Ubuntu Praises 5~7% PGO Compiler Optimization Performance Benefits

Summary (for building OpenSSL, Emacs, GDB, and Python) - "QEMU will be profiled only when building OpenSSL, and a new QEMU will be built using profiling data from this build"

The 5-7% improvement is seen when using QEMU on an x64 CPU to emulate a RISC-V CPU to build the 4 previously mentioned software projects.

So if you're building software that uses C, you'll probably see 5-7% improvement in RISC-V build times on an AMD x64 CPU.

I recall that Meta's BOLT optimizer can extract further reduction by optimizing software that has already been through PGO/FDO. ...assuming your workload matches the profiled workload. see https://github.com/llvm/llvm-project/blob/main/bolt/docs/Opt...