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

Introduction to the Backend

Now that you are familiar with the LLVM middle-end, you are ready to go deeper into the inner workings of the LLVM infrastructure.

This part introduces you to the backend part of the LLVM infrastructure, where you start dealing almost exclusively with target-specific constructs such as the registers or instructions available.

The backend part of LLVM features its own intermediate representation (IR), called the Machine IR, and its own pass pipeline, called the code generation (CodeGen) pipeline. Unlike the LLVM IR, the Machine IR is fully customizable, and one of the tasks of a backend author is to teach the LLVM infrastructure about the instruction set architecture (ISA) of their target.

Therefore, this part teaches you the following:

How to understand the Machine IR
How to augment the Machine IR with your target-specific instruction
How to describe the binary representation, called encoding, of your instructions and...