Dotnet Uses Legacy Wasm Exceptions. #188
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Add a pass to the build script that replaces them with the non-legacy execptions. This doesn't seem to impact performance. The dotnet runtime still seems to generate one module/function that has a legacy exception but that function is never called. It's also somewhat degenerate since it's just `(try catch_all)` and has no other body. This doesn't seem to make a difference for the score in all CLIs and we don't want legacy exception usage in JetStream to be the thing that keeps the legacy wasm exceptions "feature" alive. Note: I didn't run the build script. I just ran the wasm-opt commands on the build products. Mostly because when I recompile the code doesn't run or is 5x slower than the previous binaries.
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| echo "Copying symbol maps..." | tee -a "$BUILD_LOG" | ||
| cp ./src/dotnet/obj/Release/net9.0/wasm/for-publish/dotnet.native.js.symbols ./build-interp/wwwroot/_framework/ | ||
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| for wasmFile in $(find "./build-interp" -type f -name "*.wasm"); |
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Could you add a comment explaining this step.
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Generally SGTM to avoid depending on legacy EH, but:
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What's the name of the function ? Or how do I find it ? |
Agreed, would be good to know this. I would also highly encourage switching to
I think it might have been a stale build artifact from a prior build. If I remove the additions to
It looks like they're roughly the same size. For
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It doesn't appear to have a name anywhere. The entire module is just which makes me think it's some kind of dynamically generated module in the interp variant of the benchmark. |
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I think we are using legacy feature detection but should be using new one |
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Oh interesting, I think the benchmark still executes legacy exceptions, at least enough to trigger a tier up to our optimizing tiers for aot. I added some logging but I don't know which module they're coming from. |
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Looking deeper into the issue. Net9 and Net10 both use Emscripten version 3.1.56, which doesn't support final EH spec. Our JetStream benchmark is compiled with Net9. I think that we would need to upgrade Emscripten to at least 4.0.0 in order to use I created dotnet/runtime#119961 for that. |
Add a pass to the build script that replaces them with the non-legacy execptions. This doesn't seem to impact performance. The dotnet runtime still seems to generate one module/function that has a legacy exception but that function is never called. It's also somewhat degenerate since it's just
(try catch_all)and has no other body.This doesn't seem to make a difference for the score in all CLIs and we don't want legacy exception usage in JetStream to be the thing that keeps the legacy wasm exceptions "feature" alive.
Note: I didn't run the build script. I just ran the wasm-opt commands on the build products. Mostly because when I recompile the code doesn't run or is 5x slower than the previous binaries.