Why ARM NEON not faster than plain C++?
The NEON pipeline on Cortex-A8 is in-order executing, and has limited hit-under-miss (no renaming), so you’re limited by memory latency (as you’re using more than L1/L2 cache size). Your code has immediate dependencies on the values loaded from memory, so it’ll stall constantly waiting for memory. This would explain why the NEON code is slightly … Read more