[Bug target/109087] [13 Regression] csmith: end of year runtime bug since r13-4839-geef81eefcdc2a581

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109087

--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I didn't mean for GCC 13, we need to fix the actual backend bug regardless and
so a DSE improvement can't be considered a fix... ;)
Just the DSE thing happens very often with -ftrivial-auto-var-init=.
I wonder if even after your improvement we don't keep .DEFERRED_INIT for unused
vars for the case when the DSE walk will run into the vdef/vuse limits (I
assume it doesn't do unbounded walk).  Perhaps some special handling of
.DEFERRED_INITs for vars which have solely those statements and clobbers and
nothing else?