Embedded Operating System Optimization through Floating to Fixed Point Compiler Transformation

Architectures targeted at embedded systems often have limited floating point computation capabilities, and in many cases do not provide any hardware support. In this work, we propose a self-contained compiler transformation pass implemented within LLVM to perform floating point to fixed point conversion. This pass is used to optimize the scheduler of the MIOSIX embedded real-time operating system. We compare the proposed approach with the original floating point implementation, a hand-tuned fixed point one, and a solution based on a C++ library for fixed-point arithmetic. Our solution achieves speedups with respect to original floating point implementation up to 3.1×.