[Bug tree-optimization/101151] New: ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed

[Bug tree-optimization/101151] New: ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed

[zhendong.su at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

            Bug ID: 101151
           Summary: ICE at -O1 and above on x86_64-linux-gnu: verify_ssa
                    failed
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhendong.su at inf dot ethz.ch
  Target Milestone: ---

It appears to be a recent regression.

[511] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/suz-local/software/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--prefix=/local/suz-local/software/local/gcc-trunk --enable-languages=c,c++
--disable-werror --enable-multilib --with-system-zlib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20210621 (experimental) [master revision
edf0c3ffb59:30584177106:12bdd39755a25d237b7776153cbe03e171396fc5] (GCC)
[512] %
[512] % gcctk -O0 small.c; ./a.out
[513] %
[513] % gcctk -O1 small.c
small.c: In function ‘main’:
small.c:2:5: error: stmt with wrong VUSE
    2 | int main() {
      |     ^~~~
# VUSE <.MEM_8(D)>
b.0_1 = b;
expected .MEM_6
during GIMPLE pass: sink
small.c:2:5: internal compiler error: verify_ssa failed
0x1038aeb verify_ssa(bool, bool)
        ../../gcc-trunk/gcc/tree-ssa.c:1214
0xcb0437 execute_function_todo
        ../../gcc-trunk/gcc/passes.c:2049
0xcb11e2 execute_todo
        ../../gcc-trunk/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.
[514] %
[514] % cat small.c
int a, *b = &a, c, d;
int main() {
  *b;
  if (a) {
  L1:
    a = 0;
  L2:
    if (d) {
      while (b)
        ;
      goto L1;
    }
  }
  if (c)
    goto L2;
  return 0;
}

[Bug tree-optimization/101151] [11/12 Regression] ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed since r11-3705-gdae673abd37d4004

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.2
     Ever confirmed|0                           |1
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-06-22
            Summary|ICE at -O1 and above on     |[11/12 Regression] ICE at
                   |x86_64-linux-gnu:           |-O1 and above on
                   |verify_ssa failed           |x86_64-linux-gnu:
                   |                            |verify_ssa failed since
                   |                            |r11-3705-gdae673abd37d4004

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r11-3705-gdae673abd37d4004.

[Bug tree-optimization/101151] [11/12 Regression] ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed since r11-3705-gdae673abd37d4004

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
            Version|unknown                     |11.1.1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Meh.

[Bug tree-optimization/101151] [11/12 Regression] ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed since r11-3705-gdae673abd37d4004

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
The

                      /* If the blocks are possibly within the same irreducible
                         cycle the above check breaks down.  */

check is incomplete.  Testing fix.

[Bug tree-optimization/101151] [11/12 Regression] ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed since r11-3705-gdae673abd37d4004

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

--- Comment #4 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:a2ef8395fa970498985764514044e5fd00f7d5c0

commit r12-1718-ga2ef8395fa970498985764514044e5fd00f7d5c0
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Jun 22 10:14:02 2021 +0200

    tree-optimization/101151 - fix irreducible region check for sinking

    The check whether two blocks are in the same irreducible region
    and thus post-dominance checks being unreliable was incomplete
    since an irreducible region can contain reducible sub-regions but
    if one block is in the irreducible part and one not the check
    still doesn't work as expected.

    2021-06-22  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/101151
            * tree-ssa-sink.c (statement_sink_location): Expand irreducible
            region check.

            * gcc.dg/torture/pr101151.c: New testcase.

[Bug tree-optimization/101151] [11 Regression] ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed since r11-3705-gdae673abd37d4004

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11/12 Regression] ICE at   |[11 Regression] ICE at -O1
                   |-O1 and above on            |and above on
                   |x86_64-linux-gnu:           |x86_64-linux-gnu:
                   |verify_ssa failed since     |verify_ssa failed since
                   |r11-3705-gdae673abd37d4004  |r11-3705-gdae673abd37d4004
      Known to work|                            |12.0

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk sofar.

[Bug tree-optimization/101151] [11 Regression] ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed since r11-3705-gdae673abd37d4004

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:8dc3768ffb4debc559e428fd508a4e8c59586c00

commit r11-8654-g8dc3768ffb4debc559e428fd508a4e8c59586c00
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Jun 22 10:14:02 2021 +0200

    tree-optimization/101151 - fix irreducible region check for sinking

    The check whether two blocks are in the same irreducible region
    and thus post-dominance checks being unreliable was incomplete
    since an irreducible region can contain reducible sub-regions but
    if one block is in the irreducible part and one not the check
    still doesn't work as expected.

    2021-06-22  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/101151
            * tree-ssa-sink.c (statement_sink_location): Expand irreducible
            region check.

            * gcc.dg/torture/pr101151.c: New testcase.

    (cherry picked from commit a2ef8395fa970498985764514044e5fd00f7d5c0)

[Bug tree-optimization/101151] [11 Regression] ICE at -O1 and above on x86_64-linux-gnu: verify_ssa failed since r11-3705-gdae673abd37d4004

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101151

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

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

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