For some algorithms you have to compromise the data layout for compatibility across the widest number of microarchitectures by nerfing the performance on advanced SIMD microarchitectures working on the same data structures. There really isn’t a way to square that circle. You can make it portable or you can make it optimal, and the performance gap across those two implementations can be vast.
In the 15-20 years I’ve been doing it, I’ve seen zero evidence that there is a solution to this tradeoff. And people that are using SIMD are people that care about state-of-the-art performance, so portability takes a distant back seat.
In the 15-20 years I’ve been doing it, I’ve seen zero evidence that there is a solution to this tradeoff. And people that are using SIMD are people that care about state-of-the-art performance, so portability takes a distant back seat.