They provide an optimized non-SIMD generic implementation. The version I posted is similar, speed-wise, and it supports in-place base64 encoding/decoding (i.e.

They provide an optimized non-SIMD generic implementation. The version I posted is similar, speed-wise, and it supports in-place base64 encoding/decoding (i.e. allowing aliasing, supporting the case of using one buffer for both input and output).