Preface

• Who this book is for
• What this book covers
• To get the most out of this book
• Get in touch

1. Getting Started with LLVM

2. Building LLVM and Understanding the Directory Structure FREE CHAPTER

• Technical requirements
• Getting ready for LLVM’s world
• Building a compiler
• Building LLVM
• Testing a compiler
• Understanding the directory structure
• Summary
• Quiz time

3. Contributing to LLVM

• Reporting an issue
• Engaging with the community
• Contributing patches
• Summary
• Quiz time

4. Compiler Basics and How They Map to LLVM APIs

• Technical requirements
• A word on APIs
• Understanding compiler jargon
• Working with basic structures
• Building your first IRs
• Summary
• Quiz time

5. Writing Your First Optimization

• Technical requirements
• The concept of value
• Tackling optimizations
• Loops
• Writing a simple constant propagation optimization
• Summary
• Quiz time

6. Dealing with Pass Managers

• Technical requirements
• What is a pass?
• What is a pass manager?
• The legacy and new pass manager
• Creating a pass
• Inspecting the pass pipeline
• Your turn
• Summary
• Further reading
• Quiz time

7. TableGen – LLVM Swiss Army Knife for Modeling

• Technical requirements
• Getting started with TableGen
• The TableGen programming language
• Discovering a TableGen backend
• Debugging the TableGen framework
• Summary
• Further reading
• Quiz time

8. Middle-End: LLVM IR to LLVM IR

9. Understanding LLVM IR

• Technical requirements
• Understanding the need for an IR
• Introducing LLVM IR
• Walking through an example
• Target-specific elements in LLVM IR
• Textual versus binary format
• LLVM IR API – cheat sheet
• Summary
• Further reading
• Quiz time

10. Survey of the Existing Passes

• Technical requirements
• How to find the unknown
• Survey of the helper passes
• Canonicalization passes
• Optimization passes
• Summary
• Further reading
• Quiz time

11. Introducing Target-Specific Constructs

• Technical requirements
• Adding a new backend in LLVM
• Creating your own intrinsics
• Adding a target-specific TargetTransformInfo implementation
• Customizing the default middle-end pipeline
• Using the right abstraction
• Summary
• Further reading
• Quiz time

12. Hands-On Debugging LLVM IR Passes

• Technical requirements
• The logging capabilities in LLVM
• Reducing the input IR size
• Using sanitizers
• A crash course on LLDB
• The LLVM code base through a debugger
• Summary
• Further reading
• Quiz time

13. Introduction to the Backend

14. Getting Started with the Backend

• Technical requirements
• Introducing the Machine IR
• Here comes the Machine IR
• The Machine IR textual representation
• The anatomy of a MachineInstr instance
• Working with registers
• Creating MachineInstr objects
• Describing registers
• Describing instructions
• Summary
• Further reading
• Quiz time

15. Getting Started with the Machine Code Layer

• Technical requirements
• The use of the MC layer
• Connecting the MC layer
• Enabling MC-based tools
• Summary
• Quiz time

16. The Machine Pass Pipeline

• Technical requirements
• The Machine pass pipeline at a glance
• Injecting passes
• Using the generic Machine optimizations
• Generic passes worth mentioning
• Summary
• Further reading
• Quiz time

17. LLVM IR to Machine IR

18. Getting Started with Instruction Selection

• Technical requirements
• Overview of the instruction selection frameworks
• Which selector to use?
• Selectors’ inner workings
• Understanding the DAG representation
• Understanding the generic Machine IR
• Groundwork to connect the codegen pipeline
• Summary
• Further reading
• Quiz time

19. Instruction Selection: The IR Building Phase

• Technical requirements
• Overview of the IR building
• Describing the calling convention
• Lowering the ABI with SDISel
• Lowering the ABI with FastISel
• Lowering the ABI with GlobalISel
• Summary
• Further reading
• Quiz time

20. Instruction Selection: The Legalization Phase

• Technical requirements
• Legalization overview
• Legalization actions
• Legalization in SDISel
• Legalization in GlobalISel
• Summary
• Quiz time

21. Instruction Selection: The Selection Phase and Beyond

• Technical requirements
• Register bank selection
• Instruction selection
• Finalizing the selection pipeline
• Optimizations
• Debugging the selectors
• Summary
• Quiz time

22. Final Lowering and Optimizations

23. Instruction Scheduling

• Technical requirements
• Overview of the instruction scheduling framework
• The ScheduleDAGInstrs class
• Changing the scheduling algorithm
• The scheduling model
• Implementing your scheduling model
• Summary
• Quiz time

24. Register Allocation

• Technical requirements
• Overview of register allocation in LLVM
• Enabling the register allocation infrastructure
• Introducing the slot indexes
• Introducing the live intervals
• Maintaining the live intervals
• Summary
• Further reading
• Quiz time

25. Lowering of the Stack Layout

• Technical requirements
• Overview of stack lowering
• The lowering of the stack frame
• The expansion of the frame indices
• Summary
• Quiz time

26. Getting Started with the Assembler

• Technical requirements
• Overview of the lowering of a textual assembly file
• Assembling with the LLVM infrastructure
• Implementing an assembler
• Summary
• Further reading
• Quiz time

27. Other Books You May Enjoy

28. Index