For x64, you don't need to distribute multiple binaries. You can have one binary with variants of a function each optimized for a particular microarch, and reso

For x64, you don't need to distribute multiple binaries. You can have one binary with variants of a function each optimized for a particular microarch, and resolve which variant to use at runtime using the CPUID instruction. gcc already does this for you with function multiversioning, and glibc makes use of it for its string routines.