[Bug c++/105838] g++ 12.1.0 runs out of memory or time when building const std::vector of std::strings

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105838

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2022-06-13

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed with -O1.  At -O0 I see

> /usr/bin/time /space/rguenther/install/gcc-12.1/bin/g++ -S t.C
13.44user 0.34system 0:15.71elapsed 87%CPU (0avgtext+0avgdata
1139560maxresident)k
65584inputs+23864outputs (77major+275588minor)pagefaults 0swaps

with -O1 it uses >20GB of memory in cleanup_all_empty_eh.  It might be
the order of optimizing this is exposing some quadratic amount of
edge redirection, I have not yet analyzed this in detail but trimming down
the testcase should help here.  There isn't much allocation done here
besides the edge redirection SSA update stuff for PHIs.