The benchmark measures the time to copy about 1 MiByte, in chunks of various lengths from 1 byte to 1 kilobyte. I wanted to take into account differences in ali

The benchmark measures the time to copy about 1 MiByte, in chunks of various lengths from 1 byte to 1 kilobyte. I wanted to take into account differences in alignment in the source and destination strings, so there are a few bytes between each source and destination string, which are not counted as part of the megabyte. On my Zen 4 CPU the L2 cache is 1 MiB per core, so because the working set is over 2 MB I think the relevant speed limit is the L3 cache. To be sure I was measuring what I thought I was, I compiled each function separately to avoid interference from inlining, code motion, loop fusion, etc. Of course in real code it's more likely that you would want to encourage inlining, not prevent it!