There’s ample information out there. There are quite a few text books, blogs, and YouTube videos covering computer architecture, including branch prediction.
> I've also found G_LIKELY and G_UNLIKELY in glib to be useful when writing some types of performance-critical code.
A lot of the time this is a hint to the compiler on what the expected paths are so it can keep those paths linear. IIRC, this mainly helps instruction cache locality.
For example: - Dan Luu has a nice write-up: https://danluu.com/branch-prediction/ - Wikipedia’s page is decent: https://en.m.wikipedia.org/wiki/Branch_predictor
> I've also found G_LIKELY and G_UNLIKELY in glib to be useful when writing some types of performance-critical code.
A lot of the time this is a hint to the compiler on what the expected paths are so it can keep those paths linear. IIRC, this mainly helps instruction cache locality.