[Bug tree-optimization/114948] New: ICE on valid code at -O3 with "-fno-tree-ccp -fno-tree-ch" 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=114948

            Bug ID: 114948
           Summary: ICE on valid code at -O3 with "-fno-tree-ccp
                    -fno-tree-ch" 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: ---

It appears to be a recent regression as it doesn't reproduce with 13.2 and
earlier.

Compiler Explorer: https://godbolt.org/z/szY6nz1W3

[522] % 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/15.0.0/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
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 15.0.0 20240505 (experimental) (GCC) 
[523] % 
[523] % gcctk -O3 -fno-tree-ccp -fno-tree-ch small.c
during GIMPLE pass: cunroll
small.c: In function ‘main’:
small.c:2:5: internal compiler error: in check_loop_closed_ssa_def, at
tree-ssa-loop-manip.cc:647
    2 | int main() {
      |     ^~~~
0x89471d check_loop_closed_ssa_def
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:647
0x130e654 check_loop_closed_ssa_bb
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:661
0x131023e verify_loop_closed_ssa(bool, loop*)
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:697
0x131023e verify_loop_closed_ssa(bool, loop*)
        ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:681
0x12f54fe tree_unroll_loops_completely
        ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1569
0x12f5583 execute
        ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1673
0x12f5583 execute
        ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1663
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.
[524] % 
[524] % cat small.c
int a, b, c, d;
int main() {
  int *e = 0;
  for (; d; d++)
  L1:
    ;
 L2:
   if (a) {
     for (c = 0; c < 2; ++c) {
       int *h;
       int **i = &h;
       int **const *j = &i;
       int **const **k = &j;
       if (c) {
         if (b)
           goto L2;
         a = *e;
       }
     }
     goto L1;
   }
 return 0;
}