2019.11.21 23:51:45 (1197648825495818240) from Daniel J. Bernstein:
65.98 cycles/byte for SHA-512 on common Cortex-M4 microcontrollers (assuming all CPU options and no wait states). Best "optimizing" compiler result I've seen for reasonable C code is 110 cycles/byte, which is embarrassing for such a simple CPU. Does anyone have a better compiler?