Compiler Internals
A deep dive into the guts of a modern compiler.
Chapters in this path
How a C Program Becomes Machine Code: The C Compilation Process Explained
Trace the complete C compilation process from source code to executable binary. See each stage — preprocessing, compilation, assembly, and linking — with real GCC and Clang output across x86-64 and ARM64.
Compiler Lexer & Parser Demystified: How Compilers Read Your C Code
Learn how a compiler lexer and parser transform C source into tokens and ASTs. Hands-on with Clang's -dump-tokens and -ast-dump across real examples.
LLVM IR Tutorial: The Hidden Language Between Your C Code and Assembly
Master LLVM IR in this hands-on tutorial. Learn SSA form, basic blocks, and PHI nodes with real Clang output and Godbolt examples — from C to IR to x86-64 and ARM64.
The Ultimate Guide to Compiler Optimization Passes: Boosting Performance with -O2
You’ve been there. You write a complex calculation in C, compile it, and it feels a bit sluggish. You open your `Makefile`, add `-O2` to your `CFLAGS`, recompile, and suddenly your program is executing three times faster. But what actually is the compiler doing under the hood? Is it magic? Is it just removing debug…
Compiler Code Generation: How LLVM Turns IR into x86-64 and ARM64 Assembly
Between the hardware-agnostic world of LLVM Intermediate Representation (IR) and the raw binary bytes your CPU executes lies the backend pipeline—the most platform-specific, meticulously engineered phase of the compiler. In our previous deep dive into LLVM IR, we explored how the compiler represents your logic using an infinite number of virtual registers and generic instructions.…
Register Allocation in Compilers: How Variables Fit into CPU Registers
Discover how compilers solve register allocation — mapping thousands of virtual registers to 16 (x86-64) or 31 (ARM64) physical ones. See graph coloring, spilling, and rematerialization with real Godbolt examples.
Linker Explained: How Object Files Become Executables (Static & LTO)
Learn how the linker transforms object files into executables. Explore symbol resolution, relocation records, static vs dynamic linking, and Link-Time Optimization with real readelf and nm examples.
Write a Compiler from Scratch in C: Build a Working Toy Compiler
Learn how to write a compiler from scratch in C. Build a complete toy compiler with a hand-written lexer, recursive descent parser, and code generator targeting x86-64 and ARM64 assembly.