In C++, this can be achieved portably using the Highway library: https://github.com/google/highway

(Disclaimer: I work at Google, but not on this, and I am writing this in my personal capacity.)

Makes me wonder why IBM never tried to make a GPU at some point.

They sort of did with the Cell https://en.wikipedia.org/wiki/Cell_(processor)

Ah, you're right!

I didn't realize they actually made a version of the Cell for blade servers at the time