[Bug middle-end/110590] New: Failing CFG consistency testcases

[Bug middle-end/110590] New: Failing CFG consistency testcases

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110590

            Bug ID: 110590
           Summary: Failing CFG consistency testcases
           Product: gcc
           Version: 13.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hubicka at gcc dot gnu.org
  Target Milestone: ---

there are 3 testcases that checks for Invalid sum but fogets to enable
blocks-details which fails after this is fixed:

  gcc.dg/tree-ssa/loop-ch-profile-1.c
     here the problem is that loop header dulication introduces loop invariant
conditoinal that is later
     updated by tree-ssa-dom but dom does not take care of updating profile.
     Since loop-ch knows when it duplicates loop invariant, we may be able to
get this right.

     The test is still useful since it tests that right after ch profile is
consistent.
  gcc.dg/tree-prof/update-cunroll-2.c
     This is about profile updating code in duplicate_loop_body_to_header_edge
being wrong when optimized
     out exit is not last in the loop.  In that case the probability of later
exits needs to be accounted in.
     I will think about making this better - in general this does not seem to
have easy solution, but for
     special case of chained tests we can definitely account for the later
exits.
  gcc.dg/tree-ssa/update-unroll-1.c
     This fails after aprefetch invoked unrolling.  I did not look into details
yet.

[Bug middle-end/110590] Failing CFG consistency testcases

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110590

--- Comment #1 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Forgot about 
  gcc.dg/tree-prof/update-unroll-2.c

[Bug middle-end/110590] Failing CFG consistency testcases

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110590

--- Comment #2 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
... and testsuite/gcc.dg/unroll-7.c

[Bug middle-end/110590] Failing CFG consistency testcases

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110590

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jan Hubicka <hubicka@gcc.gnu.org>:

https://gcc.gnu.org/g:15bbf1826a01f5beb2d7c0f74d6270bbc94ece91

commit r14-2396-g15bbf1826a01f5beb2d7c0f74d6270bbc94ece91
Author: Jan Hubicka <jh@suse.cz>
Date:   Sat Jul 8 17:38:09 2023 +0200

    Fix tree-ssa/update-cunroll.c

    In this testcase the profile is misupdated before loop has two exits.
    The first exit is one eliminated by complete unrolling while second exit
remains.
    We remove first exit but forget about fact that the source BB of other exit
will
    then have higher frequency making other exit more likely.

    This patch fixes that in duplicate_loop_body_to_header_edge.
    While looking into resulting profiles I also noticed that in some cases
    scale_loop_profile may drop probabilities to 0 incorrectly either when
    trying to update exit from nested loop (which has similar problem) or when
the profile
    was inconsistent as described in coment bellow.

    gcc/ChangeLog:

            PR middle-end/110590
            * cfgloopmanip.cc (scale_loop_profile): Avoid scaling exits within
            inner loops and be more careful about inconsistent profiles.
            (duplicate_loop_body_to_header_edge): Fix profile update when
eliminated
            exit is followed by other exit.

    gcc/testsuite/ChangeLog:

            PR middle-end/110590
            * gcc.dg/tree-prof/update-cunroll-2.c: Remove xfail.
            * gcc.dg/tree-ssa/update-cunroll.c: Likewise.