Arm Toolchain for Linux

Arm Toolchain for Linux (ATfL) is an open-source LLVM-based compiler suite for AArch64 Linux systems. It includes the armclang C/C++ compiler, the armflang Fortran compiler, and Arm Performance Libraries (ArmPL). ATfL is optimized for Arm Neoverse cores and targets scientific computing, HPC, AI, and cloud-native workloads.

ATfL replaces the older Arm Compiler for Linux (ACfL), which reached end of life with version 24.10. If you are migrating from ACfL, see the Arm Toolchain for Linux User Guide for guidance.

ATfL runs on 64-bit Arm Linux machines and supports all 64-bit Arm-based server-class hardware . It isn’t a cross-compiler.

You don’t need any additional license to use Arm Toolchain for Linux.

Before you begin

Confirm you are using an Arm machine by running:

    

        
        
uname -m

    

The expected output is:

    

        
        aarch64

        
    

If you see a different result, you aren’t using an Arm computer running 64-bit Linux.

ATfL is supported on the following Linux distributions:

• Ubuntu 22.04 and 24.04
• Red Hat Enterprise Linux 8, 9, and 10
• Amazon Linux 2023
• SUSE Linux Enterprise Server 15 and 16

Install ATfL using the system package manager

The recommended way to install ATfL is through the Arm Toolchains repository . This method installs ATfL and Arm Performance Libraries using your system package manager and handles updates automatically.

Ubuntu

Install the Arm Toolchains repository package and then install ATfL:

    

        
        
curl -O https://developer.arm.com/packages/arm-toolchains/ubuntu/pool/arm-toolchains-repository_2-2~noble_all.deb
sudo dpkg -i arm-toolchains-repository_2-2~noble_all.deb
sudo apt update
sudo apt install -y arm-toolchain-for-linux

    

Red Hat Enterprise Linux 8

Install the repository package and then install ATfL:

    

        
        
sudo dnf install -y https://developer.arm.com/packages/arm-toolchains/rhel/el8/aarch64/arm-toolchains-repository-2-2.el8.noarch.rpm
sudo dnf clean all
sudo dnf makecache
sudo dnf install -y arm-toolchain-for-linux

    

Red Hat Enterprise Linux 9

Install the repository package and then install ATfL:

    

        
        
sudo dnf install -y https://developer.arm.com/packages/arm-toolchains/rhel/el9/aarch64/arm-toolchains-repository-2-2.el9.noarch.rpm
sudo dnf clean all
sudo dnf makecache
sudo dnf install -y arm-toolchain-for-linux

    

Red Hat Enterprise Linux 10

Install the repository package and then install ATfL:

    

        
        
sudo dnf install -y https://developer.arm.com/packages/arm-toolchains/rhel/el10/aarch64/arm-toolchains-repository-2-2.el10.noarch.rpm
sudo dnf clean all
sudo dnf makecache
sudo dnf install -y arm-toolchain-for-linux

    

Amazon Linux 2023

Install the repository package and then install ATfL:

    

        
        
sudo dnf install -y https://developer.arm.com/packages/arm-toolchains/amazonlinux/al2023/aarch64/arm-toolchains-repository-2-2.al2023.noarch.rpm
sudo dnf clean all
sudo dnf makecache
sudo dnf install -y arm-toolchain-for-linux

    

SUSE Linux Enterprise Server 15

Install the repository package and then install ATfL:

    

        
        
sudo zypper install -y https://developer.arm.com/packages/arm-toolchains/sles/sles15/aarch64/arm-toolchains-repository-2-2.sles15.noarch.rpm
sudo zypper clean
sudo zypper refresh
sudo zypper install -y arm-toolchain-for-linux

    

SUSE Linux Enterprise Server 16

Install the repository package and then install ATfL:

    

        
        
sudo zypper install -y https://developer.arm.com/packages/arm-toolchains/sles/sles16/aarch64/arm-toolchains-repository-2-2.sles16.noarch.rpm
sudo zypper clean
sudo zypper refresh
sudo zypper install -y arm-toolchain-for-linux

    

Set up the environment

ATfL installs to /opt/arm/arm-toolchain-for-linux. You need to add the bin directory to your PATH before using the compilers.

Option 1: Source the environment script

Source the provided env.bash script to configure your shell:

    

        
        
source /opt/arm/arm-toolchain-for-linux/env.bash

    

To load the environment automatically in new shells, add it to your .bashrc:

    

        
        
echo 'source /opt/arm/arm-toolchain-for-linux/env.bash' >> $HOME/.bashrc
source $HOME/.bashrc

    

Option 2: Use environment modules

ATfL provides module files for use with Environment Modules . Install the environment-modules package if it isn’t already present:

    

        
        
sudo apt install -y environment-modules

    

Set up your shell to use modules and load ATfL:

    

        
        
echo '. /usr/share/modules/init/bash' >> $HOME/.bashrc
echo 'module use /opt/arm/modulefiles' >> $HOME/.bashrc
source $HOME/.bashrc
module load atfl/22.1

    

To see all available modules, run:

    

        
        
module avail

    

Verify installation

After setting up the environment, verify the compiler versions:

    

        
        
armclang --version

    

The output is similar to:

    

        
        Arm Toolchain for Linux 22.1.0 clang version 22.1.0 (https://github.com/arm/arm-toolchain.git c95792353373404441df364b5a762338e5642230)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/arm/arm-toolchain-for-linux/bin
Configuration file: /opt/arm/arm-toolchain-for-linux/bin/clang.cfg
Arm Toolchain ID: L0054 (b1c6e086)

        
    

Also verify the Fortran compiler:

    

        
        
armflang --version

    

The output is similar to:

    

        
        Arm Toolchain for Linux 22.1.0 flang version 22.1.0 (https://github.com/arm/arm-toolchain.git c95792353373404441df364b5a762338e5642230)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/arm/arm-toolchain-for-linux/bin
Configuration file: /opt/arm/arm-toolchain-for-linux/bin/flang.cfg
Arm Toolchain ID: L0054 (b1c6e086)

        
    

Get started with the C/C++ compiler

Create a text file named hello.c with the following contents:

    

        
        
#include <stdio.h>

int main()
{
    printf("Hello, C World!\n");
    return 0;
}

    

Build and run the application:

    

        
        
armclang hello.c -o hello
./hello

    

The output is:

    

        
        Hello, C World!

        
    

Get started with the Fortran compiler

Create a text file named hello.f90 with the following contents:

    

        
        
program hello
  print *, 'Hello, Fortran World!'
end program hello

    

Build and run the application:

    

        
        
armflang hello.f90 -o hello
./hello

    

The output is:

    

        
         Hello, Fortran World!

        
    

Get started with Arm Performance Libraries

ATfL automatically installs Arm Performance Libraries (ArmPL) as a dependency. ArmPL provides optimized BLAS, LAPACK, FFT, and sparse routines tuned for Arm Neoverse processors.

To load the ArmPL environment module:

    

        
        
module load arm-performance-libraries

    

This sets the ARMPL_DIR environment variable and configures LD_LIBRARY_PATH and PKG_CONFIG_PATH.

For detailed usage instructions, see the Arm Performance Libraries install guide and the ArmPL documentation .