This approach is not the best but avoids an extra instruction; perhaps at some point, as mentioned in https://github.com/bytecodealliance/wasmtime/pull/2248, we will add the extra instruction or refactor things in such a way that this `Inst` variant is unnecessary.
As part of a Wasm JIT update, SpiderMonkey is changing its internal
WebAssembly function ABI. The new ABI's frame format includes "caller
TLS" and "callee TLS" slots. The details of where these come from are
not important; from Cranelift's point of view, the only relevant
requirement is that we have two on-stack args that are always present
(offsetting other on-stack args), and that we define special argument
purposes so that we can supply values for these slots.
Note that this adds a *new* ABI (a variant of the Baldrdash ABI) because
we do not want to tightly couple the landing of this PR to the landing
of the changes in SpiderMonkey; it's better if both the old and new
behavior remain available in Cranelift, so SpiderMonkey can continue to
vendor Cranelift even if it does not land (or backs out) the ABI change.
Furthermore, note that this needs to be a Cranelift-level change (i.e.
cannot be done purely from the translator environment implementation)
because the special TLS arguments must always go on the stack, which
would not otherwise happen with the usual argument-placement logic; and
there is no primitive to push a value directly in CLIF code (the notion
of a stack frame is a lower-level concept).
This adds a new feature experimental_x64 for CLIF tests.
A test is run in the new x64 backend iff:
- either the test doesn't have an x86_64 target requirement, signaling
it must be target agnostic or not run on this target.
- or the test does require the x86_64 target, and the test is marked
with the `experimental_x64` feature.
This required one workaround in the parser. The reason is that the
parser will try to use information not provided by the TargetIsa adapter
for the Mach backends, like register names. In particular, parsing test
may fail before the test runner realizes that the test must not be run.
In this case, we early return an almost-empty TestFile from the parser,
under the same conditions as above, so that the caller may filter out
the test properly.
This also copies two tests from the test suite using the new backend,
for demonstration purposes.
This commit adds arm32 code generation for some IR insts.
Floating-point instructions are not supported, because regalloc
does not allow to represent overlapping register classes,
which are needed by VFP/Neon.
There is also no support for big-endianness, I64 and I128 types.
* clif-util: do not convert `anyhow::Error`s into strings into `anyhow::Error`s
* filetests: Use the debug formatting of `anyhow::Error`s
This provides the full error context, not just the source error's message.
This is a close analogue to bnjbvr@'s fix in commit 518b7a7e. Similar to
that fix, this PR fixes a bug in which the Wasm translator could
misalign its value stack and either mistranslate or cause a panic with a
type-checking error.
Found via fuzzing by :decoder in SpiderMonkey (bug 1664453).
This allows for more flexibility of when/where to harvest LHS candidates. For
example, we could choose to harvest candidates that overlap with and supercede
our current preopt peepholes.
This commit also makes sure that we compute the CFG before running preopt, when
harvesting LHS candidates via `clif-util souper-harvest`.
