NOTE: If you are a user who is only interested in using an LLVM-based compiler, you should look into Clang instead. The documentation here is intended for users who have a need to work with the intermediate LLVM representation.
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:hidden: HowToBuildOnARM HowToBuildWithPGO HowToCrossCompileLLVM CoverageMappingFormat CFIVerify BuildingADistribution CMake Docker SupportLibrary AdvancedBuilds WritingAnLLVMNewPMPass WritingAnLLVMPass Passes StackSafetyAnalysis MergeFunctions AliasAnalysis MemorySSA MemProf LoopTerminology CycleTerminology Vectorizers LinkTimeOptimization DTLTO GoldPlugin Remarks SourceLevelDebugging HowToUpdateDebugInfo Instrumentor InstrRefDebugInfo RemoveDIsDebugInfo KeyInstructionsDebugInfo InstrProfileFormat InstCombineContributorGuide WritingAnLLVMBackend CodeGenerator TableGen/index MCJITDesignAndImplementation ORCv2 JITLink DebuggingJITedCode CommandLine ExtendingLLVM AddingConstrainedIntrinsics HowToBuildWindowsItaniumPrograms HowToCrossCompileBuiltinsOnArm BigEndianNEON AArch64SME CompileCudaWithLLVM NVPTXUsage AMDGPUUsage AMDGPUAsyncOperations AMDGPUDMAOperations AMDGPUExecutionSynchronization AMDGPUMemoryModel SPIRVUsage DirectXUsage RISCVUsage RISCV/RISCVVectorExtension RISCV/RISCVVCIX SandboxIR Telemetry LFI AdminTasks Benchmarking CMakePrimer CodeOfConduct FatLTO GitHub MarkdownQuickstartTemplate MisExpect OpaquePointers NewPassManager ReportingGuide ResponseGuide TableGenFundamentals yaml2obj
{doc}HowToBuildOnARM
Notes on building and testing LLVM/Clang on ARM.
{doc}HowToBuildWithPGO
Notes on building LLVM/Clang with PGO.
{doc}HowToCrossCompileLLVM
Notes on cross-building and testing LLVM/Clang.
How to build the C, C++, ObjC, and ObjC++ front end
Instructions for building the clang front-end from source.
{doc}CoverageMappingFormat
This describes the format and encoding used for LLVM’s code coverage mapping.
{doc}CFIVerify
A description of the verification tool for Control Flow Integrity.
{doc}BuildingADistribution
A best-practices guide for using LLVM's CMake build system to package and distribute LLVM-based tools.
{doc}CMake
An addendum to the main Getting Started guide for those using the CMake build system.
{doc}Docker
A reference for using Dockerfiles provided with LLVM.
{doc}Support Library <SupportLibrary>
This document describes the LLVM Support Library (lib/Support) and how to keep LLVM source code portable.
{doc}AdvancedBuilds
This document describes more advanced build configurations.
{doc}WritingAnLLVMNewPMPass
Information on how to write LLVM transformations under the new pass manager.
{doc}WritingAnLLVMPass
Information on how to write LLVM transformations and analyses under the legacy pass manager.
{doc}Passes
A list of optimizations and analyses implemented in LLVM.
{doc}StackSafetyAnalysis
This document describes the design of the stack safety analysis of local variables.
{doc}MergeFunctions
Describes functions merging optimization.
{doc}AliasAnalysis
Information on how to write a new alias analysis implementation or how to use existing analyses.
{doc}MemorySSA
Information about the MemorySSA utility in LLVM, as well as how to use it.
{doc}MemProf
User guide and internals of MemProf, profile guided optimizations for memory.
{doc}LoopTerminology
A document describing Loops and associated terms as used in LLVM.
{doc}CycleTerminology
A document describing cycles as a generalization of loops.
{doc}Vectorizers
This document describes the current status of vectorization in LLVM.
{doc}LinkTimeOptimization
This document describes the interface between LLVM intermodular optimizer and the linker and its design
{doc}DTLTO
This document describes the DTLTO implementation, which allows for distributing ThinLTO backend compilations without requiring support from the build system.
{doc}GoldPlugin
How to build your programs with link-time optimization on Linux.
{doc}Remarks
A reference on the implementation of remarks in LLVM.
{doc}Source Level Debugging with LLVM <SourceLevelDebugging>
This document describes the design and philosophy behind the LLVM source-level debugger.
{doc}How to Update Debug Info <HowToUpdateDebugInfo>
This document specifies how to correctly update debug info in various kinds of code transformations.
