library to ease explicit vectorization of C++ code

 Vc is a free software library to ease explicit vectorization of C++
 code. It has an intuitive API and provides portability between
 different compilers and compiler versions as well as portability
 between different vector instruction sets. Thus an application
 written with Vc can be compiled for
  - AVX
  - SSE2 up to SSE4.2
  - SSE4a, XOP, and FMA4
  - Scalar (fallback which works everywhere)
  - LRBni support disabled, waiting for MIC