python / python/cpython

JIT stencil generation for i686-pc-windows-msvc has issues with SSE

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#146,365 3 comments 0 reactions 0 assignees View on GitHub

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build OS-windows topic-JIT type-bug
Dominant language
Python
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Description

Bug report

Bug description:

When working on adding float operations in #146307 the bytecode generation the CI failed for only the [i686-pc-windows-msvc] build. Link to failing CI:

i686-pc-windows-msvc

We can make the CI run by adding the -mno-sse flags:

https://github.com/python/cpython/pull/146307/changes/8559fb8b057364cdb20790380ac871e5100c9e12

Ideally we should not have to disable SSE at this might hurt performance.

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the failing i686-pc-windows-msvc CI job and the changes in PR #146307, then trace the JIT stencil bytecode generation involved in the float operations. Determine why the build needs -mno-sse and verify the fix by rerunning the affected CI build without disabling SSE.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Needs clarification
Newbie friendliness
35/100

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