[wasm][coreclr] Fix reflection with large valuetypes #123759
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I am also writing down my thoughts on #120791 and will add them soon |
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Tagging subscribers to this area: @mangod9 |
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Pull request overview
This PR updates the WASM/CoreCLR interpreter calling convention support so reflection invoke can correctly pass/return large value types (notably SIMD vectors), including adjusting the special-argument ordering (retbuf vs this) and improving stack layout alignment.
Changes:
- Adjust WASM reflection invoke/call-descriptor plumbing to account for retbuf presence and interpreter stack-slot sizing.
- Update ArgIterator WASM logic for special-arg offsets and value-type alignment handling.
- Fix a test failure message to correctly reference
Vector128<T>.
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| src/tests/JIT/Directed/VectorABI/VectorMgdMgdArray.cs | Updates failure message text to reflect Vector128<T> checks. |
| src/coreclr/vm/wasm/cgencpu.h | Refines return-type size macros used by calling convention logic. |
| src/coreclr/vm/wasm/calldescrworkerwasm.cpp | Adjusts interpreter call argument pointer/size handling when a retbuf is present. |
| src/coreclr/vm/reflectioninvocation.cpp | Updates stack-slot counting and records retbuf presence for WASM reflection calls. |
| src/coreclr/vm/frames.cpp | Recomputes this offset via ArgIterator instance (signature-aware). |
| src/coreclr/vm/callingconvention.h | Makes GetThisOffset instance-based; updates WASM special-arg ordering and adds valuetype alignment logic. |
| src/coreclr/vm/callhelpers.h | Adds hasRetBuff field (WASM-only) to CallDescrData. |
| src/coreclr/vm/callhelpers.cpp | Initializes hasRetBuff for WASM call paths and adds a debug assert. |
Co-authored-by: Copilot <[email protected]>
jkotas
reviewed
Jan 29, 2026
This was referenced Jan 30, 2026
Open
jkotas
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Jan 30, 2026
| ## Incoming argument ABI | ||
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| The linear stack pointer `$sp` is the first argument to all methods. At a native->managed transition it is the value of the `$__stack_pointer` global. This global may be updated to the current `$sp` within managed code, and must be up to date with the current `$sp` at managed->native boundaries. Within the method the stack pointer always points at the bottom (lowest address) of the stack; generally this is a fixed offset from the value the stack pointer held on entry, except in methods that can do dynamic allocation. | ||
| The linear stack pointer `$sp` is the first argument after the managed `this` argument or the first argument for static methods. At a native->managed transition it is the value of the `$__stack_pointer` global. This global may be updated to the current `$sp` within managed code, and must be up to date with the current `$sp` at managed->native boundaries. Within the method the stack pointer always points at the bottom (lowest address) of the stack; generally this is a fixed offset from the value the stack pointer held on entry, except in methods that can do dynamic allocation. |
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I think it would be better for stack pointer to be argument 0 so that it is always in a fixed position, and for this to be to after that (if it is present) so that it is in fixed position too.
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Implement return of large valuetypes from reflection calls and also large valuetypes arguments.
Change the order of
thisandretbufarguments. This goes toward the #120791 and the new calling convention. It also helps to keep the interpreter calls use simple memory copy.JIT/Directed/Directed_3 runtime tests were used as repro.
Fixes #122922