[Bug tree-optimization/99165] New: [11 Regression] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[Bug tree-optimization/99165] New: [11 Regression] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

            Bug ID: 99165
           Summary: [11 Regression] ICE in verify_dominators, at
                    dominance.c:1184 since r11-7205-g95d94b52ea847833
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: rguenth at gcc dot gnu.org
  Target Milestone: ---

The following fails:

$ cat new.C
struct A {
  A() : i() {}
  int i;
} *ap2 = new A[3];

$ g++ new.C --param=max-stores-to-track=2 -O2 -fnon-call-exceptions
struct A {
  A() : i() {}
  int i;
} *ap2 = new A[3];
new.C: In function ‘(static initializers for new.C)’:
new.C:4:18: error: dominator of 10 status unknown
    4 | } *ap2 = new A[3];
      |                  ^
new.C:4:18: error: dominator of 11 status unknown
new.C:4:18: error: dominator of 12 should be 11, not 5
during GIMPLE pass: store-merging
new.C:4:18: internal compiler error: in verify_dominators, at dominance.c:1184
0x76f16a verify_dominators(cdi_direction)
        /home/marxin/Programming/gcc/gcc/dominance.c:1184
0xd3ab17 checking_verify_dominators
        /home/marxin/Programming/gcc/gcc/dominance.h:76
0xd3ab17 calculate_dominance_info(cdi_direction)
        /home/marxin/Programming/gcc/gcc/dominance.c:746
0x1393f5d verify_ssa(bool, bool)
        /home/marxin/Programming/gcc/gcc/tree-ssa.c:1108
0x10851c8 execute_function_todo
        /home/marxin/Programming/gcc/gcc/passes.c:2049
0x10857ec do_per_function
        /home/marxin/Programming/gcc/gcc/passes.c:1687
0x10857ec execute_todo
        /home/marxin/Programming/gcc/gcc/passes.c:2096
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug tree-optimization/99165] [11 Regression] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.0
      Known to work|                            |10.2.0
   Last reconfirmed|                            |2021-02-19
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
      Known to fail|                            |11.0
           Priority|P3                          |P1

[Bug tree-optimization/99165] [11 Regression] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Is that really a regression given you need an option that didn't exist before?

[Bug tree-optimization/99165] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11 Regression] ICE in      |ICE in verify_dominators,
                   |verify_dominators, at       |at dominance.c:1184 since
                   |dominance.c:1184 since      |r11-7205-g95d94b52ea847833
                   |r11-7205-g95d94b52ea847833  |

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #1)
> Is that really a regression given you need an option that didn't exist
> before?

No, sorry.

[Bug tree-optimization/99165] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

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

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

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Well, given the new param has a default and thus has an effect even without
being specified and given the param likely exposes a latent issue the
regression is likely with introduction of the pass.

I will have a look.

[Bug tree-optimization/99165] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I think there are two problems, one as that apparently the pass can be tricked
into processing the stores it emitted again and the other, possibly related,
that the dominators are wrong with the non-call-exceptions store merging.
pass_store_merging::execute already uses gsi_next before calling 
process_store / terminate_all_aliasing_chains, so I think it can't happen
without non-call-exceptions store merging, but perhaps we need to update bb
from gsi_stmt (gsi).  No idea how to discover if we'd add a new bb and
gsi_empty_p (gsi) would be true.  Perhaps we need to mark in bb flags whether
it is a bb meant for store merging and not set it on newly created bbs (but let
those have the end processed through gsi_next).

[Bug tree-optimization/99165] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
I'm already testing a patch for the simple error I introduced.

[Bug tree-optimization/99165] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

--- Comment #6 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:8a8eee6bdb906788992622715bf97aff984ac989

commit r11-7317-g8a8eee6bdb906788992622715bf97aff984ac989
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Feb 22 08:36:55 2021 +0100

    tree-optimization/99165 - fix ICE in store-merging w/ non-call EH

    This adds a missing accumulation to ret.

    2021-02-22  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/99165
            * gimple-ssa-store-merging.c (pass_store_merging::process_store):
            Accumulate changed to ret.

            * g++.dg/pr99165.C: New testcase.

[Bug tree-optimization/99165] ICE in verify_dominators, at dominance.c:1184 since r11-7205-g95d94b52ea847833

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99165

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

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

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.