This unifies the logic around Rex prefix emission and hopefully makes REX prefix errors less likely.
There are still several instructions that use other sources to determine the flags, so set_w and clear_w are left as is.
Additional cleanups:
* Change always_emit_if_8bit_needed to take a Reg instead of a u8 for type safety.
* Deduplicated emission code in MovRM.
- Panic messages must now be string literals (we used `format!()` in
many places; `panic!()` can take format strings directly).
- Some dead enum options with EVEX encoding stuff in old x86 backend.
This will go away soon and/or be moved to the new backend anyway, so
let's silence the warning for now.
- A few other misc warnings.
the fdstat of a dirfd needs to include both the file and dir rights in
the inheriting field.
The wasi-libc path_open bases the base rights of child directories off
the inheriting rights of the parent, so if we only put file rights in
there, opening a child directory will not have any directory operations
permitted.
Fixes https://github.com/bytecodealliance/wasmtime/issues/2638
* Ensure `store` is in the function names
* Don't abort the process on `add_fuel` when fuel isn't configured
* Allow learning about failure in both `add_fuel` and `fuel_consumed`
Apparently on macOS `setjmp` manipulates the process-wide signal mask
which adds a good deal of overhead. We don't actually need this
functionality so this commit switches to using the `sig` version of
setjmp/longjmp where we can explicitly ask the signal mask to not get
preserved. This came out of poking around on #2644 and on macOS locally
thi sdropped the overhead from 721ns to 55ns.
This is in preparation for refactoring all x64::Inst arms to use OperandSize.
Current uses of OperandSize fall into two categories:
1. XMM operations which require 32/64 bit operands
2. Immediates which only care about 64-bit or not.
Adds assertions to existing Inst constructors to check that they are passed valid sizes.
This change also removes the implicit widening of 1 and 2 byte values to 4 bytes. from_bytes() is only used by category 2, so removing this behavior will not change any visible behavior.
Overall this change should be a no-op.
