[Bug middle-end/38474] compile time explosion in dataflow_set_preserve_mem_locs at -O3

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38474

--- Comment #104 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #103)
> (In reply to Andrew Pinski from comment #102)
> > At -O2 -g add_stack_var_conflict looks to be high up. Which might mean this
> > introduced recently by me.
> 
> Can you split out a PR tracking this?

Yes but it looks like it is not related to my fix for add_stack_var_conflict
since it happened from a compiler from October.