The BranchTarget abstraction is no longer needed, since all branches are
being emitted using a MachLabel target. Remove BranchTarget and simply
use MachLabel everywhere a branch target is required. (This brings the
s390x back-end in line with what x64 does as well.)
In addition, simplify jumptable emission by moving all instructions
that do not depend on the internal label (i.e. the conditional branch
to the default label, as well as the scaling the index register) out of
the combined JTSequence instruction.
This refactoring will make moving branch generation to ISLE easier.
In preparing the back-end to move to ISLE, I detected a
number of codegen bugs in the existing code, which are
fixed here:
- Fix internal compiler error with uload16/icmp corner case.
- Fix broken Cls lowering.
- Correctly mask shift count for i8/i16 shifts.
In addition, I made several changes to operand encodings
in various MInst patterns. These should not have any
functional effect, but will make the ISLE migration easier:
- Encode floating-point constants as u32/u64 in MInst patterns.
- Encode shift amounts as u8 and Reg in ShiftOp pattern.
- Use MemArg in LoadMultiple64 and StoreMultiple64 patterns.
* Support full set of ADD LOGICAL / SUBTRACT LOGICAL instructions
* Full implementation of IaddIfcout lowering
* Enable most memory64 tests (except simd and threads)
Cranelift crates have historically been much more verbose with debug-level
logging than most other crates in the Rust ecosystem. We log things like how
many parameters a basic block has, the color of virtual registers during
regalloc, etc. Even for Cranelift hackers, these things are largely only useful
when hacking specifically on Cranelift and looking at a particular test case,
not even when using some Cranelift embedding (such as Wasmtime).
Most of the time, when people want logging for their Rust programs, they do
something like:
RUST_LOG=debug cargo run
This means that they get all that mostly not useful debug logging out of
Cranelift. So they might want to disable logging for Cranelift, or change it to
a higher log level:
RUST_LOG=debug,cranelift=info cargo run
The problem is that this is already more annoying to type that `RUST_LOG=debug`,
and that Cranelift isn't one single crate, so you actually have to play
whack-a-mole with naming all the Cranelift crates off the top of your head,
something more like this:
RUST_LOG=debug,cranelift=info,cranelift_codegen=info,cranelift_wasm=info,...
Therefore, we're changing most of the `debug!` logs into `trace!` logs: anything
that is very Cranelift-internal, unlikely to be useful/meaningful to the
"average" Cranelift embedder, or prints a message for each instruction visited
during a pass. On the other hand, things that just report a one line statistic
for a whole pass, for example, are left as `debug!`. The more verbose the log
messages are, the higher the bar they must clear to be `debug!` rather than
`trace!`.
* Add support for processor features (including auto-detection).
* Move base architecture set requirement back to z14.
* Add z15 feature sets and re-enable z15-specific code generation
when required features are available.
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.
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.
