Streamlining Whole Function Vectorization in C Using Higher Order Vector Semantics

摘要

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.