by petermcneeley
0 subcomment
- WebGPU (WGSL) handles this by having a specified accuracy for each operation.
https://www.w3.org/TR/WGSL/#concrete-float-accuracy
This is all fully tested in the CTS.
https://gpuweb.github.io/cts/standalone/?q=webgpu:shader,*
- > This is not the first time we can see Nvidia taking shortcuts to achieve maximum performance of their GPUs
Why is implementing it correctly not performant? For context I have no idea how rounding is typically implemented anyways.
by codedokode
0 subcomment
- Maybe we don't need denormals in most cases. Denormals are extremely tiny numbers (on order of 2^-149). It would be nice if RISC-V which aims for simpliciy, got rid of them. If you need such small numbers, I don't know, just use doubles or write your own floats.
- Another thing to keep in mind is that CPU processing of denormals tends to be extremely slow - I vaguely recall running into something like a 10x slowdown a decade ago.
For a lot of applications the difference between a denormal and zero is small enough to be irrelevant, so if you expect near-zero values to be common, enabling a denormals-to-zero compiler flag might give you a pretty nice performance boost for free.
- Flush denormals to zero. Even their inventor had trouble writing correct code in their presence - see the Appendix to that "what every programmer should know..." paper
- Denormals happen to be the way that Zero can even be represented at all?
by SwuduSusuwu
0 subcomment
- [dead]
- It's one of several issues with the design of IEEE floats, unfortunately. I wish we could start thinking more seriously about a new design, to complement if not replace IEEE in the long term. Posits are an example https://github.com/andrepd/posit-rust
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