8c5f59c0cf
These instructions have fast, inline JIT paths for the common cases, and only
call out to host VM functions for the slow paths. This required some changes to
`cranelift-wasm`'s `FuncEnvironment`: instead of taking a `FuncCursor` to insert
an instruction sequence within the current basic block,
`FuncEnvironment::translate_table_{get,set}` now take a `&mut FunctionBuilder`
so that they can create whole new basic blocks. This is necessary for
implementing GC read/write barriers that involve branching (e.g. checking for
null, or whether a store buffer is at capacity).
Furthermore, it required that the `load`, `load_complex`, and `store`
instructions handle loading and storing through an `r{32,64}` rather than just
`i{32,64}` addresses. This involved making `r{32,64}` types acceptable
instantiations of the `iAddr` type variable, plus a few new instruction
encodings.
Part of #929
This is the wasmtime-runtime crate, which contains wasm runtime library
support, supporting the wasm ABI used by wasmtime-environ,
wasmtime-jit, and wasmtime-obj.
This crate does not make a host vs. target distinction; it is meant to be compiled for the target.
Most users will want to use the main wasmtime crate instead of using this
crate directly.