[Bug tree-optimization/118552] New: ICE on valid code at -O3 with "-fno-tree-ch -fno-tree-ccp -fno-tree-fre" on x86_64-linux-gnu: in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:647

[zhendong.su at inf dot ethz.ch via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118552

            Bug ID: 118552
           Summary: ICE on valid code at -O3 with "-fno-tree-ch
                    -fno-tree-ccp -fno-tree-fre" on x86_64-linux-gnu: in
                    check_loop_closed_ssa_def, at
                    tree-ssa-loop-manip.cc:647
           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: ---

Compiler Explorer: https://godbolt.org/z/8bWreE4fa

Also see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114948

[509] % 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/15.0.1/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
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 15.0.1 20250119 (experimental) (GCC) 
[510] % 
[510] % gcctk -O3 -fno-tree-ch -fno-tree-ccp -fno-tree-fre small.c
during GIMPLE pass: cunroll
small.c: In function ‘main’:
small.c:3:5: internal compiler error: in check_loop_closed_ssa_def, at
tree-ssa-loop-manip.cc:647
    3 | int main() {
      |     ^~~~
0x26d8a36 internal_error(char const*, ...)
        ../../gcc-trunk/gcc/diagnostic-global-context.cc:517
0xac3734 fancy_abort(char const*, int, char const*)
        ../../gcc-trunk/gcc/diagnostic.cc:1722
0x9005f9 check_loop_closed_ssa_def
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:647
0x13f1804 check_loop_closed_ssa_bb
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:661
0x13f33fe verify_loop_closed_ssa(bool, loop*)
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:697
0x13f33fe verify_loop_closed_ssa(bool, loop*)
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:681
0x13d9e69 tree_unroll_loops_completely
        ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1623
0x13d9f05 execute
        ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1727
0x13d9f05 execute
        ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1717
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.
[511] % 
[511] % cat small.c
volatile int a;
int b, c, d, e;
int main() {
  int f = 1, g = 1;
h:
  if (!d)
    ;
  else {
    int i = 1;
  j:
    e = 0;
    for (; e < 3; e++) {
      if (e)
        for (; g < 2; g++) {
          if (c)
            return 0;
          if (f)
            goto j;
        }
      a;
      if (i)
        continue;
      f = i = 0;
    }
  }
  f = 2;
  b++;
  if (c)
    goto h;
  return 0;
}