LLVM essentials : become familiar with the LLVM infrastructure and start using LLVM libraries to design a compiler

✍ Scribed by Pandey, Mayur; Sarda, Suyog

• Publisher: Packt Publishing
• Year: 2015
• Tongue: English
• Leaves: 236
• Series: Community experience distilled.
• Category: Library

✦ Synopsis

Annotation

Become familiar with the LLVM infrastructure and start using LLVM libraries to design a compiler
About This Book Learn to use the LLVM libraries to emit intermediate representation (IR) from high-level language Build your own optimization pass for better code generation Understand AST generation and use it in a meaningful wayWho This Book Is ForThis book is intended for those who already know some of the concepts of compilers and want to quickly get familiar with the LLVM infrastructure and the rich set of libraries that it provides.What You Will Learn Get an introduction to LLVM modular design and LLVM tools Convert frontend code to LLVM IR Implement advanced LLVM IR paradigms Understand the LLVM IR Optimization Pass Manager infrastructure and write an optimization pass Absorb LLVM IR transformations Understand the steps involved in converting LLVM IR to Selection DAG Implement a custom target using the LLVM infrastructure Get a grasp of C's frontend clang, an AST dump, and static analysisIn DetailLLVM is currently the point of interest for many firms, and has a very active open source community. It provides us with a compiler infrastructure that can be used to write a compiler for a language. It provides us with a set of reusable libraries that can be used to optimize code, and a target-independent code generator to generate code for different backends. It also provides us with a lot of other utility tools that can be easily integrated into compiler projects.This book details how you can use the LLVM compiler infrastructure libraries effectively, and will enable you to design your own custom compiler with LLVM in a snap.We start with the basics, where you'll get to know all about LLVM. We then cover how you can use LLVM library calls to emit intermediate representation (IR) of simple and complex high-level language paradigms. Moving on, we show you how to implement optimizations at different levels, write an optimization pass, generate code that is independent of a target, and then map the code generated to a backend. The book also walks you through CLANG, IR to IR transformations, advanced IR block transformations, and target machines.By the end of this book, you'll be able to easily utilize the LLVM libraries in your own projects.Style and approachThis book deals with topics sequentially, increasing the difficulty level in a step-by-step approach. Each topic is explained with a detailed example, and screenshots are included to help you understand the examples.  Read more...

✦ Table of Contents

Cover
Copyright
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Table of Contents
Preface
Chapter 1: Playing with LLVM
Modular design and collection of libraries
Getting familiar with LLVM IR
LLVM tools and using them in the command line
Summary
Chapter 2: Building LLVM IR
Creating an LLVM module
Emitting a function in a module
Adding a block to a function
Emitting a global variable
Emitting a return statement
Emitting function arguments
Emitting a simple arithmetic statement in a basic block
Emitting if-else condition IR
Emitting LLVM IR for loop
Summary. Chapter 3: Advanced LLVM IRMemory access operations
Getting the address of an element
Reading from the memory
Writing into a memory location
Inserting a scalar into a vector
Extracting a scalar from a vector
Summary
Chapter 4: Basic IR Transformations
Opt Tool
Pass and Pass Manager
Using other Pass info in current Pass
AnalysisUsage::addRequired method
AnalysisUsage:addRequiredTransitive method
AnalysisUsage::addPreserved method
Instruction simplification example
Instruction Combining
Summary
Chapter 5: Advanced IR Block Transformations
Loop processing. Scalar evolutionLLVM intrinsics
Vectorization
Summary
Chapter 6: IR to Selection DAG phase
Converting IR to selectionDAG
Legalizing SelectionDAG
Optimizing SelectionDAG
Instruction Selection
Scheduling and emitting machine instructions
Register allocation
Code Emission
Summary
Chapter 7: Generating Code for Target Architecture
Sample backend
Defining registers and register sets
Defining the calling convention
Defining the instruction set
Implementing frame lowering
Lowering instructions
Printing an instruction
Summary
Index.

✦ Subjects

Virtual computer systems;COMPUTERS / Operating Systems / Virtualization