1 Packed Shift Mode Diagram
2 -------------------------
5 /-----------------^-----------------\ /-----------------^-----------------\
6 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
7 +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
8 | | | | | | | | | | | | | | | | | | | | | | | |
9 +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
10 | | | | | | | | | | | | | | | |
11 \ | \ | \ | \ | \ | \ | \ | \ |
12 3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | |
13 [][][][] [][][][] [][][][] [][][][] [][][][] [][][][] [][][][] [][][][]
14 | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0
15 | \ | \ | \ | \ | \ | \ | \ | \
16 | | | | | | | | | | | | | | | |
17 +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
18 | | | | | | | | | | | | | | | | | | | | | | | |
19 +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
20 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
21 \-----------------v-----------------/ \-----------------v-----------------/
24 <------- Direction of Shift