[Bug testsuite/100073] New: [11 regression] test case gcc.dg/pr86058.c fails after r11-

[Bug testsuite/100073] New: [11 regression] test case gcc.dg/pr86058.c fails after r11-

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

            Bug ID: 100073
           Summary: [11 regression] test case gcc.dg/pr86058.c fails after
                    r11-
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
          Assignee: unassigned at gcc dot gnu.org
          Reporter: seurer at gcc dot gnu.org
  Target Milestone: ---

g:8084ab15a3e300e3b2c537e56e0f3a1b00778aec, r11-8161

make  -k check-gcc RUNTESTFLAGS="dg.exp=gcc.dg/pr86058.c"
FAIL: gcc.dg/pr86058.c actual (test for warnings, line 13)
# of expected passes            1
# of unexpected failures        1


spawn /home/seurer/gcc/git/build/gcc-test/gcc/xgcc
-B/home/seurer/gcc/git/build/gcc-test/gcc/
/home/seurer/gcc/git/gcc-test/gcc/testsuite/gcc.dg/pr86058.c
-fdiagnostics-plain-output -O2 -Wuninitialized -Wmaybe-uninitialized -S -o
pr86058.s
XFAIL: gcc.dg/pr86058.c pr????? (test for warnings, line 13)
FAIL: gcc.dg/pr86058.c actual (test for warnings, line 13)


I don't see any excess warnings so maybe it is a missing warning?

[Bug testsuite/100073] [11 regression] test case gcc.dg/pr86058.c fails after r11-8161

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.0
           Keywords|                            |diagnostic

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The testcase seems new - whether a TARGET_MEM_REF appears or not is obviously
dependent on the target.

[Bug testsuite/100073] [11 regression] test case gcc.dg/pr86058.c fails after r11-8161

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-04-14
           Assignee|unassigned at gcc dot gnu.org      |msebor at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1

--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
Looks like powerpc64 doesn't warn for the code, and apparently neither does
aarch64 with -mabi=ilp32, due to what seems like a limitation in the uninit
pass which sees this IL:

  <bb 3> [local count: 105119324]:
  doloop.6_16 = (unsigned int) indx_9(D);
  ivtmp.9_22 = (unsigned long) &MEM <int[10]> [(void *)&arr + -4B];   <<<
&arr[-1]
  _27 = out_11(D) + 18446744073709551612;
  ivtmp.11_26 = (unsigned long) _27;

  <bb 4> [local count: 955630225]:
  # doloop.6_20 = PHI <doloop.6_17(6), doloop.6_16(3)>
  # ivtmp.9_7 = PHI <ivtmp.9_6(6), ivtmp.9_22(3)>         <<< ivtmp.9_22(3)
points to arr[-1]
  # ivtmp.11_24 = PHI <ivtmp.11_25(6), ivtmp.11_26(3)>
  ivtmp.9_6 = ivtmp.9_7 + 4;                              <<< &arr[0]
  _28 = (void *) ivtmp.9_6;
  _1 = MEM[(int *)_28];                                   <<< uninitialized
read, no warning

[Bug testsuite/100073] [11 regression] test case gcc.dg/pr86058.c fails after r11-8161

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

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

https://gcc.gnu.org/g:785209fc464ee3efec2b2a8e8244b7292c251ad8

commit r11-8179-g785209fc464ee3efec2b2a8e8244b7292c251ad8
Author: Martin Sebor <msebor@redhat.com>
Date:   Wed Apr 14 10:43:22 2021 -0600

    PR testsuite/100073 - test case gcc.dg/pr86058.c fails on arm, powerpc64

    gcc/testsuite/ChangeLog:
            * gcc.dg/pr86058.c: Limit to just x86_64.

[Bug tree-optimization/100073] missing warning on an uninitialized array read in a loop

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11 regression] test case   |missing warning on an
                   |gcc.dg/pr86058.c fails      |uninitialized array read in
                   |after r11-8161              |a loop
             Target|powerpc64*-linux-gnu        |arm-eabi,
                   |                            |powerpc64*-linux-gnu
               Host|powerpc64*-linux-gnu        |
              Build|powerpc64*-linux-gnu        |
             Blocks|                            |24639
             Status|ASSIGNED                    |NEW
          Component|testsuite                   |tree-optimization

--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
I have limited the test to just x86_64 for now and repurposed this bug to track
the missing warning on arm, aarch64 (with -mabi=ilp32) and powerpc64.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24639
[Bug 24639] [meta-bug] bug to track all Wuninitialized issues

[Bug tree-optimization/100073] missing warning on an uninitialized array read in a loop

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|msebor at gcc dot gnu.org          |unassigned at gcc dot gnu.org

--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> ---
See also https://gcc.gnu.org/pipermail/gcc-patches/2021-April/568002.html

[Bug tree-optimization/100073] missing warning on an uninitialized array read in a loop

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:4d1fa72894e3fbc5f331d2e8984e990307396124

commit r11-8194-g4d1fa72894e3fbc5f331d2e8984e990307396124
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Apr 15 14:08:03 2021 +0200

    testsuite: enable pr86058.c also on i?86-*-* [PR100073]

    The test also works with -m32 or -mx32 the same as it does for -m64,
    therefore it should be enabled for i?86-*-* x86_64-*-* targets,
    x86_64-*-* alone is never right.

    2021-04-15  Jakub Jelinek  <jakub@redhat.com>

            PR testsuite/100073
            * gcc.dg/pr86058.c: Enable also on i?86-*-*.

[Bug tree-optimization/100073] missing warning on an uninitialized array read in a loop

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.0                        |11.2

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.1 has been released, retargeting bugs to GCC 11.2.

[Bug tree-optimization/100073] missing warning on an uninitialized array read in a loop

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.2                        |11.3

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.2 is being released, retargeting bugs to GCC 11.3

[Bug tree-optimization/100073] missing warning on an uninitialized array read in a loop

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.3                        |11.4

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.3 is being released, retargeting bugs to GCC 11.4.

[Bug tree-optimization/100073] missing warning on an uninitialized array read in a loop

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100073

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.4                        |11.5

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.4 is being released, retargeting bugs to GCC 11.5.