Comprehensive Compiler Design Learning Roadmap

Phase 1

Prerequisites & Foundations

Data Structures & Algorithms

  • Trees (ASTs, parse trees, syntax trees)
  • Graphs (control flow graphs, data flow graphs)
  • Hash tables (symbol tables)
  • Stack operations (parsing, runtime)
  • String algorithms (pattern matching, lexical analysis)

Theory of Computation

  • Regular expressions and finite automata
  • Context-free grammars (CFGs)
  • Pushdown automata
  • Turing machines and computability
  • Chomsky hierarchy

Programming Language Concepts

  • Types and type systems
  • Scope and binding
  • Memory models
  • Control flow structures
  • Runtime environments
Phase 2

Frontend - Lexical & Syntax Analysis

Lexical Analysis (Scanning)

  • Role of the lexer in compilation
  • Token specification using regular expressions
  • Finite automata (DFA/NFA)
  • Converting regex to NFA to DFA
  • DFA minimization algorithms
  • Lexer generators and their operation
  • Handling keywords, identifiers, literals
  • Error detection and recovery in lexing
  • Buffering techniques for efficient scanning

Syntax Analysis (Parsing)

  • Context-free grammars fundamentals
  • Derivations and parse trees
  • Ambiguity in grammars
  • Top-down parsing
  • Recursive descent parsers
  • LL(1) parsing with FIRST/FOLLOW sets
  • Predictive parsing tables
  • Bottom-up parsing
  • LR(0) parsing
  • SLR parsing
  • LALR(1) parsing
  • Canonical LR(1) parsing
  • Handle pruning and shift-reduce conflicts
  • Error recovery strategies
  • Abstract Syntax Trees (AST) construction
  • Parser generators (Yacc/Bison)
Phase 3

Semantic Analysis

Type Systems

  • Static vs dynamic typing
  • Type checking algorithms
  • Type inference (Hindley-Milner)
  • Polymorphism (parametric, ad-hoc, subtype)
  • Type equivalence (structural vs nominal)
  • Coercion and conversion rules

Symbol Tables

  • Symbol table organization
  • Scope management (nested scopes)
  • Name resolution
  • Forward references
  • Storage allocation information

Semantic Actions

  • Syntax-directed translation
  • Attribute grammars (S-attributed, L-attributed)
  • Semantic rule evaluation
  • Declaration processing
  • Constant folding in semantic phase
Phase 4

Intermediate Representations

IR Design

  • Three-address code (TAC)
  • Static Single Assignment (SSA) form
  • Control Flow Graphs (CFG)
  • Basic blocks and flow graphs
  • Abstract syntax trees vs IR trees
  • High-level vs low-level IR

IR Transformations

  • Converting AST to IR
  • CFG construction
  • SSA construction (dominance frontiers)
  • Converting out of SSA form
  • IR normalization techniques
Phase 5

Code Optimization

Local Optimizations (Basic Block)

  • Common subexpression elimination
  • Copy propagation
  • Constant folding and propagation
  • Dead code elimination
  • Algebraic simplifications
  • Strength reduction

Global Optimizations (Control Flow)

  • Reaching definitions analysis
  • Available expressions analysis
  • Live variable analysis
  • Very busy expressions
  • Dominance analysis
  • Loop detection and natural loops

Dataflow Analysis Framework

  • Forward vs backward analysis
  • May vs must analysis
  • Lattice theory basics
  • Iterative dataflow algorithms
  • Worklist algorithms
  • Interprocedural dataflow

Advanced Optimizations

  • Loop-invariant code motion
  • Induction variable elimination
  • Loop unrolling
  • Loop fusion and fission
  • Inlining
  • Interprocedural constant propagation
  • Escape analysis
  • Pointer and alias analysis
  • Partial redundancy elimination (PRE)
  • Global value numbering (GVN)
  • Sparse conditional constant propagation

SSA-Based Optimizations

  • Sparse dataflow analysis
  • SSA-based dead code elimination
  • SSA-based constant propagation
  • Path-sensitive optimizations
Phase 6

Code Generation

Instruction Selection

  • Tree-pattern matching
  • Dynamic programming approaches
  • Maximal munch algorithm
  • BURS (Bottom-Up Rewrite System)
  • Instruction scheduling basics

