[Bug tree-optimization/114787] [13 Regression] wrong code at -O1 on x86_64-linux-gnu (the generated code hangs)

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114787

--- Comment #19 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:715a1df9082b40cf810283632218258ac9c86773

commit r13-8697-g715a1df9082b40cf810283632218258ac9c86773
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Apr 24 08:42:40 2024 +0200

    tree-optimization/114787 - more careful loop update with CFG cleanup

    When CFG cleanup removes a backedge we have to be more careful with
    loop update.  In particular we need to clear niter info and estimates
    and if we remove the last backedge of a loop we have to also mark
    it for removal to prevent a following basic block merging to associate
    loop info with an unrelated header.

            PR tree-optimization/114787
            * tree-cfg.cc (remove_edge_and_dominated_blocks): When
            removing a loop backedge clear niter info and when removing
            the last backedge of a loop mark that loop for removal.

            * gcc.dg/torture/pr114787.c: New testcase.

    (cherry picked from commit cc48418cfc2e555d837ae9138cbfac23acb3cdf9)