Streamlining Whole Function Vectorization in C Using Higher Order Vector Semantics

Taking full advantage of SIMD instructions in C programs still requires tedious and non-portable programming using intrinsics, despite considerable efforts spent developing auto-vectorization capabilities in recent decades. Whole Function Vectorization (WFV) is a recent technique for extending the use of SIMD across entire functions. WFV has so far only been used in data-parallel languages such as OpenCL and ISPC. We propose a vector-oriented programming framework that facilitates WFV directly in C. We show that our framework achieves competitive performance to Open CL and ISPC while maintaining C´s original syntax and semantics. This allows C programmers to gain better performance for their applications by improving SIMD utilization, without stepping out of C.