Register Allocation

  • Live range analysis
  • Graph coloring algorithm
  • Chaitin's algorithm
  • Optimistic coloring
  • Linear scan allocation
  • Handling spills
  • Pre-colored registers and constraints
  • Coalescing and move elimination

Target Architecture Considerations

  • Machine-specific instruction sets
  • Calling conventions
  • Register classes and constraints
  • Addressing modes
  • Pipeline considerations
Phase 7

Runtime Systems

Memory Management

  • Stack allocation (activation records)
  • Heap allocation strategies
  • Mark and sweep
  • Reference counting
  • Copying collection
  • Generational GC
  • Incremental and concurrent GC

Linking and Loading

  • Object file formats (ELF, COFF, Mach-O)
  • Symbol resolution
  • Relocation
  • Dynamic linking
  • Position-independent code (PIC)

Runtime Support

  • Exception handling mechanisms
  • Virtual method dispatch
  • Type information at runtime (RTTI)
  • Reflection support
Phase 8

Advanced Topics

Just-In-Time (JIT) Compilation

  • Interpretation vs compilation trade-offs
  • Tiered compilation strategies
  • Profile-guided optimization
  • On-stack replacement (OSR)
  • Deoptimization techniques

Vectorization and Parallelization

  • Auto-vectorization (SIMD)
  • Loop vectorization
  • Dependence analysis
  • Parallelizing transformations
  • Polyhedral optimization

Advanced Analysis

  • Abstract interpretation
  • Symbolic execution
  • Program slicing
  • Points-to analysis (Andersen's, Steensgaard's)
  • Shape analysis

Domain-Specific Compilers

  • DSL compiler techniques
  • GPU compilers (CUDA, OpenCL)
  • Quantum computing compilers
  • SQL query compilation
  • Regular expression compilation

Core Algorithms

Lexical Analysis

  • Thompson's construction (regex to NFA)
  • Subset construction (NFA to DFA)
  • Hopcroft's DFA minimization
  • Brzozowski's algorithm

Parsing

  • Earley parser
  • CYK (Cocke-Younger-Kasami) algorithm
  • Packrat parsing (PEG)
  • GLR parsing (generalized LR)
  • Precedence climbing (operator precedence)

Type Checking & Inference

  • Algorithm W (Hindley-Milner)
  • Algorithm M (bidirectional type checking)
  • Unification algorithm
  • Subtyping algorithms

Optimization

  • Kildall's dataflow framework
  • Tarjan's algorithm (strongly connected components, dominators)
  • Lengauer-Tarjan (fast dominators)
  • Chaitin-Briggs register allocation
  • Lazy code motion
  • SCCP (Sparse Conditional Constant Propagation)
  • Value numbering algorithms

Graph Algorithms

  • Graph coloring (register allocation)
  • Dominator tree construction
  • Loop detection (finding back edges)
  • Strongly connected components (SCC)

Key Techniques

Program Analysis

  • Dataflow analysis (forward/backward, must/may)
  • Control flow analysis
  • Dependence analysis
  • Points-to and alias analysis
  • Escape analysis
  • Abstract interpretation
  • Symbolic execution

Transformation Techniques

  • Loop transformations (unrolling, tiling, interchange)
  • Outlining and inlining
  • Tail call optimization
  • Continuation-passing style (CPS)
  • Closure conversion
  • Lambda lifting

IR Techniques

  • SSA construction and destruction
  • Dominance frontiers
  • Phi-node placement
  • Critical edge splitting
  • Basic block normalization

Essential Tools & Frameworks

Lexer/Parser Generators

  • Flex/Lex (lexer)
  • Bison/Yacc (parser)
  • ANTLR (parser, multiple languages)
  • Ragel (state machine compiler)
  • Tree-sitter (incremental parsing)

Compiler Frameworks

  • LLVM (modular compiler infrastructure)
  • GCC (GNU Compiler Collection)
  • JVM (Java Virtual Machine)
  • V8 (JavaScript engine)
  • WebAssembly toolchain

Analysis & Optimization Tools

  • Souffle (Datalog engine for program analysis)
  • Soot (Java optimization framework)
  • WALA (program analysis for Java)
  • Frama-C (formal verification)

