Comparison of LLVM and GCC on the ARM Platform

Virtual machines provide platform independence by using intermediate code. Program source code is compiled into intermediate code, which can be executed on many different platforms. Even though there are many virtual machines, there are not many virtual machines that can support C/C++, especially with high performance. Recently, Low Level Virtual Machine (LLVM) provides limited degree of architecture independence for C programs. Though it does not support multi-platform execution of complex programs, it is able to run simple benchmarks, enabling us to look into important aspects. In this paper, we analyze the performance impact of using intermediate code for C programs in the embedded system. Compared to the traditional native execution, LLVM has a little weakness in handling memory accesses, but generally shows competitive performance in other optimizations. Especially, in a benchmark with frequent function calls, LLVM exhibits even better performance than GCC.