看到「Base64 encoding and decoding at almost the speed of a memory copy」這個，可以超級快速編解碼 Base64 的資料。
實做上是透過 Intel 的 AVX-512 加速，在資料夠大的情況下 (超過 L1 cache 的大小)，可以達到接近字串複製的速度 (這邊提到的 memcpy())：
We show how we can encode and decode base64 data at nearly the speed of a memory copy (memcpy) on recent Intel processors, as long as the data does not fit in the first-level (L1) cache. We use the SIMD (Single Instruction Multiple Data) instruction set AVX-512 available on commodity processors. Our implementation generates several times fewer instructions than previous SIMD-accelerated base64 codecs.
不過這樣 AMD 暫時要哭哭...