https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91987
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Another testcase, another reason:
int a[4] = { 1, 2, 3, 4 };
int b[4] = { 5, 6, 7, 8 };
int
foo (void)
{
int *x = a;
int r = x[(x = b, 3)];
if (x != b)
__builtin_abort ();
return r;
}
int
main ()
{
if (foo () != 3)
__builtin_abort ();
}
The problem here is that we somewhere fold the x[(x = b, 3)] which with
-fstrong-eval-order should have well defined ordering between x and (x = b, 3)
into
*(x + (x = b, 3)) which is undefined.
