[Bug c/80549] New: wrong code at -O2 and -O3 in both 32-bit and 64-bit modes on x86_64-linux-gnu (executable does not terminate)

["chengniansun at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80549

            Bug ID: 80549
           Summary: wrong code at -O2 and -O3 in both 32-bit and 64-bit
                    modes on x86_64-linux-gnu (executable does not
                    terminate)
           Product: gcc
           Version: 7.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: chengniansun at gmail dot com
  Target Milestone: ---

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 8.0.0 20170424 (experimental) [trunk revision 247088] (GCC) 
$ gcc-trunk -O2 small.c ; timeout -s 9 10 ./a.out
Killed
$ cat small.c
char a, b;
int c;
short d;
void fn1(int p1) {
  short e = 4;
  int f;
  d = 0;
  for (; d <= 0; d++)
    e = 0;
  if (e)
    goto L1;
L2:
  if (p1) {
    a = 9;
    for (; a; ++a) {
      f = 5;
      for (; f != 32; ++f)
        c = 8;
    L1:
      if (b)
        goto L2;
    }
  }
}

int main() {
  fn1(1);
  return 0;
}
$ 
$