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Welcome to the LLVM Wiki.

This wiki is very much a work in progress - feel free to lend a hand.

The wiki is not intended to replace the 'official' documentation. It should serve as a supplement, especially for those developing on LLVM, detailing the very many aspects and intricacies of the LLVM system.

The wiki is publicly editable, so feel free to add whatever information you feel is relevant. We do ask that you try to follow the Wiki guidelines though.

Contents 1 Developing On LLVM 1.1 Tools for development 1.2 LLVM General 1.3 Analysis passes 1.4 Optimization passes 1.5 Backend 1.6 Common backend tasks 1.7 FAQ 1.8 Other 2 Developing LLVM 2.1 Active Projects 2.2 Proposed Projects 2.3 Wishlist 3 LLVM in the Future 4 Modifying LLVM-GCC 5 Using LLVM 6 Projects built on LLVM 6.1 Languages 6.2 Other 7 Getting started

[edit] Developing On LLVM

[edit] Tools for development

• Howto: Faster LLVM development
• Howto: Extend ghostview zoom range when displaying SelectionDAGs

[edit] LLVM General

• Nodes and Values
• Flags
• Chains
• DAGs
• Machine* classes vs Target* classes
• Using the casting infrastructure for your own classes

[edit] Analysis passes

• Alias
• PostDominators

[edit] Optimization passes

• Loop Rotation
• Loop Deletion
• HowTo: Insert a function call
• HowTo: Find all call sites of a function

[edit] Backend

• Absolute Minimum Backend
• TableGen
• Instruction Lowering
• Instruction Selection
• Emitting Assembly
• Emitting Code
• Understanding and writing an LLVM Compiler Backend

[edit] Common backend tasks

• About: FrameIndexes
• About: Function calls
• About: Debug Information
• HowTo: Expand nodes to library functions
• HowTo: Implement 8-bit memory access on a platform which only supports 32-bit memory operations
• HowTo: Implement calling conventions
• HowTo: Implement branching instructions
• HowTo: Implement conditional instructions
• HowTo: Implement addressing modes
• HowTo: Implement extending loads and truncating stores
• HowTo: Manage stack frame allocation
• HowTo: Implement reserved stack frames
• HowTo: Allocate stack space for return address
• HowTo: Add arbitrary properties to instructions

[edit] FAQ

• How do I emit '$' in an instruction using tblgen?
• How do I write an instruction pattern to copy between registers?
• How do I get the size of a Type at compile time?
• How do I compile on Visual C++?

[edit] Other

Raw notes/dumps. Should probably be folded into one of the above sections.

• Notes on setcc, select_cc, br_cc
• Minimal Backend Implementation

[edit] Developing LLVM

[edit] Active Projects

• Direct Object Code Emission
• Polly - The polyhedral optimization framework

[edit] Proposed Projects

• Provide more control over and access to JIT's output
• Inline assembler

[edit] Wishlist

• Universal Tablegen-based native assembler
• Universal Tablegen-based native disassembler

[edit] LLVM in the Future

• Chris Lattner's LLVM notes
• Embedded Metadata phase2
• Notes:Machine Code Emission in an ideal world

[edit] Modifying LLVM-GCC

• Local change markers
• HowTo: Add a builtin that maps to a custom LLVM intrinsic

[edit] Using LLVM

• HowTo: LLVM-based cross compiler
• HowTo: Generate c code from an IR file
• HowTo: JIT slowly-running machine code really quickly
• HowTo: Tell GDB about JITted code
• HowTo: Print native code emitted by the JIT
• HowTo: Call LLVM intrinsics from C code
• HowTo: Build JIT based Exception mechanism

[edit] Projects built on LLVM

[edit] Languages

• Pure
• LDC
• Roadsend PHP
• Unladen Swallow - Optimizing Python performance.
• PHP LLVM JIT
• llvm-lua, adds JIT and static compiling support to lua using LLVM.

[edit] Other

• TTA-based Codesign Environment

[edit] Getting started

• Configuration settings list
• MediaWiki FAQ
• MediaWiki release mailing list