{doc}InstrRefDebugInfo
This document explains how LLVM uses value tracking, or instruction referencing, to determine variable locations for debug info in the final stages of compilation.
{doc}RemoveDIsDebugInfo
This is a migration guide describing how to move from debug info using intrinsics such as dbg.value to using the non-instruction DbgRecord object.
{doc}KeyInstructionsDebugInfo
This document explains how the debug info feature Key Instructions is implemented in LLVM.
{doc}InstrProfileFormat
This document explains two binary formats of instrumentation-based profiles.
{doc}InstCombineContributorGuide
This document specifies guidelines for contributions for InstCombine and related passes.
{doc}Instrumentor
A comprehensive guide to the highly configurable Instrumentor pass for custom program instrumentation, including the interactive configuration wizard.
{doc}WritingAnLLVMBackend
Information on how to write LLVM backends for machine targets.
{doc}CodeGenerator
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.
{doc}TableGen <TableGen/index>
Describes the TableGen tool, which is used heavily by the LLVM code generator.
{doc}MIRPatterns <GlobalISel/MIRPatterns>
Describes the design of MIR Patterns and how to use them.
{doc}MCJITDesignAndImplementation
Describes the inner workings of MCJIT execution engine.
{doc}ORCv2
Describes the design and implementation of the ORC APIs, including some usage examples, and a guide for users transitioning from ORCv1 to ORCv2.
{doc}JITLink
Describes the design and APIs for the JITLink library, ORC's new JIT linker.
{doc}DebuggingJITedCode
How to debug JITed code with GDB.
{doc}CommandLine
Provides information on using the command line parsing library.
{doc}ExtendingLLVM
Look here to see how to add instructions and intrinsics to LLVM.
{doc}AddingConstrainedIntrinsics
Gives the steps necessary when adding a new constrained math intrinsic to LLVM.
{doc}HowToBuildWindowsItaniumPrograms
Notes on assembling a Windows Itanium environment.
{doc}HowToCrossCompileBuiltinsOnArm
Notes on cross-building and testing the compiler-rt builtins for Arm.
{doc}BigEndianNEON
LLVM's support for generating NEON instructions on big endian ARM targets is somewhat nonintuitive. This document explains the implementation and rationale.
{doc}AArch64SME
LLVM's support for AArch64 SME ACLE and ABI.
{doc}CompileCudaWithLLVM
LLVM support for CUDA.
{doc}NVPTXUsage
This document describes using the NVPTX backend to compile GPU kernels.
{doc}AMDGPUUsage
This document describes using the AMDGPU backend to compile GPU kernels.
{doc}AMDGPUAsyncOperations
Asynchronous operations and the asyncmark mechanism for tracking their completion on AMD GPUs.
{doc}AMDGPUDMAOperations
DMA operations that transfer data between global memory and LDS on AMD GPUs.
{doc}AMDGPUMemoryModel
This document describes AMDGPU Memory Model which overrides the {ref}LLVM memory model <memmodel> when a program is compiled for the AMDGPU target.
{doc}AMDGPUDwarfExtensionsForHeterogeneousDebugging
This document describes DWARF extensions to support heterogeneous debugging for targets such as the AMDGPU backend.
{doc}AMDGPUDwarfExtensionAllowLocationDescriptionOnTheDwarfExpressionStack/AMDGPUDwarfExtensionAllowLocationDescriptionOnTheDwarfExpressionStack
This document describes a DWARF extension to allow location descriptions on the DWARF expression stack. It is part of {doc}AMDGPUDwarfExtensionsForHeterogeneousDebugging.
{doc}AMDGPUExecutionSynchronization
This document describes how execution of threads can be synchronized on AMD GPUs.
{doc}SPIRVUsage
This document describes using the SPIR-V target to compile GPU kernels.
{doc}DirectXUsage
This document describes using the DirectX target to compile GPU code for the DirectX runtime.
{doc}RISCVUsage
This document describes using the RISC-V target.
{doc}RISCV/RISCVVectorExtension
This document describes how the RISC-V Vector extension can be expressed in LLVM IR and how code is generated for it in the backend.
{doc}RISCV/RISCVVCIX
This document shows how the scheduling information for RISC-V's XSfvcp extension -- SiFive Vector Coprocessor Interface (VCIX) -- works and how to customize them.
{doc}Sandbox IR <SandboxIR>
This document describes the design and usage of Sandbox IR, a transactional layer over LLVM IR.
{doc}Telemetry
This document describes the Telemetry framework in LLVM.
{doc}LFI <LFI>
This document describes the Lightweight Fault Isolation (LFI) target in LLVM.