SIMD or not SIMD - cross platform

Question

I need some idea how to write a C++ cross platform implementation of a few parallelizable problems in a way so I can take advantage of SIMD (SSE, SPU, etc) if available. As well

Answer 1

Have you thought about using existing solutions like liboil? It implements lots of common SIMD operations and can decide at runtime whether to use SIMD/non-SIMD code (using function pointers assigned by an initialization function).