[Bug rtl-optimization/119681] extraneous move instructions when unrolling core_list_reverse () with -O3 -funroll-all-loops; not copying the return block

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119681

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
>(Note that the GIMPLE unroller already does this, but it doesn't handle 
>uncountable loops.)

Actually the gimple unroller does NOT duplicate exit blocks at all. Rather it
is how out of ssa works when it deals with phi nodes here and splits the live
range which allows the rtl to work better.