RISC-V Summit

Many libraries, such as OpenCV, FFmpeg, XNNPACK, and Eigen, utilize Arm or x86 SIMD Intrinsics to optimize programs for performance. With the emergence of RISC-V Vector Extensions (RVV), there is a need to migrate these performance legacy codes for RVV. Our prior work at RISC-V Summit 2023, USA, successfully enhanced the open-source library, SIMD Everywhere (SIMDe), to support the migration from ARM NEON to RISC-V Vector Extensions. In this talk, we will update the status of our open source upstream at SIMDe. In addition, we further explore the migration of quantum-secure encryption algorithms with the RISC-V Cryptography Extension to meet the needs of post-quantum cryptography. Through these efforts, we identify a critical issue: the translation of SIMD intrinsics often fails to utilize the wider vectors available on the target platform. To address this issue, we propose an aggregation optimization in the LLVM pass that collects short vector intrinsics to fully leverage the wider vectors provided by RISC-V vector extension. Our vector aggregation optimization further boosts performance of RVV-enhanced SIMDe from 4.350× to 11.020×.