[Bug tree-optimization/102711] [9/10/11 Regression] CDDCE removes condition that might lead to an infinite loop causing an unconditional infinite loop

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102711

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-10-12
     Ever confirmed|0                           |1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Just for refence this is the testcase that can be done at runtime:

void exit(int);
__attribute__((noipa))
int bar(void)
{
  static int t = 0;
  t++;
  if (t == 2) exit(0);
  return 1;
}
__attribute__((noipa))
void foo(void)
{
  if (!bar())
    for (;;);

  for (;;) {
    static int flag = 0;
    int ret = 0;
    bar();
    if (flag) {
      ret = bar();
      if (!ret)
        ret = bar();
    }
    flag = !bar();
    if (!ret)
      bar();
  }
}
int main(void)
{
  foo();
}