https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88739
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
So somehow build up exhaustive testing via
struct S # n # AT # m { \
T pad : m; \
T val : n; \
};
T __attribute__((noinline)) load8at0 () { return u.s8at0.val; }
...
union U {
T val;
struct S8at0 s8at0;
...
} u;
int main()
{
volatile T val = 0x0102030405060708;
u.val = val;
if (u.s8at0.val != load8at0 ())
__builtin_abort ();
...
return 0;
}
with T possibly unsigned __int128_t, for n in {8, 16, 32, 64}
and m in [0, 128 - n].
