[Bug rtl-optimization/80693] [6/7/8 Regression] wrong code with -O -fno-tree-coalesce-vars

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80693

--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> ---
(In reply to Zdenek Sojka from comment #0)
> Also, the costs dump in the first replacement looks wrong:
> original costs 0 + 4 + 4 = 0

This is correct: 0 means undefined.  You usually get it from a
parallel, like here.