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[WebAssembly] Enable multivalue and reference-types in generic CPU config #80923

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Merged
merged 10 commits into from
Apr 29, 2024
Merged

[WebAssembly] Enable multivalue and reference-types in generic CPU config #80923

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d6fd487
[WebAssembly] Add more features to generic CPU config
aheejin Feb 6, 2024
e501363
Merge branch 'main' into enable_features
aheejin Feb 7, 2024
01ac8bd
Mention that ABI is not turned on
aheejin Feb 23, 2024
7119137
Merge branch 'main' into enable_features
aheejin Feb 23, 2024
17e81e3
Merge branch 'main' into enable_features
aheejin Feb 23, 2024
26caed5
Merge branch 'main' into enable_features
aheejin Apr 23, 2024
de6aa6a
Enable only multivalue and reference types
aheejin Apr 23, 2024
91df749
Enable multivalue and reference-types in bleeding-edge
aheejin Apr 23, 2024
f4aee60
Update clang/docs/ReleaseNotes.rst
aheejin Apr 24, 2024
af79d4e
Merge branch 'main' into enable_features
aheejin Apr 24, 2024
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5 changes: 5 additions & 0 deletions clang/docs/ReleaseNotes.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -668,6 +668,11 @@ AIX Support
WebAssembly Support
^^^^^^^^^^^^^^^^^^^

The -mcpu=generic configuration now enables multivalue and reference-types.These
proposals are standardized and available in all major engines. Enabling
multivalue here only enables the language feature but does not turn on the
multivalue ABI.

AVR Support
^^^^^^^^^^^

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20 changes: 13 additions & 7 deletions clang/lib/Basic/Targets/WebAssembly.cpp
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Expand Up @@ -147,19 +147,25 @@ void WebAssemblyTargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
bool WebAssemblyTargetInfo::initFeatureMap(
llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
const std::vector<std::string> &FeaturesVec) const {
if (CPU == "bleeding-edge") {
Features["nontrapping-fptoint"] = true;
auto addGenericFeatures = [&]() {
Features["sign-ext"] = true;
Features["mutable-globals"] = true;
Features["reference-types"] = true;
Features["multivalue"] = true;
};
auto addBleedingEdgeFeatures = [&]() {
addGenericFeatures();
Features["nontrapping-fptoint"] = true;
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@tlively tlively Apr 23, 2024

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Looks like this was enabled in Safari in September 2021. Should we enable this by default as well?

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@tlively tlively Apr 23, 2024

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Oh, I see, if we think we would need a Binaryen lowering pass first, then proceeding without this SGTM.

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@sbc100 sbc100 Apr 23, 2024

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I'm a bit sad not to see this added, since this is the one that can actually improve codegen. If we know we want to enable to this, is there any downside to doing two different rounds (i.e. are there advantages to waiting on this until we have the lowering pass in place?)

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@dschuff dschuff Apr 23, 2024 •
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MV and reftypes are required to use exnref, that's the thing that's on the critical path here. So yes, we definitely want to land these two without blocking on nontrapping-fptoint.

Relatedly (to nontrapping-fptoint, but unrelatedly to this PR), I prototyped a Binaryen pass to lower away LLVM's use of nontrapping-fptoint* which is what would allow us to improve codegen. I think it works, but I discovered that some of emscripten's tests fail when we enable nontrapping fptoint, and I haven't yet looked at why that's the case (either a bug in emscripten's tests, or a bug in V8's implementation of nontrapping fptoint). We'd need to also fix that to unblock enabling this.

** (This isn't exactly the same as a full lowering of nontrapping-fptoint as spec'ed, because it takes advantage of knowledge of the semantics of LLVM's fptosi intrinsics)

Features["bulk-memory"] = true;
Features["atomics"] = true;
Features["mutable-globals"] = true;
Features["tail-call"] = true;
Features["reference-types"] = true;
Features["multimemory"] = true;
setSIMDLevel(Features, SIMD128, true);
} else if (CPU == "generic") {
Features["sign-ext"] = true;
Features["mutable-globals"] = true;
};
if (CPU == "generic") {
addGenericFeatures();
} else if (CPU == "bleeding-edge") {
addBleedingEdgeFeatures();
}

return TargetInfo::initFeatureMap(Features, Diags, CPU, FeaturesVec);
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7 changes: 4 additions & 3 deletions clang/test/Preprocessor/wasm-target-features.c
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Expand Up @@ -155,15 +155,15 @@
//
// GENERIC-DAG:#define __wasm_sign_ext__ 1{{$}}
// GENERIC-DAG:#define __wasm_mutable_globals__ 1{{$}}
// GENERIC-DAG:#define __wasm_multivalue__ 1{{$}}
// GENERIC-DAG:#define __wasm_reference_types__ 1{{$}}
// GENERIC-NOT:#define __wasm_nontrapping_fptoint__ 1{{$}}
// GENERIC-NOT:#define __wasm_bulk_memory__ 1{{$}}
// GENERIC-NOT:#define __wasm_simd128__ 1{{$}}
// GENERIC-NOT:#define __wasm_atomics__ 1{{$}}
// GENERIC-NOT:#define __wasm_tail_call__ 1{{$}}
// GENERIC-NOT:#define __wasm_multimemory__ 1{{$}}
// GENERIC-NOT:#define __wasm_exception_handling__ 1{{$}}
// GENERIC-NOT:#define __wasm_multivalue__ 1{{$}}
// GENERIC-NOT:#define __wasm_reference_types__ 1{{$}}
// GENERIC-NOT:#define __wasm_extended_const__ 1{{$}}

// RUN: %clang -E -dM %s -o - 2>&1 \
Expand All @@ -181,9 +181,10 @@
// BLEEDING-EDGE-DAG:#define __wasm_mutable_globals__ 1{{$}}
// BLEEDING-EDGE-DAG:#define __wasm_tail_call__ 1{{$}}
// BLEEDING-EDGE-DAG:#define __wasm_multimemory__ 1{{$}}
// BLEEDING-EDGE-DAG:#define __wasm_multivalue__ 1{{$}}
// BLEEDING-EDGE-DAG:#define __wasm_reference_types__ 1{{$}}
// BLEEDING-EDGE-NOT:#define __wasm_exception_handling__ 1{{$}}
// BLEEDING-EDGE-NOT:#define __wasm_multivalue__ 1{{$}}
// BLEEDING-EDGE-NOT:#define __wasm_reference_types__ 1{{$}}
// BLEEDING-EDGE-NOT:#define __wasm_extended_const__ 1{{$}}
// BLEEDING-EDGE-NOT:#define __wasm_relaxed_simd__ 1{{$}}

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