[Bug tree-optimization/79327] New: wrong code at -O2 and -ftree-printf-return

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79327

            Bug ID: 79327
           Summary: wrong code at -O2 and -ftree-printf-return
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

The following aborts with -O2:

volatile int a, b = -1;
char buf[64];

int
main ()
{
  int c = a;
  int d = b;
  if (c >= -35791395 && c < 35791394 && d >= -1 && d < __INT_MAX__)
    {
      int e = __builtin_sprintf (buf, "%+03d%02d", c + 1, d + 1);
      if (e > 7)
        __builtin_abort ();
    }
  return 0;
}

-fno-printf-return-value helps.