[Bug tree-optimization/128082] Compile-time hog in fre1 at -O2 on a loop header with many latch edges (switch dispatch loop)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128082

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |compile-time-hog
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2026-10-23
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot 
gnu.org

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hmm, simple latches should turn this into a loop nest and --param
rpo-vn-max-loop-depth (7) should limit iteration complexity (which otherwise
scales with loop depth).

I will have a look as to why (if?) that is not working.

-O1 turns off iteration (it's supposed to be usable for "weird" auto-generated
code).