Reducing the Functionality Gap Between Auto-Vectorization and Explicit Vectorization

Explicit vectorization of C/C++ and FORTRAN application programs are pioneered by Intel (R) Cilk (TM) Plus and then inherited and enhanced by OpenMP 4.0 and 4.5 standardization. There is a known functionality gap, where some auto-vectorizable code does not have adequate syntax support for explicit vector programming. In this paper, we propose and discuss a few syntax extensions to reduce the gap for compress/expand and histogram idioms, which are commonly seen in high performance computing.