Dolphin's JITs have a minor terminology problem: The term "fastmem" can
refer to either the system of switching between a fast path and a slow
path using backpatching, or to the fast path itself. To hopefully make
things clearer, I'm adding some new terms, defining the old and new
terms as follows:
Fastmem: The system of switching from a fast path to a slow path by
backpatching when an invalid memory access occurs.
Fast access: A code path that accesses guest memory without calling C++
code.
Slow access: A code path that accesses guest memory by calling C++ code.