Using SIMD to Tell if the High Bit is Set

from blog openmymind.net, | ↗ original
One of the first Zig-related blog posts I wrote was an overview of SIMD with Zig. I recently needed to revisit this topic when enhancing my smtp client library. Specifically, SMTP mostly expects printable ASCII characters. Almost all other characters, including UTF-8 text, must be encoded. I found the various SMTP and MIME RFCs confusing. So I...