https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113678
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Noticed the same with:
```
void f(unsigned char *a, unsigned char *b, unsigned char *c)
{
unsigned char t[8];
t[0] = a[0];
t[1] = a[1];
t[2] = a[2];
t[3] = a[3];
t[4] = b[0];
t[5] = b[1];
t[6] = b[2];
t[7] = b[3];
c[0] = t[0];
c[1] = t[1];
c[2] = t[2];
c[3] = t[3];
c[4] = t[4];
c[5] = t[5];
c[6] = t[6];
c[7] = t[7];
}
```
Adding `-fno-tree-vectorize` gives the best code even.
