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 608 pages

Edition 1st Edition

Languages

C++

Tools

LLVM

Concepts

Programming Language

Author (1):

Quentin Colombet

View More author details

Table of Contents (29) Chapters

Preface

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. 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. Introduction to the Backend

14. Getting Started with the Backend

15. Getting Started with the Machine Code Layer

16. The Machine Pass Pipeline

17. 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. Final Lowering and Optimizations

23. Instruction Scheduling

24. Register Allocation

25. Lowering of the Stack Layout

26. Getting Started with the Assembler

27. Other Books You May Enjoy

28. Index

Connecting the MC layer

Both the registers and the instruction descriptions contribute to defining the MC layer of your backend through the MCRegisterInfo and MCInstrInfo classes. In the examples of Chapter 11, we showed the minimal examples for these descriptions to work but they did not contain enough information to really grasp the interest of the MC layer.

In this section, we will show you how to augment these descriptions to be able to tap into the functionalities offered by the MC layer. In other words, now that you have grasped how to define registers and instructions, thanks to Chapter 11, we can focus on adding the assembly code and encoding support on top of this knowledge instead of mixing everything all at once.

We keep the plumbing part to the section named Enabling MC-based tools and instead focus in this section on how to augment your records with the proper information for MC enablement. Before we see what this looks like, let us step back and answer an obvious...