GCC 11 PGO With The AMD Ryzen 9 5950X For Faster Performance
While every bit of performance is great, with PGO needing accurate profiles for optimization and rather time-consuming/involved, it's not as trivial as some compiler optimizations.
The most extreme differences found were for the Apache web server performance when serving a rather basic HTML website with the concurrent client testing facilitated by Bombardier. The gains were huge but again the profiles were crafted just around this particular benchmark and likely far less beneficial for modern, large, dynamic websites.
Himeno saw around a 9% improvement after being PGO'ed.
The NCNN neural network library and Intel oneDNN were seeing some improvements thanks to PGO.