Don't be ridiculous, dude. No compiler is actually compiling to PCMPISTRI. It's meant to be used directly as assembly.
Of course I could be wrong. If you do know of any open-source compiler which compiles code to PCMPISTRI, let me know.
Superoptimization is not exactly exponential, it is NP-hard.
Of course, in the paranoid conspiracy I was referring to in my previous comment I predict the NSA/GCHQ is also using this directly via assembly. xD