[Bug tree-optimization/111387] New: ICE on valid code at -O2 and -O3: verify_ssa failed

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111387

            Bug ID: 111387
           Summary: ICE on valid code at -O2 and -O3: 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: ---

This appears to be a recent regression.

Compiler Explorer: https://godbolt.org/z/9v9T5bfz9

[517] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/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 14.0.0 20230912 (experimental) (GCC) 
[518] % 
[518] % gcctk -O2 small.c
small.c: In function ‘main’:
small.c:6:5: error: definition in block 5 does not dominate use in block 2
    6 | int main() {
      |     ^~~~
for SSA_NAME: l_23 in statement:
_4 = {0, l_23};
during GIMPLE pass: slp
small.c:6:5: internal compiler error: verify_ssa failed
0x126622d verify_ssa(bool, bool)
        ../../gcc-trunk/gcc/tree-ssa.cc:1203
0xee7085 execute_function_todo
        ../../gcc-trunk/gcc/passes.cc:2095
0xee74db execute_todo
        ../../gcc-trunk/gcc/passes.cc:2142
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.
[519] % 
[519] % cat small.c
struct {
  unsigned a;
  unsigned b;
} c;
int d, e, f, g, h;
int main() {
  if (c.b && g && g > 7)
    goto i;
 j:
  if (c.a) {
    int k = 0;
    unsigned l = c.b;
    if (0) {
    m:
      k = l = c.b;
    }
    c.a = k;
    c.b = l;
  }
  if (0) {
  i:
    goto m;
  }
  if (d)
    goto j;
  for (f = 5; f; f--)
    if (h)
      e = 0;
  return 0;
}