Backend Tools

  • LLVM TableGen (instruction selection)
  • Peephole optimizers
  • Assemblers (GNU as, NASM)
  • Linkers (GNU ld, LLD)

Debugging & Testing

  • Valgrind (memory debugging)
  • LLDB/GDB (debuggers)
  • AddressSanitizer, ThreadSanitizer
  • Fuzzing tools (AFL, LibFuzzer)

Cutting-Edge Developments

Machine Learning for Compilers

  • Learning heuristics for optimization passes
  • Phase ordering using reinforcement learning
  • Predictive modeling for compilation decisions
  • AutoTVM and AutoScheduler for tensor compilers
  • Neural architecture search for compiler optimizations
  • Synthesizing compiler optimizations
  • Superoptimization using ML
  • Neural program synthesis
  • Differentiable programming and compilers

Modern Language Features

  • Dependent types (Idris, Agda influence)
  • Linear types (Rust's ownership, session types)
  • Refinement types
  • Gradual typing systems
  • Effect systems and algebraic effects
  • Lock-free data structure compilation
  • Memory model semantics (C++11, Java)
  • Automatic parallelization improvements
  • Async/await implementation strategies
  • Actor model compilation

Hardware-Specific Compilation

  • CPU-GPU co-optimization
  • TPU and neural accelerator compilation
  • FPGA synthesis from high-level languages
  • Cross-device optimization
  • Quantum circuit optimization
  • Quantum IR design (QIR, OpenQASM)
  • Quantum-classical hybrid compilation
  • Error correction aware compilation

Security & Verification

  • Verified compiler implementations (CompCert)
  • Formally verified optimizations
  • Proof-carrying code
  • Certified compilation
  • Control-flow integrity (CFI)
  • Address space layout randomization (ASLR)
  • Spectre/Meltdown mitigations
  • Constant-time code generation
  • Side-channel resistant compilation

Domain-Specific Advances

  • TVM, Halide for image processing
  • XLA (Accelerated Linear Algebra)
  • MLIR (Multi-Level IR) ecosystem
  • Triton for GPU programming
  • Polyhedral compilation for deep learning
  • WASM optimization techniques
  • Ahead-of-time WASM compilation
  • WASI (WebAssembly System Interface)
  • Embedded and IoT compilation
  • IDE-friendly compilation
  • Incremental type checking
  • Query-based compilation
  • Language servers and compiler APIs

Energy & Performance

  • Power consumption optimization
  • Thermal-aware code generation
  • Energy profiling integration
  • Quality-configurable compilation
  • Trading accuracy for performance/energy
  • Probabilistic program analysis

Project Ideas

Beginner Projects

Beginner

1. Regular Expression Engine

  • Build a regex matcher using NFA/DFA
  • Implement Thompson's construction
  • Add capturing groups support

Skills: automata theory, basic algorithms

Beginner

2. Calculator Language Compiler

  • Lexer for arithmetic expressions
  • Recursive descent parser
  • AST construction and evaluation
  • Support variables and functions

Skills: parsing fundamentals, AST manipulation

Beginner

3. Simple Expression Evaluator

  • Infix to postfix conversion
  • Stack-based evaluation
  • Add support for variables

Skills: parsing, symbol tables

Beginner

4. Subset-of-C Lexer

  • Tokenize a minimal C subset
  • Handle keywords, identifiers, operators
  • Implement proper error reporting

Skills: lexical analysis, state machines

Beginner

5. Lisp/Scheme Interpreter

  • S-expression parser
  • Environment-based evaluation
  • Implement closures and first-class functions

Skills: functional programming, interpretation basics

Intermediate Projects

Intermediate

6. Static Type Checker

  • Type inference for a simple language
  • Implement Hindley-Milner algorithm
  • Support polymorphism
  • Generate meaningful error messages

Skills: type systems, unification

Intermediate

7. Basic C Compiler (to Assembly)

  • Parse C subset (functions, control flow, arrays)
  • Generate x86-64 or ARM assembly
  • Implement calling conventions
  • Basic optimizations (constant folding)

Skills: full compilation pipeline, code generation

Intermediate

8. Stack-Based VM and Compiler

  • Design bytecode instruction set
  • Compile expressions to bytecode
  • Implement VM with stack and locals
  • Add garbage collection

