JuliaDiff / JuliaDiff/ChainRules.jl
BLAS.gemm and BLAS.gemv pullbacks are type-unstable
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- Dominant language
- Julia
- Stars
- 475
- Forks
- 98
- PR merge metrics
- No merged PRs in 30d
Description
As identified by https://github.com/JuliaDiff/ChainRulesTestUtils.jl/pull/78, the pullbacks for BLAS.gemm and BLAS.gemv are type-unstable because a different InplaceableThunk is returned based on the value of the input parameters. For the norm functions, I worked around this by pushing the condition check to within the thunk, which in this case looks like it will produce a lot of duplicate code. Do we expect that this type-instability to cause decreased efficiency?
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First steps
- Read the whole issue, then the project's contributing guide.
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- Open a pull request that references the issue number.
Research direction
The issue identifies the pullbacks for BLAS.gemm and BLAS.gemv as the affected entry points; inspect their definitions and the value-dependent InplaceableThunk paths. Confirm whether the return type varies and assess the efficiency impact before deciding whether a thunk-local condition is appropriate.
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Assessment
- Tech stack
- julia
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100