Explore GCC and Clang/LLVM compiler optimizations for Embedded Linux development in this comprehensive conference talk. Discover how to boost performance and reduce size on constrained systems through specific command-line options, architecture-specific tunings, and code-writing techniques. Learn to balance power, performance, and size optimizations while focusing primarily on C with some coverage of C++. Gain insights into writing compiler-friendly code, leveraging profile-guided optimization, link-time optimization, and auto-vectorization. Delve into CPU optimizations, builtin functions, and unsupported extensions to enhance your embedded Linux projects across multiple architectures.