How to Use PGO and LTO With Meson and Clang
A tested walkthrough for enabling Profile Guided Optimization and Link Time Optimization in a Meson project built with Clang, including the llvm-profdata merge step most guides forget.
Raphaël Fleury-le Veso
I write low-level C and C++ on FreeBSD, Linux and Yocto: security daemons, custom distributions, and the software underneath the software. Certified engineer in France. I write things up here once I’ve worked them out.
Latest posts
Part 2: Profiling, PGO & LTO
Measuring PGO and LTO on a C++ SPH simulation with perf and flamegraphs, and why they barely helped.
Optimizing an SPH Simulation, Part 1: Speed From the Compiler
Before touching a single line of my fluid simulation, I let the compiler do the work. Just changing flags got me from 1x to roughly 40x.
Bootloader-Agnostic Kernels : Crafting a Universal x86-64 entry trampoline
Multiboot2 drops you in 32-bit protected mode; Limine hands you a 64-bit environment. A single entry trampoline that handles both without forking the kernel.
Latest projects
Analysair
Air quality monitoring on a custom board.
Foyer
A ready-to-flash home server distribution, built with Yocto.
OS-R
A POSIX-compliant operating system for x86-64, written from scratch.
rflv.fr
The blog you are currently reading.
Latest readings
The Design of the UNIX Operating System
History and design of UNIX.
Computer Systems: A Programmer's Perspective
The book I hand to anyone who says they want to get into low-level programming.