[Bug c/110777] New: ice: SSA corruption

[Bug c/110777] New: ice: SSA corruption

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

            Bug ID: 110777
           Summary: ice: SSA corruption
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

This C code 

int *findOrAddBackgroundInPalette_palette_pnm;
static void findOrAddBackgroundInPalette(unsigned *paletteSizeP,
                                    int *backgroundIndexP) {
  if (*paletteSizeP) {
    *backgroundIndexP = (*paletteSizeP)++;
    pm_message();
  }
  pm_message(findOrAddBackgroundInPalette_palette_pnm[*backgroundIndexP]);
}
void computeColorMap(int *backgroundIndexP) {
  unsigned paletteSize;
  findOrAddBackgroundInPalette(&paletteSize, backgroundIndexP);
}
int main() {
  unsigned backgroundIndex;
  _setjmp();
  computeColorMap(&backgroundIndex);
}

with recent gcc trunk, does this:

$ ~/gcc/results/bin/gcc -c -O3 -w ~/cvise/bug944.c

Unable to coalesce ssa_names 27 and 31 which are marked as MUST COALESCE.
paletteSize_27(ab) and  paletteSize_31(ab)
during RTL pass: expand
/home/dcb38/cvise/bug944.c: In function ‘main’:
/home/dcb38/cvise/bug944.c:14:5: internal compiler error: SSA corruption
   14 | int main() {
      |     ^~~~
0xf95b19 fail_abnormal_edge_coalesce(int, int)
        ../../trunk.year/gcc/tree-ssa-coalesce.cc:1003
0xf95b19 coalesce_partitions(_var_map*, ssa_conflicts*, coalesce_list*,
_IO_FILE*)
        ../../trunk.year/gcc/tree-ssa-coalesce.cc:1425


The bug first seems to occur sometime between g:b2cfe5233e682fc0
and g:f32518726ee8e836, a range of 30 commits.

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|ice: SSA corruption         |[14 Regression] ice: SSA
                   |                            |corruption
           Keywords|                            |ice-on-valid-code
   Target Milestone|---                         |14.0
          Component|c                           |tree-optimization
            Version|unknown                     |14.0

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Is this reduced from some other code? Because the testcase here depends on an
uninitialized variable.

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

--- Comment #2 from David Binderman <dcb314 at hotmail dot com> ---
Created attachment 55615
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55615&action=edit
C source code

Original pre-reduction source code.

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

--- Comment #3 from David Binderman <dcb314 at hotmail dot com> ---
Attempting bisection. Trying g:85a4e4f93ff251f2

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

--- Comment #4 from David Binderman <dcb314 at hotmail dot com> ---
Current range seems to be g:23ad5ed7432bea7c to g:85a4e4f93ff251f2.

Trying g:b6b72562d116bd0a

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

David Binderman <dcb314 at hotmail dot com> changed:

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

--- Comment #5 from David Binderman <dcb314 at hotmail dot com> ---
$ git bisect good c5bd0e5870aed178
d0de3bf9175877d6c51c94fe04662c6e031876e1 is the first bad commit
commit d0de3bf9175877d6c51c94fe04662c6e031876e1
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Jul 17 12:15:29 2023 +0200

    tree-optimization/110204 - second level redundancy and simplification

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-07-22

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

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

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

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
I will have a look.

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

--- Comment #8 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:50b5feaa94c26d01fed13f1119f025ae2bc75d2b

commit r14-2738-g50b5feaa94c26d01fed13f1119f025ae2bc75d2b
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Jul 24 08:55:11 2023 +0200

    tree-optimization/110777 - abnormals and recent PRE optimization

    The following avoids propagating abnormals with the recent tweak
    to look through PRE introduced copies between equal values.

            PR tree-optimization/110777
            * tree-ssa-sccvn.cc (eliminate_dom_walker::eliminate_avail):
            Avoid propagating abnormals.

            * gcc.dg/pr110777.c: New testcase.

[Bug tree-optimization/110777] [14 Regression] ice: SSA corruption

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110777

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

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

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.  thanks for reporting