193551a8d6
* Optimize `table.init` instruction and instantiation This commit optimizes table initialization as part of instance instantiation and also applies the same optimization to the `table.init` instruction. One part of this commit is to remove some preexisting duplication between instance instantiation and the `table.init` instruction itself, after this the actual implementation of `table.init` is optimized to effectively have fewer bounds checks in fewer places and have a much tighter loop for instantiation. A big fallout from this change is that memory/table initializer offsets are now stored as `u32` instead of `usize` to remove a few casts in a few places. This ended up requiring moving some overflow checks that happened in parsing to later in code itself because otherwise the wrong spec test errors are emitted during testing. I've tried to trace where these can possibly overflow but I think that I managed to get everything. In a local synthetic test where an empty module with a single 80,000 element initializer this improves total instantiation time by 4x (562us => 141us) * Review comments
This is the wasmtime-environ crate, which contains the implementations
of the ModuleEnvironment and FuncEnvironment traits from
cranelift-wasm. They effectively
implement an ABI for basic wasm compilation that defines how linear memories
are allocated, how indirect calls work, and other details. They can be used
for JITing, native object files, or other purposes.