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Build with PGO needlesly generates JIT stencils twice (and prevents usage of prebuilt stencils) #141808
Description
Bug report
Bug description:
Based on https://discuss.python.org/t/building-the-jit-with-pre-built-stencils/91838/12 I open this issue to have an issue number to reference in an upcoming PR.
When a build with PGO optimizations is used, the JIT stencils are generated, then deleted, and then generated again. The generated JIT stencils are bit-by-bit identical to each other, so I believe there is no need to delete them mid-build. Not deleting them is also a prerequisite for Fedora to be able to use pre-built JIT stencils on platforms without the required LLVM version.
CPython versions tested on:
3.15, CPython main branch
Operating systems tested on:
Linux
Linked PRs
- gh-141808: Don't remove the JIT stencils when building with PGO #141809
- GH-141808: Do not generate the jit stencils twice in case of PGO builds on Windows. #142043
- [3.14] GH-141808: Do not generate the jit stencils twice in case of PGO builds on Windows. (GH-142043) #142100
- [3.14] gh-141808: Don't remove the JIT stencils when building with PGO (GH-141809) #142657
- [3.13] gh-141808: Don't remove the JIT stencils when building with PGO (GH-141809) (GH-142657) #142955
Activity
hroncok commentedon Nov 20, 2025
I am testing if I can move the removal from
make clean-retain-profiletomake clean.EDIT: That's not enough.
pythongh-141808: Don't remove the JIT stencils when building with PGO
chris-eibl commentedon Nov 28, 2025
Like written in https://discuss.python.org/t/building-the-jit-with-pre-built-stencils/91838/14, this happens on Windows, too.
The fix is IMHO simple, see #142043.
GH-141808: Do not generate the jit stencils twice in case of PGO buil…
pythonGH-141808: Do not generate the jit stencils twice in case of PG…
[3.14] GH-141808: Do not generate the jit stencils twice in case of P…
pythonGH-141808: Do not generate the jit stencils twice in case of PG…
gh-141808: Don't remove the JIT stencils when building with PGO (#141809
[3.14] pythongh-141808: Don't remove the JIT stencils when building w…
[3.14] gh-141808: Don't remove the JIT stencils when building with PGO (
[3.13] gh-141808: Don't remove the JIT stencils when building with PGO (