SEGGER Toolchain

The SEGGER Toolchain is a professional C/C++ compilation and linking suite designed from the ground up for Arm and RISC-V embedded development. The SEGGER Compiler is a Clang-based optimising compiler that generates the smallest, fastest Thumb-2 code for Cortex-M and Cortex-A processors, benchmarks show it produces tighter code than both upstream Clang (by ~11%) and GCC (by ~18%) in size-optimised builds, and faster-executing code than both in speed-optimised builds. The SEGGER Linker complements this with up to 5.8x faster link times compared to the GNU Linker, along with seven distinct code-size optimisation passes that eliminate dead code, deduplicate functions and data, merge strings, and compress initialisation data.

Compiler: STOP Technology and Compatibility

The SEGGER Compiler’s standout safety feature is STOP, Stack Overflow Prevention, which automatically inserts stack limit checks before adjusting the stack pointer, preventing all stack overflows without any changes to application source code. This enables systems to enter a safe state and recover rather than silently corrupting memory. Because the compiler frontend is Clang-based with GCC-compatible invocation and language extensions, migrating existing projects typically requires changing a single build option.

Metric	SEGGER Compiler	Clang	GCC
Code size (-Oz)	100% (baseline)	~111%	~118%
Execution speed (-O3)	100% (baseline)	~112%	~113%
Stack safety	STOP built-in	Manual	Manual
Migration effort	N/A	1 build flag	1 build flag

Linker: Seven Optimisation Passes

Watch the SEGGER Embedded Studio introduction

The SEGGER Linker accepts ELF object files from any standard-conforming toolchain, GCC, Clang, or the SEGGER Compiler, and integrates with make and CMake build systems. Its seven optimisation techniques (modular linkage, flexible placement, dynamic runtime initialisation, initialisation compression, function deduplication, data deduplication, and string merging) work together to minimise final binary size. For RISC-V targets, additional architecture-specific optimisations including tail call optimisation, automatic inlining, outlining, smart relocation, and springboarding deliver further size reductions. The toolchain is available as part of SEGGER Embedded Studio and also for OEM licensing to third-party IDE and toolchain providers.