https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59875
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced testcase:
```
void foo1()
{
char *a[4] = {nullptr, nullptr, nullptr, nullptr};
char **b = &a[4];
while (b!=&a[0])
{
b--;
if (*b) __builtin_free(*b);
}
}
```
size: 10-3, last_iteration: 10-3
Loop size: 10
Estimated size after unrolling: 18
Not unrolling loop 3: contains call and code would grow.
There is another bug similar to this where we could decrease the cost slightly
if we know that a[i] is stored above and might eliminate the branch.
