[wasm] Bail R2R for all SIMD parameter sizes, not just SIMD16 - #130391
#130391Merged
lewing merged 1 commit intoJul 9, 2026
dotnet:maindotnet/runtime:mainfrom
lewing:lewing-wasm-simd8-param-baillewing/runtime:lewing-wasm-simd8-param-bailCopy head branch name to clipboard
Merged
[wasm] Bail R2R for all SIMD parameter sizes, not just SIMD16#130391lewing merged 1 commit intodotnet:maindotnet/runtime:mainfrom lewing:lewing-wasm-simd8-param-baillewing/runtime:lewing-wasm-simd8-param-bailCopy head branch name to clipboard
lewing merged 1 commit into
dotnet:maindotnet/runtime:mainfrom
lewing:lewing-wasm-simd8-param-baillewing/runtime:lewing-wasm-simd8-param-bailCopy head branch name to clipboard
Conversation
Vector2 (TYP_SIMD8) and Vector3 (TYP_SIMD12) parameters are lowered to
i32 in the wasm signature, the same as Vector128 (TYP_SIMD16), but the
argument-spill prolog only bailed R2R for TYP_SIMD16. As a result a
method with an 8-byte SIMD parameter (e.g. System.Numerics.Matrix3x2
.CreateRotation(float, Vector2)) emitted an f64.store fed by the i32
parameter local, producing an invalid module that fails wasm
validation ("type mismatch: expected f64, found i32").
Broaden the parameter bail in genBeginFnProlog from `== TYP_SIMD16` to
`varTypeIsSIMD(...)` so SIMD8/SIMD12/SIMD16 parameters are all sent to
the interpreter until SIMD parameters are supported in the wasm calling
convention. This is a follow-up to the SIMD16 bail added in dotnet#130101 and
lets System.Private.CoreLib produce a valid R2R image.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Contributor
|
Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch |
Contributor
There was a problem hiding this comment.
Pull request overview
This PR updates the WASM JIT’s R2R-bail logic to treat all SIMD-typed parameters (e.g., TYP_SIMD8/TYP_SIMD12/TYP_SIMD16) as unsupported for WASM ReadyToRun codegen, ensuring crossgen2 doesn’t emit invalid WASM modules when such parameters are present.
Changes:
- Broadened the prolog check from
TypeGet() == TYP_SIMD16tovarTypeIsSIMD(TypeGet()), so any SIMD parameter triggersNYI_WASM_SIMD(...). - Updated the associated comment and NYI message to reflect the generalized “SIMD parameter” behavior.
AndyAyersMS
approved these changes
Jul 9, 2026
AndyAyersMS
left a comment
Member
There was a problem hiding this comment.
Hopefully we get ABI support for SIMD types soon.
lewing
enabled auto-merge (squash)
July 9, 2026 01:54
Open
3 tasks
Member
Author
|
/ba-g x64 timeouts are not related to wasm only change |
eiriktsarpalis
pushed a commit
that referenced
this pull request
Jul 15, 2026
Vector2 (`TYP_SIMD8`) and Vector3 (`TYP_SIMD12`) parameters are lowered to `i32` in the wasm signature, the same as Vector128 (`TYP_SIMD16`), but the argument-spill prolog in `genBeginFnProlog` only bailed R2R for `TYP_SIMD16`. As a result, a method with an 8-byte SIMD parameter — e.g. `System.Numerics.Matrix3x2.CreateRotation(float, Vector2)` — emitted an `f64.store` fed by the `i32` parameter local, producing an invalid module that fails wasm validation: ``` func 20691 failed to validate type mismatch: expected f64, found i32 ``` This currently prevents `System.Private.CoreLib` from producing a valid R2R image (both single-file and composite). ## Fix Broaden the parameter bail from `== TYP_SIMD16` to `varTypeIsSIMD(...)` so `SIMD8`/`SIMD12`/`SIMD16` parameters are all sent to the interpreter until SIMD parameters are supported in the wasm calling convention. This is a direct follow-up to the SIMD16 parameter bail added in #130101 ("Fix a few missing SIMD bail outs that prevent SPC from validating") — it was the same class of bug, just missed for the smaller SIMD sizes. ## Validation With this change, crossgen2 `--targetos wasi --targetarch wasm` on `System.Private.CoreLib` (and a composite including it) produces a module that passes `wasm-tools validate --features all`. Verified locally on macOS/arm64. > [!NOTE] > This change was authored with the assistance of GitHub Copilot. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Vector2 (
TYP_SIMD8) and Vector3 (TYP_SIMD12) parameters are lowered toi32in the wasm signature, the same as Vector128 (TYP_SIMD16), but the argument-spill prolog ingenBeginFnPrologonly bailed R2R forTYP_SIMD16.As a result, a method with an 8-byte SIMD parameter — e.g.
System.Numerics.Matrix3x2.CreateRotation(float, Vector2)— emitted anf64.storefed by thei32parameter local, producing an invalid module that fails wasm validation:This currently prevents
System.Private.CoreLibfrom producing a valid R2R image (both single-file and composite).Fix
Broaden the parameter bail from
== TYP_SIMD16tovarTypeIsSIMD(...)soSIMD8/SIMD12/SIMD16parameters are all sent to the interpreter until SIMD parameters are supported in the wasm calling convention.This is a direct follow-up to the SIMD16 parameter bail added in #130101 ("Fix a few missing SIMD bail outs that prevent SPC from validating") — it was the same class of bug, just missed for the smaller SIMD sizes.
Validation
With this change, crossgen2
--targetos wasi --targetarch wasmonSystem.Private.CoreLib(and a composite including it) produces a module that passeswasm-tools validate --features all. Verified locally on macOS/arm64.Note
This change was authored with the assistance of GitHub Copilot.