[Cieric]

Some google searching brought up this. https://learn.microsoft.com/en-us/cpp/build/profile-guided-o... I'm only reading over it now, but I'm going to test it out a bit when I can.

[dwattttt]

PGO describes the using extra data to guide optimisations, but it doesn't define what those optimisations are.

Reading the link, there's several that sound like they match what BOLT is applying (Basic Block Optimization, Function Layout, Conditional Branch Optimization, and Dead Code Separation).