So, as a quick synopsis of what's going on: I've converted the N64 renderer over to use the poly.h functionality provided by the core library, which should (in theory) provide a bump in speed by threading off individual polygon scanlines onto additional CPU cores. Currently, however, it's much slower due to various factors that I haven't quite ironed out, but more importantly it seems to be fond of crashing MESS, omitting flipped polygons, rendering garbage, and often scribbling over pre-existing pixels, which is not cool, and indicates thread unsafety. Which is bad, because I've been over it with a fine-toothed comb.
In the meantime, I might have to do a clean build, at which point I'll probably limit it to -j3 and entertain any viewers by playing MAME. :P