Arm C/C++ Compiler

The Arm Compiler is the result of 20 years of development alongside the Arm architecture. The Arm Compiler toolchain incorporates a highly optimizing C/C++ compiler, assembler, linker and libraries for embedded software development.

Billions of devices containing software built with Arm tools have shipped to date, covering all embedded markets. Whether your industry is avionics, consumer electronics, mobile, industrial automation, automotive or medical, the Arm compiler can play a key role in optimizing your code.

Superior Performance

The highly efficient Arm Compiler invokes powerful optimization techniques such as loop unrolling, function inlining, idiom recognition, and architecture-specific instruction scheduling.

Superior Code Size Reduction

Drystone measurment of code size of Arm compiler

The Arm Compiler has a long embedded heritage, where memory space is a prized commodity. It incorporates techniques that can reduce your application footprint by up to 30% compared to other compilers. The Arm Compiler reduces the best code size by up to 5% compared to the RVDS 4.0 compiler.

For even more demanding memory limitations, the Arm Compiler includes an optional MicroLib C library for Cortex-M series microcontrollers, which provides up to a 50% reduction in code size compared to the full standard C library.

The MicroLib C library provides a completely C-based development environment without the need to revert to assembly language - even for interrupt service routines. This removes the need for specific knowledge of the Arm architecture.

Superior Value

Whether you are creating a modern application targeting a Cortex-M7 microcontroller or or rebuilding a 10-year-old library targeting the ARM7TDMI®, you only need a single license. An Keil MDK license works with older compiler versions, making modifications to legacy code easy.


The Arm Compiler features full support for C90, C99 and C++2003 with optimized routines for Arm and Thumb-2 which can greatly improve the performance of your code.

TÜV Certification, Compiler Qualification Kit & Extended Maintenance

TÜV SÜD seal for Arm compiler

With a TÜV certificate and a comprehensive Qualification Kit, Arm Compiler for functional safety greatly simplifies the overall Tool Qualification process, allowing end-users to focus on their end-product development.

Arm Compiler for functional safety is qualified for developing software that meets the highest level of safety integrity for the following standards:

  • IEC 61508 (Industrial) – SIL 3
  • ISO 26262 (Automotive) – ASIL D
  • EN 50128 (Railways) – SIL 4
  • IEC 62304 (Medical) – Class C

For other safety standards, many of which have been derived from IEC 61508, the Qualification Kit provides the key information required by end-users need to perform Tool Validation.

The Arm Compiler Qualification Kit consists of a significant body of supporting evidence derived from the compiler development process. This includes defect reports, C90/C99 test reports and a compiler safety manual, so that you can increase your confidence in the compliance to standards.

To complement this there is an option of Extended Maintenance and Support to protect your safety-critical projects against toolchain obsolescence. Initially supported in Arm Compiler, Extended Maintenance and Support is intended to maximize the stability of a fixed branch of the compiler toolchain by providing bug fixes and patches for a minimum of 5 years.

The Arm Compiler Qualification Kit with Extended Maintenance is available for MDK-Professional and the Arm Development Studio.