/* PR middle-end/92323 - bogus -Warray-bounds after unrolling despite __builtin_unreachable { dg-do compile } { dg-options "-O2 -Wall" } */ struct S { int a[5]; } s; void sink (void*); #pragma GCC optimize "2" void f_O2 (unsigned n, struct S *p) { for (unsigned i = 1; i < n - 1; ++i) s.a[i - 1] = p->a[i]; // { dg-bogus "\\\[-Warray-bounds" } if (n < 4 || n > 5) __builtin_unreachable (); } void g_O2 (unsigned n, struct S *p) { if (n < 4 || n > 5) __builtin_unreachable (); for (unsigned i = 1; i < n - 1; ++i) s.a[i - 1] = p->a[i]; } // Also exercise -O3 with loop unrolling for good measure. #pragma GCC optimize "3" struct T { int a[6]; } t; void f_O3 (unsigned n, struct T *p) { for (unsigned i = 1; i < n - 1; ++i) t.a[i - 1] = p->a[i]; // { dg-bogus "\\\[-Warray-bounds" } if (n < 5 || n > 6) __builtin_unreachable (); } void g_O3 (unsigned n, struct T *p) { if (n < 5 || n > 6) __builtin_unreachable (); for (unsigned i = 1; i < n - 1; ++i) s.a[i - 1] = p->a[i]; }