You're reading from LLVM Code Generation A deep dive into compiler backend development

Product type Paperback

Published in May 2025

Publisher Packt

ISBN-13 9781837637782

Length 620 pages

Edition 1st Edition

Languages

C++

Tools

LLVM

Concepts

Programming Language

Author (1):

Quentin Colombet

View More author details

Table of Contents (30) Chapters

Preface

1. Part 1: Getting Started with LLVM

2. Building LLVM and Understanding the Directory Structure FREE CHAPTER

3. Contributing to LLVM

4. Compiler Basics and How They Map to LLVM APIs

5. Writing Your First Optimization

6. Dealing with Pass Managers

7. TableGen – LLVM Swiss Army Knife for Modeling

8. Part 2: Middle-End: LLVM IR to LLVM IR

9. Understanding LLVM IR

10. Survey of the Existing Passes

11. Introducing Target-Specific Constructs

12. Hands-On Debugging LLVM IR Passes

13. Part 3: Introduction to the Backend

14. Getting Started with the Backend

15. Getting Started with the Machine Code Layer

16. The Machine Pass Pipeline

17. Part 4: LLVM IR to Machine IR

18. Getting Started with Instruction Selection

19. Instruction Selection: The IR Building Phase

20. Instruction Selection: The Legalization Phase

21. Instruction Selection: The Selection Phase and Beyond

22. Part 5: Final Lowering and Optimizations

23. Instruction Scheduling

24. Register Allocation

25. Lowering of the Stack Layout

26. Getting Started with the Assembler

27. Unlock Your Book’s Exclusive Benefits

28. Other Books You May Enjoy

29. Index

Quiz time

Now that you have completed reading this chapter, try answering the following questions to test your knowledge:

Given the CLI name of an optimization, how can you check whether it is part of the middle end?

You can use the print-passes option from opt to check whether this name is part of one of the Module, Function, or Loop pass categories.

See the Leveraging opt section for more details.

Imagine that you have an existing pass that crashes on the output IR of one of your custom passes. What is one of the first things you can try before debugging the existing pass?

Start by putting the output IR through the verifier. Chances are your custom pass produces an invalid IR and this is what breaks the existing pass, since invalid IR must not be fed to passes.

See the The verifier section for more details.