[Bug tree-optimization/108828] New: ivopts silencing gcc.dg/Wuse-after-free-2.c:115

[Bug tree-optimization/108828] New: ivopts silencing gcc.dg/Wuse-after-free-2.c:115

[hp at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108828

            Bug ID: 108828
           Summary: ivopts silencing gcc.dg/Wuse-after-free-2.c:115
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hp at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: cris-elf

Source from r13-5978-g4f5a1198065d.
Running the test-suite for a cross to cris-elf on x86_64-pc-linux-gnu shows
among other differences for cris-elf:

Running /x/gcc/gcc/testsuite/gcc.dg/dg.exp ...
FAIL: gcc.dg/Wuse-after-free-2.c  (test for warnings, line 115)
FAIL: gcc.dg/Wuse-after-free-2.c  (test for warnings, line 116)

Diffing tree dumps from -fdump-tree-all-all shows a suspicious difference in
the "180t.ivopts" dump compared to that of the native run; for cris-elf, IIUC
some temporary object is introduced that causes dissociation with the
pointer...or something.  Anyway, "-fno-ivopts" makes the warning appear for
cris-elf.

I don't see this test-suite-failure for recent reports to gcc-testresults@ for
other targets (pru-unknown-elf, arm-unknown-linux-gnueabi,
powerpc64le-unknown-linux-gnu, aarch64-suse-linux-gnu, s390x-ibm-linux-gnu,
powerpc-ibm-aix7.2.5.0).
The test has failed since it's introduction; it's not a regression.

[Bug tree-optimization/108828] ivopts silencing gcc.dg/Wuse-after-free-2.c:115

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108828

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic, testsuite-fail

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I would suggest to add -fno-ivopts to the testcases.  The diagnostic runs very
late and is prone to IL changes as all static analysis we do on optimized code.

[Bug tree-optimization/108828] ivopts silencing gcc.dg/Wuse-after-free-2.c:115

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108828

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Hans-Peter Nilsson <hp@gcc.gnu.org>:

https://gcc.gnu.org/g:8c58f4b798177d419c5af37b7e23c490849f2d45

commit r13-6364-g8c58f4b798177d419c5af37b7e23c490849f2d45
Author: Hans-Peter Nilsson <hp@axis.com>
Date:   Fri Feb 24 17:22:02 2023 +0100

    testsuite: Add -fno-ivopts to gcc.dg/Wuse-after-free-2.c, PR108828

    For cris-elf before this patch, ever since it was added,
    this test gets:

    Running /x/gcc/testsuite/gcc.dg/dg.exp ...
    FAIL: gcc.dg/Wuse-after-free-2.c  (test for warnings, line 115)
    FAIL: gcc.dg/Wuse-after-free-2.c  (test for warnings, line 116)

    and comparing tree dumps with a native x86_64-pc-linux-gnu
    run shows a suspicious difference in the "180t.ivopts" dump.
    Indeed -fno-ivopts makes the warning appear for cris-elf
    too.  It was suggested to simply add -fno-ivopts to the
    test-flags, like before -fno-tree-loop-distribute-patterns
    was added; thus.

            PR tree-optimization/108828
            * gcc.dg/Wuse-after-free-2.c: Add -fno-ivopts.

[Bug tree-optimization/108828] ivopts silencing gcc.dg/Wuse-after-free-2.c:115

[hp at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108828

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-02-28
             Status|UNCONFIRMED                 |SUSPENDED

--- Comment #3 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
Suspending, pending actual fix for tracking through ivopts.