Firstly, we analyse the xchacha20 algorithm, showing what operations
are performed and in what order. Secondly, two innovative features
of SVP64 are described which are crucial to understanding of Simple-V
-Vectorisation: Vertical-First Mode and Indexed REMAP. Then we show
+Vectorization: Vertical-First Mode and Indexed REMAP. Then we show
how Index REMAP eliminates the need entirely for inline-loop-unrolling,
but note that in this particular algorithm REMAP is only useful for
us in Vertical-First Mode.