Have you migrated from AC5 to AC6? Or switched from GCC to Keil? Let me know in the comments – I’d love to hear your performance numbers. Want more embedded toolchain deep dives? Subscribe to the newsletter.
For or tight memory systems, Keil often wins. You pay for predictability. 3. Three features you shouldn’t ignore a) Microlib A lightweight C library for deeply embedded systems. Reduces code size by ~50% compared to standard Arm libc—perfect for Cortex‑M0/M0+. b) Linker feedback files (.arf) Keil’s linker can generate feedback to the compiler, enabling link-time optimization (LTO) and unused-section elimination. GCC can do this too, but Keil makes it effortless. c) Event Recorder Not strictly a compiler feature, but tightly integrated: real-time software tracing without extra hardware. Great for debugging timing or logic issues. 4. Real-world performance example We benchmarked a control loop on a Cortex-M4 (STM32F4) – FIR filter + PID. keil arm compiler
| Compiler | Code size | Cycle count per iteration | |----------|-----------|----------------------------| | GCC -O2 | 14.2 KB | 128 cycles | | Keil AC6 -Oz | 10.8 KB | 112 cycles | | Keil AC6 -O3 | 12.1 KB | 96 cycles | Have you migrated from AC5 to AC6