[Bug tree-optimization/106521] New: ICE at -O1 with "-floop-unroll-and-jam --param unroll-jam-min-percent=0": verify_ssa failed

[Bug tree-optimization/106521] New: ICE at -O1 with "-floop-unroll-and-jam --param unroll-jam-min-percent=0": verify_ssa failed

[zhendong.su at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106521

            Bug ID: 106521
           Summary: ICE at -O1 with "-floop-unroll-and-jam --param
                    unroll-jam-min-percent=0": 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 (and possibly related to PR106249).

Compiler Explorer: https://godbolt.org/z/Tanf9axav


[545] % 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/13.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib
--with-system-zlib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 13.0.0 20220803 (experimental) [master r13-1950-g9bb19e143cf] (GCC) 
[546] % 
[546] % gcctk -O1 -floop-unroll-and-jam --param unroll-jam-min-percent=0
small.c
small.c: In function ‘main’:
small.c:4:5: error: definition in block 30 does not dominate use in block 33
    4 | int main() {
      |     ^~~~
for SSA_NAME: b_lsm.15_82 in statement:
b_lsm.15_23 = PHI <b_lsm.15_8(22), b_lsm.15_82(33)>
PHI argument
b_lsm.15_82
for PHI node
b_lsm.15_23 = PHI <b_lsm.15_8(22), b_lsm.15_82(33)>
during GIMPLE pass: unrolljam
small.c:4:5: internal compiler error: verify_ssa failed
0x11356ef verify_ssa(bool, bool)
        ../../gcc-trunk/gcc/tree-ssa.cc:1211
0x105fb5b rewrite_into_loop_closed_ssa_1
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:576
0x105fb5b rewrite_into_loop_closed_ssa(bitmap_head*, unsigned int)
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:626
0x1c94c2d tree_loop_unroll_and_jam
        ../../gcc-trunk/gcc/gimple-loop-jam.cc:612
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
[547] % 
[547] % cat small.c
short a, b, e;
volatile long c;
long d;
int main() {
  for (; d; d++) {
    long g = a = 1;
    for (; a; a++) {
      g++;
      c;
    }
    g && (b = e);
  }
  return 0;
}

[Bug tree-optimization/106521] [13 Regression] ICE at -O1 with "-floop-unroll-and-jam --param unroll-jam-min-percent=0": verify_ssa failed since r13-1450-gd2a898666609452e

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106521

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-08-04
            Version|unknown                     |13.0
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
            Summary|ICE at -O1 with             |[13 Regression] ICE at -O1
                   |"-floop-unroll-and-jam      |with "-floop-unroll-and-jam
                   |--param                     |--param
                   |unroll-jam-min-percent=0":  |unroll-jam-min-percent=0":
                   |verify_ssa failed           |verify_ssa failed since
                   |                            |r13-1450-gd2a898666609452e
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Target Milestone|---                         |13.0

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r13-1450-gd2a898666609452e.

[Bug tree-optimization/106521] [13 Regression] ICE at -O1 with "-floop-unroll-and-jam --param unroll-jam-min-percent=0": verify_ssa failed since r13-1450-gd2a898666609452e

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106521

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

[Bug tree-optimization/106521] [13 Regression] ICE at -O1 with "-floop-unroll-and-jam --param unroll-jam-min-percent=0": verify_ssa failed since r13-1450-gd2a898666609452e

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106521

--- 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:d8552eaddc40b72461158e56b5db8709f2eb21ed

commit r13-1961-gd8552eaddc40b72461158e56b5db8709f2eb21ed
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Aug 4 11:55:15 2022 +0200

    tree-optimization/106521 - unroll-and-jam LC SSA rewrite

    The LC SSA rewrite performs SSA verification at start but the VN
    run performed on the unrolled-and-jammed body can leave us with
    invalid SSA form until CFG cleanup is run.  So make sure we do that
    before rewriting into LC SSA.

            PR tree-optimization/106521
            * gimple-loop-jam.cc (tree_loop_unroll_and_jam): Perform
            CFG cleanup manually before rewriting into LC SSA.

            * gcc.dg/torture/pr106521.c: New testcase.

[Bug tree-optimization/106521] [13 Regression] ICE at -O1 with "-floop-unroll-and-jam --param unroll-jam-min-percent=0": verify_ssa failed since r13-1450-gd2a898666609452e

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106521

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

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

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