Machine Code

overview

Summary

Machine code is the CPU’s native binary language, defined by an architecture’s ISA. Instructions are encoded as opcodes plus fields for registers, immediates, and addressing modes, commonly shown in hex. Typical categories include load/store, arithmetic, logic, and control flow. Word size, endianness, and alignment affect layout and performance. Compilers and assemblers translate higher-level code to these encodings; disassemblers recover readable forms. Understanding instruction formats and memory effects is essential for optimization, debugging, and reasoning about undefined behavior.