[Bug tree-optimization/90020] [7/8/9 regression] -O2 -Os x86-64 wrong code generated for GNU Emacs

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90020

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
/* { dg-do run } */
/* { dg-require-weak "" } */

void __attribute__((noinline,noclone))
check (int i)
{
  if (i == 0)
    __builtin_exit (0);
}

int i;
extern int x __attribute__((weak));

int main(int argc, char **argv)
{
  if (argc)
    {
      check (i);
      return x;
    }
  else
    {
      check (i);
      return x-1;
    }
  return 0;
}


FAILs at -O2 due to GIMPLE PRE and at -Os due to RTL hoist (if GIMPLE PRE
is fixed).