gcc/testsuite/gcc.dg/Warray-bounds-57.c

   1 /* PR middle-end/92323 - bogus -Warray-bounds after unrolling despite
   2    __builtin_unreachable
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall" } */
   5
   6 struct S { int a[5]; } s;
   7
   8 void sink (void*);
   9
  10 #pragma GCC optimize "2"
  11
  12 void f_O2 (unsigned n, struct S *p)
  13 {
  14   for (unsigned i = 1; i < n - 1; ++i)
  15     s.a[i - 1] = p->a[i];     // { dg-bogus "\\\[-Warray-bounds" }
  16
  17   if (n < 4 || n > 5)
  18     __builtin_unreachable ();
  19 }
  20
  21 void g_O2 (unsigned n, struct S *p)
  22 {
  23   if (n < 4 || n > 5)
  24     __builtin_unreachable ();
  25
  26   for (unsigned i = 1; i < n - 1; ++i)
  27     s.a[i - 1] = p->a[i];
  28 }
  29
  30
  31 // Also exercise -O3 with loop unrolling for good measure.
  32
  33 #pragma GCC optimize "3"
  34
  35 struct T { int a[6]; } t;
  36
  37 void f_O3 (unsigned n, struct T *p)
  38 {
  39   for (unsigned i = 1; i < n - 1; ++i)
  40     t.a[i - 1] = p->a[i];     // { dg-bogus "\\\[-Warray-bounds" }
  41
  42   if (n < 5 || n > 6)
  43     __builtin_unreachable ();
  44 }
  45
  46 void g_O3 (unsigned n, struct T *p)
  47 {
  48   if (n < 5 || n > 6)
  49     __builtin_unreachable ();
  50
  51   for (unsigned i = 1; i < n - 1; ++i)
  52     s.a[i - 1] = p->a[i];
  53 }