I understand the design of libsodium for sure, but because libsodium is well written I look at it for reference implementations of specific algorithms. In this particular case I needed a zero-dependency sha256 implementation and I turned to libsodium (and was a bit disappointed by the lack of an sse3 optimization.) Would you accept a pull request that folds in intel's reference implementation with sse3 for sha256?

Fun fact, sha256 in openssl pulls in asn1 parsing even after section garbage collection. Yup.