Regression: explicit TCO and Fat LTO jump table size explosion with inline
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C-bug
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needs-triage
regression-untriaged
- Dominant language
- Rust
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- 119k
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Description
On fat LTO, it seems like the jump table generation is not taken in effect, or rather taken too literally.
For thin LTO however, did seems to work.
Reported as of https://github.com/explodingcamera/tinywasm/pull/55#issuecomment-5493370260
rustc version: nightly 1.100.0
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the tinywasm scenario referenced in PR #55 with nightly rustc 1.100.0, comparing fat LTO and thin LTO builds. Trace the jump-table generation path and establish the expected table size; done means fat LTO no longer causes the reported size explosion while thin LTO behavior remains intact.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Active
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100