LLVM toolchain for Linux on Arm

The LLVM toolchain includes Clang, LLD, BOLT, and other utilities for compiling, linking, profiling, and optimizing applications on Arm Linux.

In this guide, you’ll learn how to install LLVM from a prebuilt release or from source, install BOLT from Linux distribution packages, and verify the installed tools.

Before you begin

Confirm you are using an Arm machine by running:

Run:

    

        
        
uname -m

    

The output is similar to:

    

        
        aarch64

        
    

If you see a different result, you are not using an Arm computer running 64-bit Linux.

There are three ways to install the LLVM tools covered in this guide:

• Install LLVM from a prebuilt release to install Clang, LLD, BOLT, and the LLVM profiling tools.
• Build LLVM from source if you need to build the LLVM toolchain yourself.
• Install BOLT using a package manager if you only need the BOLT tools and your Linux distribution provides a suitable version.

Install from LLVM Releases

You can install LLVM by downloading a prebuilt binary release from GitHub.

Install the tools needed to download and extract the archive. For Debian-based Linux distributions, including Ubuntu, install wget and xz-utils:

    

        
        
sudo apt update
sudo apt install wget xz-utils -y

    

The following commands use LLVM version 22.1.8. To install a different version, replace the filename in the commands below. For the latest releases, see LLVM Project releases .

The commands extract LLVM to $HOME/toolchain. To install LLVM in a different location, adjust the extraction path and update the PATH environment variable accordingly.

1. Download a binary release

For Arm Linux, use the archive with Linux-ARM64 in its filename:

    

        
        
mkdir -p $HOME/toolchain
cd $HOME/toolchain
wget https://github.com/llvm/llvm-project/releases/download/llvmorg-22.1.8/LLVM-22.1.8-Linux-ARM64.tar.xz

    

2. Extract the downloaded file

    

        
        
tar -xvf LLVM-22.1.8-Linux-ARM64.tar.xz

    

3. Add the LLVM bin directory to your PATH

This enables you to run LLVM tools such as clang and lld from any directory. The command updates PATH for your current terminal session. To make the change persistent, add the same command to your shell profile, such as ~/.bashrc.

    

        
        
export PATH="$HOME/toolchain/LLVM-22.1.8-Linux-ARM64/bin:$PATH"

    

Install from Sources

Install source build dependencies

Before building LLVM from source, install the required build tools.

1. Install Git

Install Git for your operating system.

Many Linux distributions include Git so you may not need to install it.

2. Install CMake

    

        
        
sudo apt install cmake -y

    

Check it is installed:

    

        
        
cmake --version

    

The output is similar to:

    

        
        cmake version 3.28.3

CMake suite maintained and supported by Kitware (kitware.com/cmake).

        
    

For more information, see CMake install guide.

3. Install Ninja

    

        
        
sudo apt install ninja-build -y

    

Check it is installed:

    

        
        
ninja --version

    

The output is similar to:

    

        
        1.11.1

        
    

4. Install Clang

    

        
        
sudo apt install clang -y

    

Check it is installed:

    

        
        
clang --version

    

The output is similar to:

    

        
        Ubuntu clang version 18.1.3 (1ubuntu1)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

        
    

Build BOLT from source

To build and install BOLT from source code, follow these steps:

1. Clone the repository

    

        
        
git clone https://github.com/llvm/llvm-project.git

    

2. Build BOLT and run it

    

        
        
cd llvm-project
mkdir build
cd build
cmake -G Ninja ../llvm -DLLVM_TARGETS_TO_BUILD="X86;AArch64" -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_ASSERTIONS=ON -DLLVM_ENABLE_PROJECTS="bolt;clang;lld"

    

    

        
        
ninja bolt

    

3. Add the path to BOLT in your .bashrc file

    

        
        
echo 'export PATH="$PATH:$HOME/llvm-project/build/bin"' >> ~/.bashrc
source ~/.bashrc

    

After the build completes, continue to verify the BOLT tools .

Install BOLT using a package manager

Use a package manager if you prefer a system-managed installation. Package versions depend on your Linux distribution.

    

        
        

sudo apt update
sudo apt install llvm-bolt


    

    

        
        

sudo dnf install llvm-bolt


    

    

        
        

sudo zypper install llvm-bolt


    

BOLT is available on Ubuntu 25.04 and later, Debian 13 and later, Fedora 42 and later, and on openSUSE Tumbleweed

Verify Clang compiler and LLD linker tools

Run the following commands:

    

        
        
clang --version
clang++ --version
ld.lld --version

    

The output is similar to:

    

        
        clang version 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/ubuntu/toolchain/LLVM-22.1.8-Linux-ARM64/bin

clang version 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/ubuntu/toolchain/LLVM-22.1.8-Linux-ARM64/bin

LLD 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1) (compatible with GNU linkers)

        
    

Each command should print LLVM version information.

Compile and run a C++ example

Use a text editor to copy and paste the following code into a file named hello.cpp:

    

        
        
#include <iostream>

int main()
{
    std::cout << "Hello, LLVM on Arm\n";
    return 0;
}

    

Compile the example with clang++ and link it with LLD:

    

        
        
clang++ -fuse-ld=lld hello.cpp -o hello

    

Run the example:

    

        
        
./hello

    

The output is:

    

        
        Hello, LLVM on Arm

        
    

You are now ready to use LLVM on your Arm Linux system.

Verify the PGO profiling tools

Run the following commands:

    

        
        
llvm-profdata --version
llvm-profgen --version

    

Each command should print LLVM version information.

Verify BOLT tools

Run the following commands:

    

        
        
perf2bolt --version
llvm-bolt --version

    

The output is similar to:

    

        
        LLVM (http://llvm.org/):
  LLVM version 22.1.8
  Optimized build.

        
    

Each command should print LLVM version information.