[Bug middle-end/63311] [4.9/5 Regression] -O1 optimization introduces valgrind warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63311

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is probably ifcombine at work and the target splitting the combined
condition back, but the other way around.