[Bug tree-optimization/87168] New: ICE on valid code at -Os and above on x86_64-linux-gnu: verify_ssa failed

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87168

            Bug ID: 87168
           Summary: ICE on valid code at -Os and above 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: su at cs dot ucdavis.edu
  Target Milestone: ---

It is a recent regression. 

$ gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/9.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 9.0.0 20180830 (experimental) [trunk revision 263982] (GCC)
$
$ gcctk -O1 small.c
$ gcc-8.1.0 -Os small.c
$
$ gcctk -Os small.c
small.c: In function ‘main’:
small.c:3:5: error: definition in block 8 does not dominate use in block 7
3 | int main ()
  |     ^~~~
for SSA_NAME: j_27 in statement:
i_20 = (unsigned int) j_27;
during GIMPLE pass: cunrolli
small.c:3:5: internal compiler error: verify_ssa failed
0xefaca3 verify_ssa(bool, bool)
        ../../gcc-source-trunk/gcc/tree-ssa.c:1188
0xbb2653 execute_function_todo
        ../../gcc-source-trunk/gcc/passes.c:1950
0xbb2f79 execute_todo
        ../../gcc-source-trunk/gcc/passes.c:1997
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.
$


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


int a, b, c, d, e, f, *g;

int main ()
{ 
  unsigned i;
  while (b)
    { 
      int j, m;
    L1:
      f = j;
    L2:
      if (i && e)
          { 
            i = f;
            goto L2;
          }
      j = f;
      if (a)
        goto L3;
      for (m = 0; m < 2; m++)
        if (d)
          goto L1;
      goto L2;
    L3:
      (&j != g) | c;
    }
  return 0;
}