RISC-V Auto-Vectorization Support For The GCC Compiler Started

A set of patches sent out this morning lay out the initial foundation for RISC-V auto-vectorization support within the GNU Compiler Collection (GCC).

This GCC RISC-V auto-vectorization support was sent out by Michael Collison of stealth mode start-up Rivos. The code was also worked on by RiVAI and Ju-Zhe Zhong. This auto-vectorization support is based on the current RISC-V "RVV" vector intrinsic support already upstream in the compiler.

The proposed code adds a new vector cost model, the auto-vectorization patterns, and support for integer addition and subtraction. Limiting it to integer addition and subtraction is just intended while this code is a proof-of-concept.

Those interested in this latest RISC-V GCC compiler work can see this patch series for that tentative code. This work is too late for this year's GCC 13 feature release but will hopefully be all squared away for next year's GCC 14.