Ozaki scheme, maybe support FP128? - DGEMM without FP64 Arithmetic – Using FP64 Emulation and FP8 Tensor Cores with Ozaki Scheme

Internals & Design
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This scheme was new to me:
https://arxiv.org/pdf/2508.00441

It’s about GPUs. Got me thinking maybe this would also work for FP128, or CPUs (or GPUs).

It’s not simply double-double scheme (is that’s Dekker’s?). It doesn’t supports scalars (or well), pays off with large enough matrix. Probably Julia can’t do Float64 faster on CPUs, using Float32, I suppose all CPUs have as many units for, or half as fast bandwidth wise.

@photor

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For CPU it will be a lot slower than Quadmath.jl / libquadmath. CPUs have fast 64*64->128 multiply which is a much faster way to do 128 bit math.