Stream: git-wasmtime

Topic: wasmtime / issue #11163 Cache GC heap memory's `VMMemoryD...

Wasmtime GitHub notifications bot (Jun 30 2025 at 20:05):

fitzgen opened issue #11163:

Right now we call through a dyn RuntimeLinearMemory to get the VMMemoryDefinition every time we index into the heap, including in the tracing and decref'ing inner loop. It can only change when we grow the memory, which can only happen when the memory is taken out of the GC heap and then replaced, so we can just update the cache every time it is replaced. This should remove a bunch of indirect calls and let LLVM inline and GVN and etc more stuff.

Wasmtime GitHub notifications bot (Jun 30 2025 at 20:05):

fitzgen added the performance label to Issue #11163.

Wasmtime GitHub notifications bot (Jun 30 2025 at 20:05):

fitzgen added the wasm-proposal:gc label to Issue #11163.

Wasmtime GitHub notifications bot (Jul 01 2025 at 00:33):

fitzgen closed issue #11163:

Right now we call through a dyn RuntimeLinearMemory to get the VMMemoryDefinition every time we index into the heap, including in the tracing and decref'ing inner loop. It can only change when we grow the memory, which can only happen when the memory is taken out of the GC heap and then replaced, so we can just update the cache every time it is replaced. This should remove a bunch of indirect calls and let LLVM inline and GVN and etc more stuff.

Last updated: Dec 06 2025 at 07:03 UTC