https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113326
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
One more thing:
```
vect_shift_0 = vect_value >> { 0, 1, 2, 3 };
vect_shift_1 = vect_value >> { 4, 5, 6, 7 };
vect_shift_2 = vect_value >> { 8, 9, 10, 11 };
vect_shift_3 = vect_value >> { 12, 13, 14, 15 };
```
vs
```
vect_shift_0 = vect_value >> { 0, 1, 2, 3 };
vect_shift_1 = vect_shift_0 >> { 4, 4, 4, 4 };
vect_shift_2 = vect_shift_0 >> { 8, 8, 8, 8 };
vect_shift_3 = vect_shift_0 >> { 12, 12, 12, 12 };
```
the first has fully independent operations while in the second case, there is
one dependent and the are independent operations.
On cores which has many vector units the first one might be faster than the
second one. So this needs a cost model too.
