WebAssembly Proposals Support
The following table summarizes Wasmtime's support for WebAssembly proposals as
well as the command line flag and wasmtime::Config method you can
use to enable or disable support for a proposal.
If a proposal is not listed, then it is not supported by Wasmtime.
Wasmtime will never enable a proposal by default unless it has reached phase 4 of the WebAssembly standardizations process and its implementation in Wasmtime has been thoroughly vetted.
| WebAssembly Proposal | Supported in Wasmtime? | Command Line Flag | Config Method |
|---|---|---|---|
| Import and Export Mutable Globals | Yes. Always enabled. | (none) | (none) |
| Sign-Extension Operations | Yes. Always enabled. | (none) | (none) |
| Non-Trapping Float-to-Int Conversions | Yes. Always enabled. | (none) | (none) |
| Multi-Value | Yes. Enabled by default. | --enable-multi-value | wasm_multi_value |
| Bulk Memory Operations | Yes. Enabled by default. | --enable-bulk-memory | wasm_bulk_memory |
| Reference Types | Yes. Enabled by default. | --enable-reference-types | wasm_reference_types |
| Fixed-Width SIMD | In progress. | --enable-simd | wasm_simd |
| Threads and Atomics | In progress. | --enable-threads | wasm_threads |
| Multi-Memory | Yes. | --enable-multi-memory | wasm_multi_memory |
| Module Linking | Yes. | --enable-module-linking | wasm_module_linking |
| Memory64 | Yes. | --enable-memory64 | wasm_memory64 |