This adds full back-end support for the Fence, AtomicLoad
and AtomicStore operations, and partial support for the
AtomicCas and AtomicRmw operations.
The missing pieces include sub-word operations, operations
on little-endian memory requiring byte-swapping, and some
of the subtypes of AtomicRmw -- everything that cannot be
implemented without a compare-and-swap loop. This will be
done in a follow-up patch.
This patch already suffices to make the test suite green
again after a recent change that now requires atomic
operations when accessing the heap.
* Add support for x64 packed promote low
* Add support for x64 packed floating point demote
* Update vector promote low and demote by adding constraints
Also does some renaming and minor refactoring
cranelift-codegen's build failed on s390x, with this error:
```
error[E0432]: unresolved import `crate::isa::unwind::systemv`
--> cranelift/codegen/src/isa/s390x/mod.rs:6:25
|
6 | use crate::isa::unwind::systemv::RegisterMappingError;
| ^^^^^^^ could not find `systemv` in `unwind`
```
This import should be used only with `unwind` feature enabled.
This is sometimes useful when performing analyses on the generated
machine code: for example, some kinds of code verifiers will want to do
a control-flow analysis, and it is much easier to do this if one does
not have to recover the CFG from the machine code (doing so requires
heavyweight analysis when indirect branches are involved). If one trusts
the control-flow lowering and only needs to verify other properties of
the code, this can be very useful.
This adds support for the IBM z/Architecture (s390x-ibm-linux).
The status of the s390x backend in its current form is:
- Wasmtime is fully functional and passes all tests on s390x.
- All back-end features supported, with the exception of SIMD.
- There is still a lot of potential for performance improvements.
- Currently the only supported processor type is z15.
