[Bug tree-optimization/125793] phi_opt should factor out calls

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125793

--- Comment #2 from Drea Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> I'll mention tail merging here (which can only merge full equal blocks, not
> tails of blocks).

I looked into that, there is a bug about changing tail merging over to use ICF
hashing and equals (PR 70032). Though there has been no progress on that one
for 10 years.