Skills: VM design, bytecode generation

Intermediate

9. SSA Form Converter

  • Build CFG from three-address code
  • Compute dominance frontiers
  • Insert phi nodes correctly
  • Implement optimization on SSA

Skills: IR design, graph algorithms

Intermediate

10. LLVM Frontend for Custom Language

  • Use LLVM C++ API
  • Generate LLVM IR
  • Leverage LLVM's optimization passes
  • Link with runtime library

Skills: LLVM ecosystem, IR generation

Intermediate

11. Basic Dataflow Analyzer

  • Implement reaching definitions
  • Live variable analysis
  • Available expressions
  • Use results for dead code elimination

Skills: dataflow analysis, optimization

Advanced Projects

Advanced

12. Optimizing Compiler with Multiple Passes

  • Implement 5-10 optimization passes
  • SSA-based optimizations
  • Register allocation with spilling
  • Instruction scheduling
  • Benchmark against GCC/Clang

Skills: advanced optimization, performance tuning

Advanced

13. JIT Compiler

  • Runtime code generation
  • Tiered compilation (interpreter to JIT)
  • Profile-guided optimization
  • Dynamic deoptimization

Skills: runtime compilation, profiling

Advanced

14. Garbage Collector Implementation

  • Mark-and-sweep collector
  • Generational GC
  • Concurrent collection
  • Integration with compiler

Skills: memory management, concurrency

Advanced

15. Polyhedral Optimizer

  • Dependence analysis for loops
  • Affine transformation framework
  • Tiling and parallelization
  • Use ISL (Integer Set Library)

Skills: mathematical optimization, advanced loops

Advanced

16. GPU/SIMD Auto-Vectorizer

  • Loop dependence analysis
  • Vectorization profitability model
  • Generate SIMD instructions (SSE/AVX/NEON)
  • Or CUDA/OpenCL kernels

Skills: parallelism, hardware architecture

Advanced

17. Interprocedural Optimizer

  • Call graph construction
  • Function inlining heuristics
  • Interprocedural constant propagation
  • Whole-program optimization

Skills: program-wide analysis

Advanced

18. Verified Compiler Component

  • Use Coq or Isabelle/HOL
  • Formalize a compiler pass
  • Prove correctness properties
  • Extract executable code

Skills: formal verification, theorem proving

Advanced

19. Tensor/ML Compiler

  • Operator fusion
  • Memory layout optimization
  • Auto-tuning for target hardware
  • Integration with ML frameworks

Skills: domain-specific compilation, performance

Advanced

20. Language with Advanced Type System

  • Implement dependent types or linear types
  • Type-level computation
  • Elaboration and proof search
  • Error messages with suggestions

Skills: advanced type theory, PL design

Advanced

21. Quantum Circuit Compiler

  • Quantum gate optimization
  • Qubit allocation
  • Transpilation to target architectures
  • Integration with Qiskit or Cirq

Skills: quantum computing, specialized optimization

Advanced

22. Compiler with MLIR

  • Multi-level IR transformations
  • Progressive lowering through dialects
  • Custom dialect for domain
  • Integration with LLVM backend

Skills: modern compiler infrastructure

Recommended Resources

Books

  • "Compilers: Principles, Techniques, and Tools" (Dragon Book) - Aho, Lam, Sethi, Ullman
  • "Modern Compiler Implementation in ML/C/Java" - Appel
  • "Engineering a Compiler" - Cooper & Torczon
  • "Advanced Compiler Design and Implementation" - Muchnick
  • "SSA-based Compiler Design" - Rastello & Bouchez
  • "Types and Programming Languages" - Pierce

Online Courses

  • Stanford CS143: Compilers
  • Cornell CS6120: Advanced Compilers
  • UCSD's Compilers course
  • MIT's Computer Language Engineering

Documentation & Tutorials

  • LLVM documentation and tutorials
  • GCC internals documentation
  • "Let's Build a Compiler" by Jack Crenshaw
  • LLVM Kaleidoscope tutorial

Research

  • PLDI, POPL, OOPSLA conference proceedings
  • CGO (Code Generation and Optimization)
  • TOPLAS journal