[Bug debug/63572] [5 Regression] ICF breaks user debugging experience

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63572

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|jakub at redhat dot com            |

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
struct S { int a; int b; int c; };
volatile int t;

__attribute__((noinline)) static int
f1 (struct S *x)
{
  static int u = 1;
  int g = x->a * 7;
  t++;
  {
    static int v = 2;
    int h = x->b * 11;
    t++;
    int i = x->c;
    t++;
    return g + h + i;
  }
}

__attribute__((noinline)) static int
f2 (struct S *x)
{
  static int w = 3;
  int j = x->a * 7; t++; int k = x->b * 11; t++;
  {
    static int y = 4;
    int l = x->c;
    t++;
    return j + k + l;
  }
}

__attribute__((noinline)) int f3 (struct S *x) { return f1 (x); }
__attribute__((noinline)) int f4 (struct S *x) { return f2 (x) + 1; }
__attribute__((noinline)) int f5 (struct S *x) { return f1 (x) + 2; }
__attribute__((noinline)) int f6 (struct S *x) { return f2 (x) + 3; }

int
main ()
{
  struct S s = { 1, 2, 3 };
  asm volatile ("" : : "r" (&s) : "memory");
  int a[4];
  a[0] = f3 (&s);
  a[1] = f4 (&s);
  a[2] = f5 (&s);
  a[3] = f6 (&s);
  asm volatile ("" : : "r" (a) : "memory");
  return 0;
}

Even better testcase, which actually has more executable statements, and thus
allows to inspect if one sees e.g. the u/v/w/y/g/h/i/j/k/l variables in the
scope etc.