# Documentation for the LLVM System at SVN head

If you are using a released version of LLVM, see the download page to find your documentation.

LLVM Design LLVM Publications LLVM User Guides LLVM Programming Documentation LLVM Subsystem Documentation LLVM Development Process Documentation LLVM Mailing Lists |

Written by The LLVM Team

## LLVM Design & Overview

- LLVM Language Reference Manual - Defines the LLVM intermediate representation.
- Introduction to the LLVM Compiler - Presentation providing a users introduction to LLVM.
- Intro to LLVM - book chapter providing a compiler hacker's introduction to LLVM.
- LLVM: A Compilation Framework for Lifelong Program Analysis & Transformation - Design overview.
- LLVM: An Infrastructure for Multi-Stage Optimization - More details (quite old now).
- GetElementPtr FAQ - Answers to some very frequent questions about LLVM's most frequently misunderstood instruction.

## LLVM User Guides

- The LLVM Getting Started Guide - Discusses how to get up and running quickly with the LLVM infrastructure. Everything from unpacking and compilation of the distribution to execution of some tools.
- LLVM CMake guide - An addendum to the main Getting Started guide for those using the CMake build system.
- Getting Started with the LLVM System using Microsoft Visual Studio - An addendum to the main Getting Started guide for those using Visual Studio on Windows.
- LLVM Tutorial - A walk through the process of using LLVM for a custom language, and the facilities LLVM offers in tutorial form.
- Developer Policy - The LLVM project's policy towards developers and their contributions.
- LLVM Command Guide - A reference manual for the LLVM command line utilities ("man" pages for LLVM tools).
- LLVM's Analysis and Transform Passes - A list of optimizations and analyses implemented in LLVM.
- Frequently Asked Questions - A list of common questions and problems and their solutions.
- Release notes for the current release - This describes new features, known bugs, and other limitations.
- How to Submit A Bug Report - Instructions for properly submitting information about any bugs you run into in the LLVM system.
- LLVM Testing Infrastructure Guide - A reference manual for using the LLVM testing infrastructure.
- How to build the C, C++, ObjC, and ObjC++ front end - Instructions for building the clang front-end from source.
- Packaging guide - Advice on packaging LLVM into a distribution.
- The LLVM Lexicon - Definition of acronyms, terms and concepts used in LLVM.
- You can probably find help on the unofficial LLVM IRC channel. We often are on irc.oftc.net in the #llvm channel. If you are using the mozilla browser, and have chatzilla installed, you can join #llvm on irc.oftc.net directly.
- How To Add Your Build Configuration To LLVM Buildbot Infrastructure - Instructions for adding new builder to LLVM buildbot master.

## LLVM Programming Documentation

- LLVM Language Reference Manual - Defines the LLVM intermediate representation and the assembly form of the different nodes.
- The LLVM Programmers Manual - Introduction to the general layout of the LLVM sourcebase, important classes and APIs, and some tips & tricks.
- CommandLine library Reference Manual - Provides information on using the command line parsing library.
- LLVM Coding standards - Details the LLVM coding standards and provides useful information on writing efficient C++ code.
- Extending LLVM - Look here to see how to add instructions and intrinsics to LLVM.
- Doxygen generated documentation (classes) (tarball)
- ViewVC Repository Browser

## LLVM Subsystem Documentation

- Writing an LLVM Pass - Information on how to write LLVM transformations and analyses.
- Writing an LLVM Backend - Information on how to write LLVM backends for machine targets.
- The LLVM Target-Independent Code Generator - The design and implementation of the LLVM code generator. Useful if you are working on retargetting LLVM to a new architecture, designing a new codegen pass, or enhancing existing components.
- TableGen Fundamentals - Describes the TableGen tool, which is used heavily by the LLVM code generator.
- Alias Analysis in LLVM - Information on how to write a new alias analysis implementation or how to use existing analyses.
- Accurate Garbage Collection with LLVM - The interfaces source-language compilers should use for compiling GC'd programs.
- Source Level Debugging with LLVM - This document describes the design and philosophy behind the LLVM source-level debugger.
- Zero Cost Exception handling in LLVM - This document describes the design and implementation of exception handling in LLVM.
- Bugpoint - automatic bug finder and test-case reducer description and usage information.
- LLVM Bitcode File Format - This describes the file format and encoding used for LLVM "bc" files.
- System Library - This document describes the LLVM System Library (`lib/System`) and how to keep LLVM source code portable
- Link Time Optimization - This document describes the interface between LLVM intermodular optimizer and the linker and its design
- The LLVM gold plugin - How to build your programs with link-time optimization on Linux.
- The GDB JIT interface - How to debug JITed code with GDB.
- Branch Weight Metadata - Provides information about Branch Prediction Information.

## LLVM Development Process Documentation

- LLVM Project Guide - How-to guide and templates for new projects that use the LLVM infrastructure. The templates (directory organization, Makefiles, and test tree) allow the project code to be located outside (or inside) the `llvm/` tree, while using LLVM header files and libraries.
- LLVMBuild Documentation - Describes the LLVMBuild organization and files used by LLVM to specify component descriptions.
- LLVM Makefile Guide - Describes how the LLVM makefiles work and how to use them.
- How To Release LLVM To The Public - This is a guide to preparing LLVM releases. Most developers can ignore it.

## LLVM Mailing Lists

- The LLVM Announcements List: This is a low volume list that provides important announcements regarding LLVM. It gets email about once a month.
- The Developer's List: This list is for people who want to be included in technical discussions of LLVM. People post to this list when they have questions about writing code for or using the LLVM tools. It is relatively low volume.
- The Bugs & Patches Archive: This list gets emailed every time a bug is opened and closed, and when people submit patches to be included in LLVM. It is higher volume than the LLVMdev list.
- The Commits Archive: This list contains all commit messages that are made when LLVM developers commit code changes to the repository. It is useful for those who want to stay on the bleeding edge of LLVM development. This list is very high volume.
- The Test Results Archive: A message is automatically sent to this list by every active nightly tester when it completes. As such, this list gets email several times each day, making it a high volume list.