If you're doing new development and not opposed to using C++, I recommend xsimd, which provides a higher-level interface to architecture-specific SIMD instructions: https://github.com/xtensor-stack/xsimd
Apart from the fact that you have to rewrite your code, the big disadvantage to something like this is that it's a bit slower.
With SIMDe you're still free to use functions like `_mm_maddubs_epi16` and they'll be really fast on x86, but still work everywhere.
With xsimd (and similar libraries) you're generally limited to the lowest common denominator.
FWIW, if abstraction layers are your thing you might want to look at std::experimental::simd (https://github.com/VcDevel/std-simd) instead. Google's Highway (https://github.com/google/highway) is also pretty interesting.