JIT: Fix loop cloning with nested EH regions - #133790
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When placing the slow-loop preheader, the loop's lexically bottommost block may lie in a nested EH region. So instead, use the fast-loop preheader for placement, as it belongs to the correct region. Fixes #133758 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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@EgorBo ptal No diffs, simple change. |
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Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch |
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Pull request overview
Fixes JIT loop cloning when the loop’s lexical bottom is inside a nested EH region.
Changes:
- Uses the fast-loop preheader for valid slow-preheader placement.
- Adds a nested-EH regression test.
File summaries
| File | Summary |
|---|---|
src/coreclr/jit/loopcloning.cpp |
Corrects slow-preheader placement. |
src/tests/JIT/opt/Cloning/loops_with_eh.cs |
Adds nested-EH regression coverage. |
Review details
- Files reviewed: 2/2 changed files
- Comments generated: 0
- Review effort level: Lite
EgorBo
approved these changes
Sep 12, 2026
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Failures look like #133798 but with different error symptom. |
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/ba-g known mono test errors |
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When placing the slow-loop preheader, the loop's lexically bottommost block
may lie in a nested EH region. So instead, use the fast-loop preheader for
placement, as it belongs to the correct region.
Fixes #133758
Note
This pull request description was generated by GitHub Copilot.