I guess it's these two files?
The original 2600+ lines of C++: https://gitlab.freedesktop.org/asahi/mesa/-/blob/main/src/ga...
The translated code: https://gitlab.freedesktop.org/asahi/mesa/-/blob/main/src/as...
The original 2600+ lines of C++: https://gitlab.freedesktop.org/asahi/mesa/-/blob/main/src/ga...
The translated code: https://gitlab.freedesktop.org/asahi/mesa/-/blob/main/src/as...
The code is quite low on comments and doesn't really explain the math there. It probably makes sense if you have background in the lofty math side of computer graphics, but that's a slightly different skillset than being able to reverse-engineer and bring up exotic hardware.
A lot of the size is just because the code deals with a lot of 3/4 dim stuff and also some things are a bit more verbose in code but translate to something short in assembly