There are x86 extensions for fp16/bf16 ops. e.g. both Zen 4 and Zen 5 support AVX512_BF16, which has vdpbf16ps, i.e. dot product of pairs of bf16 elements from

There are x86 extensions for fp16/bf16 ops. e.g. both Zen 4 and Zen 5 support AVX512_BF16, which has vdpbf16ps, i.e. dot product of pairs of bf16 elements from two args; that is, takes a total of 64 bf16 elts and outputs 16 fp32 elts. Zen 5 can run two such instrs per cycle.