In most of the cases I've seen where people felt the need for intrinsics, GCC will vectorize it -- at least if it's allowed to use the same potentially-incorrect semantics as the intrinsics version -- and potentially for multiple micro-architectures with GCC's target_clones attribute. GCC's -fopt-... flags can give you a lot of information on vectorization and other optimizations, if maybe couched in somewhat compiler-internal jargon, and other compiler probably do something similar. Vectorizing compilers have existed for 50-ish years, so it's well-established stuff.