https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114010
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- The first example (of assembly here) in comment #0 is extra moves due to the RA not handling subreg that decent for the load/store lane. There are other bug reports dealing with that. Why the SSA_NAMES being monotonically help is just by an accident really. Also: > This mostly affects all the bitmaps that use SSA_NAME_VERSION as a key. Most use sparse bitmaps there so it is not a big deal. I think this should be split up in a few different bug reports really. One for each case where better optimizations happen. Also: >I have seen two similar source files generating the exact same GIMPLE code up >to some optimization pass but then completely diverging due to different >freelists. The only case where I have seen this happen is expand will have different pesdu # really. Yes I noticed this effect while I did r14-569-g21e2ef2dc25de3 really.
