Comment by nwallin

Single pumped AVX512 can still be a lot more effective than double pumped AVX2.

AVX512 has 2048 bytes of named registers; AVX2 has 512 bytes. AVX512 uses out of band registers for masking, AVX2 uses in band mask registers. AVX512 has better options for swizzling values around. All (almost all?) AVX512 instructions have masked variants, allowing you to combine an operation and a subsequent mask operation into a single operation.

Often times I'll write the AVX512 version first, and go to write the AVX2 version, and a lot of the special sauce that made the AVX512 version good doesn't work in AVX2 and it's real awkward to get the same thing done.