[Bug tree-optimization/116879] New: ICE on valid code at -O2 with "-ftree-vectorize -fallow-store-data-races -fno-tree-ch -ftree-loop-distribution" on x86_64-linux-gnu: verify_ssa failed

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116879

            Bug ID: 116879
           Summary: ICE on valid code at -O2 with "-ftree-vectorize
                    -fallow-store-data-races -fno-tree-ch
                    -ftree-loop-distribution" 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: ---

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

[658] % 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 20240928 (experimental) (GCC) 
[659] % 
[659] % gcctk -O2 small.c; ./a.out
[660] % 
[660] % gcctk -O2 -ftree-vectorize -fallow-store-data-races -fno-tree-ch
-ftree-loop-distribution small.c
small.c: In function ‘main’:
small.c:3:5: error: definition in block 4 does not dominate use in block 8
    3 | int main() {
      |     ^~~~
for SSA_NAME: .MEM_12 in statement:
.MEM_3 = PHI <.MEM_12(8)>
PHI argument
.MEM_12
for PHI node
.MEM_3 = PHI <.MEM_12(8)>
during GIMPLE pass: vect
small.c:3:5: internal compiler error: verify_ssa failed
0x25e55a5 internal_error(char const*, ...)
        ../../gcc-trunk/gcc/diagnostic-global-context.cc:517
0x1452a3e verify_ssa(bool, bool)
        ../../gcc-trunk/gcc/tree-ssa.cc:1203
0x107e515 execute_function_todo
        ../../gcc-trunk/gcc/passes.cc:2108
0x107edbe execute_todo
        ../../gcc-trunk/gcc/passes.cc:2155
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.
[661] % 
[661] % cat small.c
static int b;
int *a, c, *d = &c;
int main() {
  int e = 0;
  for (; e < 8; e = (char)(e + 1)) {
    int *f = &b, g[8], h = 0;
    for (; h < 8; h++)
      g[h] = 0;
    --*f != (*d = g[0] || a);
  }
  return 0;
}