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Comment by BeeOnRope | Hacker News Reader

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BeeOnRope

Finally a third independent source for x86 instruction timings, joining Agner [1] and instlatx64 [2].

Is the testing code open source? There is no obvious link from the main page.

[1] https://www.agner.org/optimize/#manuals

[2] http://users.atw.hu/instlatx64/

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The testing code is not open source yet, but we plan to make it available in the near future. We are also working on a code analysis tool, similar to Intel's IACA, that uses the instruction data from http://www.uops.info/. Finally, we also plan to add data for AMD processors.

Cool. Is is the IACA-alike tool:

https://github.com/RRZE-HPC/OSACA

It would be nice to see something with a more open and responsive development process compared to IACA.

No, this is a different IACA-like tool. Our tool is not public yet.

Oh cool, seems like we'll jump from zero to two direct competitors to IACA soon. I look forward to your tool (hopefully it can use the same IACA marker bytes so binaries and be compiled once for all these tools).

Yes, it will use the same marker bytes.

There is also llvm-mca, which is kinda neat since it uses the I formation that LLVM has about the op cost. Contrasting that to IACA or OACA is valuable as well.

What about Google Exegesis project? They also infer instruction latency.

https://github.com/google/EXEgesis

You are right, I had forgotten about that one. Do they actually provide results for various CPUs in human-readable form anywhere, or is it only a toolset for generating the benchmarks and collecting the results locally (plus PDF extraction to process the Intel SDM)?

I think they have internally tools for humans but the open source project only produces the machine-readable information intended to be consumed by compilers. If you look at their slide deck they have some kind of visualizer that explains dependency and port dispatch for a short snippet of asm.

Yeah I wasn't talking so much about machine vs human readable, but whether the results for various CPUs are available, published somewhere in the git repo or elsewhere. If not, then it's just a tool for getting the results yourself, on hardware you have - which is also very nice, but a different type of resource as compared to Agner's published guides for 20+ CPUs, and the uops.info tables, etc.

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