[Bug tree-optimization/91200] New: ICE on valid code at -O1: verify_ssa failed

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91200

            Bug ID: 91200
           Summary: ICE on valid code at -O1: verify_ssa failed
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

It appears to be a recent regression.

[512] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/home/suz/software/gcctk/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/10.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --disable-multilib
--enable-languages=c,c++,lto --prefix=/home/suz/software/gcctk/gcc-trunk
--disable-bootstrap
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.0.0 20190718 (experimental) [trunk revision 273570] (GCC) 
[513] % 
[513] % gcctk -O0 small.c
[514] % gcc-9.1.0 -O1 small.c
[515] % 
[515] % gcctk -O1 small.c
small.c: In function ‘main’:
small.c:6:5: error: definition in block 4 does not dominate use in block 3
    6 | int main ()
      |     ^~~~
for SSA_NAME: i_20 in statement:
# VUSE <.MEM_13>
cstore_6 = MEM <int *[2]> [(void *)&h][i_20];
during GIMPLE pass: cselim
small.c:6:5: internal compiler error: verify_ssa failed
0xed1acb verify_ssa(bool, bool)
        ../../gcc-source-trunk/gcc/tree-ssa.c:1208
0xb861d7 execute_function_todo
        ../../gcc-source-trunk/gcc/passes.c:1970
0xb87102 execute_todo
        ../../gcc-source-trunk/gcc/passes.c:2017
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
[516] % 


-------------------------------------------


int printf (const char *, ...);

char a;
int b, c, **d;

int main ()
{
  int f = -128, *g, *h[2] = {0, 0}, i;
  printf("0");
  if (a)
    {
      while (f > a) {
        int *j = &i;
        *j |= 0;
      }
      h[i] = &c;
    }
  if (h[1])
    {
      int **k = &g;
      *k = &f;
      while (i)
        {
          int **l[] = {&g};
        }
      int **m = &g;
      *d = *m = &b;
    }
  return 0;
}