[PGO] Provide Pre-Generated Profiles

[ptr1337]

Feature or enhancement

PGO (Profile-Guided Optimization) offers significant performance benefits for Python. However, the current approach has a drawback: it makes the builds non-reproducible.

This issue could be resolved if upstream provided pre-generated profiles (perhaps via CI pipelines). These profiles could then be included in the distributed tarball, similar to how Chromium handles it. By doing so, distributions wouldn't need to:

1. Compile the source code twice.
2. Perform profiling themselves.
   In addition to streamlining the process for maintainers, this would also help maintain package reproducibility—a key consideration for many distributions.

I am not sure, about the integration with GCC, since in my testing the compilation failed with a preset profile (but I didnt dig deeper into this yet.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

[ptr1337]

I have tested reusing the profile from a clang build, and this worked well.
I did not benchmark it yet - there were some profile mismatches, but I think this should be generally not that heavy.

Distributions like Fedora/Archlinux would be very interested in having this feature properly implemented.