input: [0] Auto-Vectorization (Enabled by /arch: and /Qx options) [1] Technique used to optimize loop performance through vector-level parallelism on Intel® processors by converting sequential instructions to SIMD instructions that can operate on multiple data elements at once [3] Resulting code may not run on all processors if processor-specific options are used [2] 
output: Automatic vector level parallelism done by the compiler Can be used together with other threading techniques