[Bug tree-optimization/107153] New: [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[Bug tree-optimization/107153] New: [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107153

            Bug ID: 107153
           Summary: [13 Regression] ICE in check_loop_closed_ssa_def, at
                    tree-ssa-loop-manip.cc:645
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc 13.0.0 20220925 snapshot (g:77bbf69d2981dafc2ef3e59bfbefb645d88bab9d) ICEs
when compiling the following testcase w/ -O1 -floop-parallelize-all
-ftree-parallelize-loops=2 -fno-tree-dominator-opts:

void
foo (int x, int y)
{
  int i;

  for (i = 0; i < 2; i++)
    {
    }

  while (x)
    if (!y)
      while (y)
        ++y;
}

% gcc-13.0.0 -O1 -floop-parallelize-all -ftree-parallelize-loops=2
-fno-tree-dominator-opts -c rssq9kpi.c
during GIMPLE pass: ompexpssa
rssq9kpi.c: In function 'foo':
rssq9kpi.c:2:1: internal compiler error: in check_loop_closed_ssa_def, at
tree-ssa-loop-manip.cc:645
    2 | foo (int x, int y)
      | ^~~
0x77e395 check_loop_closed_ssa_def
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/tree-ssa-loop-manip.cc:645
0x106f1a4 check_loop_closed_ssa_bb
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/tree-ssa-loop-manip.cc:659
0x1070566 verify_loop_closed_ssa(bool, loop*)
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/tree-ssa-loop-manip.cc:695
0x1070566 verify_loop_closed_ssa(bool, loop*)
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/tree-ssa-loop-manip.cc:679
0xdfcf64 execute_function_todo
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/passes.cc:2109
0xdfd33e execute_todo
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/passes.cc:2145

[Bug tree-optimization/107153] [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107153

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2022-10-04
             Status|UNCONFIRMED                 |NEW
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org

[Bug tree-optimization/107153] [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107153

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.0
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Likely my (virtual LC update-ssa) fault.

[Bug tree-optimization/107153] [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107153

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
OK, so the main issue is that when we parallelize a loop without stores we
insert stores and thus would require a loop PHI for the virtual operand plus
LC SSA updates.

We eventually end up in gen_parallel_loop at

      /* We assume that the loop usually iterates a lot.  */
      loop_version (loop, many_iterations_cond, NULL,
                    profile_probability::likely (),
                    profile_probability::unlikely (),
                    profile_probability::likely (),
                    profile_probability::unlikely (), true);
      update_ssa (TODO_update_ssa_no_phi);

which performs the update but doesn't insert PHIs - the above assumed
that we'd have no SSA update pending before the call to loop_version.

separate_decls_in_region is what creates the stores (with no virtual
operands, thus triggering renaming and the need for a LC PHI).

I'm going to work around.

[Bug tree-optimization/107153] [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107153

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

https://gcc.gnu.org/g:89228e3985c5cdf6be58a3b5b1afcad91e9e3422

commit r13-3161-g89228e3985c5cdf6be58a3b5b1afcad91e9e3422
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Oct 7 10:28:56 2022 +0200

    tree-optimization/107153 - autopar SSA update issue

    autopar performs insertion of stores, eventually requiring a
    virtual loop PHI and assorted LC PHI adjustments which we intend
    to do once after the pass finishes.  But we also perform intermediate
    update_ssa after loop duplication which can lose this fact.  The
    following forces renaming of the virtual operand before the final
    SSA update to fix that.  It also removes the explicit update_ssa
    call from the gimple_duplicate_sese_tail utility as has been done
    for all other such utilities and instead performs the SSA update
    from autopar.

            PR tree-optimization/107153
            * tree-cfg.cc (gimple_duplicate_sese_tail): Do not update
            SSA form here.
            * tree-parloops.cc (gen_parallel_loop): Update SSA form
            after to-exit-first transform, no PHI insertion is necessary.
            (pass_parallelize_loops::execute): Force re-write of the
            virtual operand SSA web.

            * gcc.dg/autopar/pr107153.c: New testcase.

[Bug tree-optimization/107153] [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107153

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.

[Bug tree-optimization/107153] [13 Regression] ICE in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:645

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107153

--- Comment #5 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:a99f511c57b5b02edfd5969148c580b4a8737ee8

commit r13-3191-ga99f511c57b5b02edfd5969148c580b4a8737ee8
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Mon Oct 10 12:04:56 2022 +0200

    Require fgraphite effective target for pr107153.c test [PR107153]

    The test uses -floop-parallelize-all which emits a sorry when graphite
    isn't configured in.

    2022-10-10  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/107153
            * gcc.dg/autopar/pr107153.c: Require fgraphite effective target.