Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: e40eb8adbcd7183b6a5032e325dd57f28d72c490
https://github.com/WebKit/WebKit/commit/e40eb8adbcd7183b6a5032e325dd57f28d72c490
Author: Yusuke Suzuki <[email protected]>
Date: 2026-03-27 (Fri, 27 Mar 2026)
Changed paths:
A JSTests/stress/wasm-gc-structureid-cast-optimization.js
M Source/JavaScriptCore/b3/B3AbstractHeapRepository.h
M Source/JavaScriptCore/b3/B3LowerMacros.cpp
M Source/JavaScriptCore/b3/B3ReduceStrength.cpp
M Source/JavaScriptCore/b3/B3Validate.cpp
M Source/JavaScriptCore/b3/B3Value.cpp
M Source/JavaScriptCore/b3/B3Value.h
M Source/JavaScriptCore/b3/B3ValueKey.cpp
M Source/JavaScriptCore/b3/B3ValueKey.h
M Source/JavaScriptCore/b3/B3ValueKeyInlines.h
M Source/JavaScriptCore/b3/B3WasmRefTypeCheckValue.h
M Source/JavaScriptCore/runtime/Structure.cpp
M Source/JavaScriptCore/wasm/WasmBBQJIT64.cpp
M Source/JavaScriptCore/wasm/WasmFormat.cpp
M Source/JavaScriptCore/wasm/WasmOMGIRGenerator.cpp
M Source/JavaScriptCore/wasm/WasmTypeDefinition.cpp
M Source/JavaScriptCore/wasm/js/JSWebAssemblyArray.h
M Source/JavaScriptCore/wasm/js/WebAssemblyGCObjectBase.cpp
M Source/JavaScriptCore/wasm/js/WebAssemblyGCObjectBase.h
M Source/JavaScriptCore/wasm/js/WebAssemblyGCStructure.cpp
M Source/JavaScriptCore/wasm/js/WebAssemblyGCStructure.h
Log Message:
-----------
[JSC] Reduce size of Wasm GC objects by dropping m_rtt
https://bugs.webkit.org/show_bug.cgi?id=310881
rdar://173493466
Reviewed by Keith Miller.
This patch reduces Wasm GC object size by removing m_rtt. The key is
that now these objects are realm-less: so Structure is unique to m_rtt.
We use StructureID for type checking instead of embedded m_rtt.
To keep the original m_rtt's faster checking,
1. We re-introduce cached type display in WebAssemblyGCStructure. But
this time, we cache StructureID (4 bytes) instead of RTT* (8 bytes).
And using StructureID comparison for most of type checks.
2. If the type depth is deeper than cached display size (6), then
retrieving RTT* from Structure and uses the previous code.
* JSTests/stress/wasm-gc-structureid-cast-optimization.js: Added.
(uleb128):
(sleb128):
(encodeSection):
(encodeString):
(buildModule.encodeBody):
(buildModule):
(main):
* Source/JavaScriptCore/b3/B3AbstractHeapRepository.h:
* Source/JavaScriptCore/b3/B3LowerMacros.cpp:
* Source/JavaScriptCore/b3/B3ReduceStrength.cpp:
* Source/JavaScriptCore/b3/B3Validate.cpp:
* Source/JavaScriptCore/b3/B3Value.cpp:
(JSC::B3::Value::key const):
* Source/JavaScriptCore/b3/B3Value.h:
* Source/JavaScriptCore/b3/B3ValueKey.cpp:
(JSC::B3::ValueKey::materialize const):
* Source/JavaScriptCore/b3/B3ValueKey.h:
* Source/JavaScriptCore/b3/B3ValueKeyInlines.h:
(JSC::B3::ValueKey::ValueKey):
* Source/JavaScriptCore/b3/B3WasmRefTypeCheckValue.h:
* Source/JavaScriptCore/runtime/Structure.cpp:
(JSC::Structure::visitChildrenImpl):
* Source/JavaScriptCore/wasm/WasmBBQJIT64.cpp:
(JSC::Wasm::BBQJITImpl::BBQJIT::emitAllocateGCArrayUninitialized):
(JSC::Wasm::BBQJITImpl::BBQJIT::emitAllocateGCStructUninitialized):
(JSC::Wasm::BBQJITImpl::BBQJIT::emitRefTestOrCast):
* Source/JavaScriptCore/wasm/WasmFormat.cpp:
(JSC::Wasm::validateWasmValue):
* Source/JavaScriptCore/wasm/WasmOMGIRGenerator.cpp:
(JSC::Wasm::OMGIRGenerator::emitRefTestOrCast):
(JSC::Wasm::OMGIRGenerator::allocateWasmGCObject):
(JSC::Wasm::OMGIRGenerator::allocateWasmGCArrayUninitialized):
* Source/JavaScriptCore/wasm/WasmTypeDefinition.cpp:
(JSC::Wasm::TypeInformation::isReferenceValueAssignable):
* Source/JavaScriptCore/wasm/js/JSWebAssemblyArray.h:
* Source/JavaScriptCore/wasm/js/WebAssemblyGCObjectBase.cpp:
(JSC::WebAssemblyGCObjectBase::WebAssemblyGCObjectBase):
* Source/JavaScriptCore/wasm/js/WebAssemblyGCObjectBase.h:
(JSC::WebAssemblyGCObjectBase::rtt const):
(JSC::WebAssemblyGCObjectBase::offsetOfRTT): Deleted.
* Source/JavaScriptCore/wasm/js/WebAssemblyGCStructure.cpp:
(JSC::WebAssemblyGCStructure::finishCreation):
(JSC::WebAssemblyGCStructure::visitAdditionalChildren):
* Source/JavaScriptCore/wasm/js/WebAssemblyGCStructure.h:
Canonical link: https://commits.webkit.org/310119@main
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