ARM: NEON better instruction scheduling of over_n_8888
New head, tail, tail/head blocks are added and instructions
are reordered to eliminate pipeline stalls
Performance numbers of before/after
- cortex a8 -
before : L1: 375.39 L2: 391.93 M:114.39 ( 40.99%) HT: 99.37 VT: 98.20 R: 90.24 RT: 32.87 ( 240Kops/s)
after : L1: 481.90 L2: 483.46 M:114.29 ( 40.69%) HT:106.91 VT: 93.38 R: 90.74 RT: 29.51 ( 236Kops/s)
- cortex a9 -
before : L1: 324.50 L2: 332.79 M:155.55 ( 47.51%) HT:111.93 VT: 93.58 R: 71.92 RT: 28.21 ( 233Kops/s)
after : L1: 355.87 L2: 364.49 M:156.90 ( 47.59%) HT:111.52 VT: 91.76 R: 72.16 RT: 28.22 ( 234Kops/s)