This patch adds support for parsing structs in the type section.
It also removes the assumption that all types in the type section are
function types, adding appropriate validation.
Spec tests struct.3 and struct.4 have been disable as this would
require expanding `ValueType` to include more heap-types.
Instead of trying to indirectly load 2x64 bits from *cc, load addresses
directly from their own contiguous allocation.
This allows a future optimisation where we defer loading addresses to
reduce memory port pressure.
In our process architecture, there's only ever one JS::VM per process.
This allows us to have a VM::the() singleton getter that optimizes
down to a single global access everywhere.
Seeing 1-2% speed-up on all JS benchmarks from this.
This can be done by passing
`--export-js <module>.<fn>[(<arg>:type, ...)][:type]=<source>`,
which uses a js function `(arg...) => source` to resolve the requested
import `module::fn`.
All literal wasm value types (i<n> and v128) are supported as both
parameter and return types.
This still passes the values on the stack, but registers are now allowed
to cross a call boundary.
This is a very significant (>50%) improvement on the small call
microbenchmarks on my machine.
This commit adds a register allocator, with 8 available "register"
slots.
In testing with various random blobs, this moves anywhere from 30% to
74% of value accesses into predefined slots, and is about a ~20% perf
increase end-to-end.
To actually make this usable, a few structural changes were also made:
- we no longer do one instruction per interpret call
- trapping is an (unlikely) exit condition
- the label and frame stacks are replaced with linked lists with a huge
node cache size, as we only need to touch the last element and
push/pop is very frequent.
This is largely unused (only in wasm.cpp)
A future reimplementation can bring it back as a separate interpreter
class that embeds the current bytecode interpreter.
...instead of specially handling JS::Completion.
This makes it possible for LibWeb/LibJS to have full control over how
these things are made, stored, and visited (whenever).
Fixes an issue where we couldn't roundtrip a JS exception through Wasm.
