dev call 20240111

Dev Call: 11 January 2024

Present

Stepan, Florian, Simon, Petr, Du Toit, Tim, Matti, Antonio

Cython/HPy

• Du Toit's internship is ending in January.
• Du Toit and Florian are currently concentrating on benchmarks.
  • hpy_forloop
  • hpy_fannkuch
  • hpy_coverage
  • hpy_fibonacci
• There are still performance problems that need to be addressed but preliminary numbers are very good.
• E.g. for hpy_forloop
  • For CPython, numbers are within the expected slow down of 5% (HPy Hybrid ABI vs. pure C API).
  • For GraalPy, we've seen impressive speedups of up to 50x (HPy Hybrid ABI vs. pure C API) and we can get
• hpy_fibonacci is still suffering from a missing shortcut. Cython is bypassing the generic Python call if the called object is a cython_function_or_method and would fish out the vectorcallfunc and call that directly. We think we could do a similar shortcut in HPy by using __pyx_CyFunctionObject_AsStruct and also call the appropriate C function directly.
• Calling the C call function of CyFunction directly may be related to the work happening in a PyPy branch. In this branch, PyPy tries to directly call C functions by leveraging argument clinic type information. This is the work of Max Bernstein.
• Matti asks to also run the benchmarks with latest PyPy (should be 7.3.14) if possible. At least hpy_forloop should work since we didn't need any HPy additions for it.

Python C API

• Draft PEP for Python C API guidelines is there; Petr will review it with a clear head and then publish it.
• The C API Working Group is discussing a bunch of new C API functions.
• Nothing much happened on NI.

C API Conference Workshop

• Antonio did not create the list yet but will
• The idea is to have a rather informal workshop with lightning talks. Everyone is free to present but we should ensure that some people do have presentations prepared to get started.
• We should ask EuroPython orgranizers early and if we don't get enough people to participate, we can cancel the event.
• Stepan brought up the idea, that Petr should act as organizer; not doing the work but just to avoid that people are not interested because it looks like an HPy-only event.

NumPy/HPy

• There is still this remaining problem when calling array_iter (see Issue 19).