predecessor?

No, that's not necessary.  In fact that disables all pre-header
removal (because the loop header always has the loop entry and at least
one latch)