[meta] Track SIMD experimental instructions
Categories
(Core :: JavaScript: WebAssembly, task, P2)
Tracking
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People
(Reporter: lth, Assigned: lth)
References
(Blocks 1 open bug)
Details
(Keywords: meta)
Tracker for emerging wasm SIMD instructions that have not been approved or post-mvp'd yet. (For approved bugs, see bug 1664131 and its blockers.) This comment block will be updated as new instructions are proposed and implemented in at least one compiler, and removed from here once standardized or rejected. "V8" means "all platforms" unless noted; our own compilers are broken out individually where Rabaldr is Intel+arm64 baseline, Baldr is Intel optimizing, Cranelift is arm64 optimizing.
Likely to be accepted:
- #124 Sign select - V8, LLVM, Binaryen, emscripten
- #380 Extended pairwise addition - V8 (arm64)
- #383 Double-precision conversion - all unknown
- #379 Population count - V8 (unspecified arch), LLVM, Binaryen, emscripten
Unknown:
- #372 i64x2.widen_i16x8 and i32x4.widen_i8x16 - some prototyping ongoing?
- #375 horizontal add - unclear
- #382 Extended multiply horizontal add - no traction?
- #395 Sign/Zero extension - all unknown
- #413 i64x2.abs - all unknown
Likely to be rejected or deferred:
- #414 i64x2.<compare>_s - all unknown - controversial - did not reach consensus 2021/1/22
- #412 i64x2.<compare>_u - all unknown - controversial
Assignee | ||
Comment 1•4 years ago
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V8 bug tracker with all SIMD issues: https://bugs.chromium.org/p/v8/issues/list?q=label:Proj-SIMD
Assignee | ||
Updated•4 years ago
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Assignee | ||
Comment 2•4 years ago
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Approved at the 2021-01-29 meeting:
- Extended pairwise addition (380)
- fx4x2 conversions (all six of them) (383) (although there's an attempt to rollback the trunc_sat variants?)
Close to consensus and will probably make it, but not quite there yet:
- Population count (379)
Rejected:
- Min/max (417, 418)
- Prefetch (352)
Another meeting in a week to make progress on the rest.
Assignee | ||
Comment 3•4 years ago
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There's an effort to push population count across the finish line: https://github.com/WebAssembly/simd/pull/379#issuecomment-770331917.
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Comment 4•4 years ago
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There are no more experimental instructions, the MVP instruction set is done. We'll open a new tracker for post-MVP.
Description
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