Most of these optimizations are in the egraph `cprop.isle` rules now,
making a separate crate unnecessary.
Also I think the `udiv` optimizations here are straight-up wrong (doing
signed instead of unsigned division, and panicking instead of preserving
traps on division by zero) so I'm guessing this crate isn't seriously
used anywhere.
At the least, bjorn3 confirms that cg_clif doesn't use this, and I've
verified that Wasmtime doesn't either.
Closes#1090.
* Adding in the foundations for Winch `filetests`
This commit adds two new crates into the Winch workspace:
`filetests` and `test-macros`. The intent is to mimic the
structure of Cranelift `filetests`, but in a simpler way.
* Updates to documentation
This commits adds a high level document to outline how to test Winch
through the `winch-tools` utility. It also updates some inline
documentation which gets propagated to the CLI.
* Updating test-macro to use a glob instead of only a flat directory
This adds support for `.wat` tests in `cranelift-filetest`. The test runner
translates the WAT to Wasm and then uses `cranelift-wasm` to translate the Wasm
to CLIF.
These tests are always precise output tests. The test expectations can be
updated by running tests with the `CRANELIFT_TEST_BLESS=1` environment variable
set, similar to our compile precise output tests. The test's expected output is
contained in the last comment in the test file.
The tests allow for configuring the kinds of heaps used to implement Wasm linear
memory via TOML in a `;;!` comment at the start of the test.
To get ISA and Cranelift flags parsing available in the filetests crate, I had
to move the `parse_sets_and_triple` helper from the `cranelift-tools` binary
crate to the `cranelift-reader` crate, where I think it logically
fits.
Additionally, I had to make some more bits of `cranelift-wasm`'s dummy
environment `pub` so that I could properly wrap and compose it with the
environment used for the `.wat` tests. I don't think this is a big deal, but if
we eventually want to clean this stuff up, we can probably remove the dummy
environments completely, remove `translate_module`, and fold them into these new
test environments and test runner (since Wasmtime isn't using those things
anyways).
The sample program in cranelift/filetests/src/function_runner.rs
would abort with an mprotect failure under certain circumstances,
see https://github.com/bytecodealliance/wasmtime/pull/4453#issuecomment-1303803222
Root cause was that enabling PROT_EXEC on the main process heap
may be prohibited, depending on Linux distro and version.
This only shows up in the doc test sample program because the main
clif-util is multi-threaded and therefore allocations will happen
on glibc's per-thread heap, which is allocated via mmap, and not
the main process heap.
Work around the problem by enabling the "selinux-fix" feature of
the cranelift-jit crate dependency in the filetests. Note that
this didn't compile out of the box, so a separate fix is also
required and provided as part of this PR.
Going forward, it would be preferable to always use mmap to allocate
the backing memory for JITted code.
* Leverage Cargo's workspace inheritance feature
This commit is an attempt to reduce the complexity of the Cargo
manifests in this repository with Cargo's workspace-inheritance feature
becoming stable in Rust 1.64.0. This feature allows specifying fields in
the root workspace `Cargo.toml` which are then reused throughout the
workspace. For example this PR shares definitions such as:
* All of the Wasmtime-family of crates now use `version.workspace =
true` to have a single location which defines the version number.
* All crates use `edition.workspace = true` to have one default edition
for the entire workspace.
* Common dependencies are listed in `[workspace.dependencies]` to avoid
typing the same version number in a lot of different places (e.g. the
`wasmparser = "0.89.0"` is now in just one spot.
Currently the workspace-inheritance feature doesn't allow having two
different versions to inherit, so all of the Cranelift-family of crates
still manually specify their version. The inter-crate dependencies,
however, are shared amongst the root workspace.
This feature can be seen as a method of "preprocessing" of sorts for
Cargo manifests. This will help us develop Wasmtime but shouldn't have
any actual impact on the published artifacts -- everything's dependency
lists are still the same.
* Fix wasi-crypto tests
This commit replaces #4869 and represents the actual version bump that
should have happened had I remembered to bump the in-tree version of
Wasmtime to 1.0.0 prior to the branch-cut date. Alas!
* cranelift: Use JIT in runtests
Using `cranelift-jit` in run tests allows us to preform relocations and
libcalls. This is important since some instruction lowerings fallback
to libcall's when an extension is missing, or when it's too complicated
to implement manually.
This is also a first step to being able to test `call`'s between functions
in the runtest suite. It should also make it easier to eventually test
TLS relocations, symbol resolution and ABI's.
Another benefit of this is that we also get to test the JIT more, since
it now runs the runtests, and gets some fuzzing via `fuzzgen` (which
uses the `SingleFunctionCompiler`).
This change causes regressions in terms of runtime for the filetests.
I haven't done any serious benchmarking but what I've been seeing is
that it now takes about ~3 seconds to run the testsuite while it
previously took around 2 seconds.
* Add FMA tests for X86
* Upgrade all crates to the Rust 2021 edition
I've personally started using the new format strings for things like
`panic!("some message {foo}")` or similar and have been upgrading crates
on a case-by-case basis, but I think it probably makes more sense to go
ahead and blanket upgrade everything so 2021 features are always
available.
* Fix compile of the C API
* Fix a warning
* Fix another warning
* Bump to 0.36.0
* Add a two-week delay to Wasmtime's release process
This commit is a proposal to update Wasmtime's release process with a
two-week delay from branching a release until it's actually officially
released. We've had two issues lately that came up which led to this proposal:
* In #3915 it was realized that changes just before the 0.35.0 release
weren't enough for an embedding use case, but the PR didn't meet the
expectations for a full patch release.
* At Fastly we were about to start rolling out a new version of Wasmtime
when over the weekend the fuzz bug #3951 was found. This led to the
desire internally to have a "must have been fuzzed for this long"
period of time for Wasmtime changes which we felt were better
reflected in the release process itself rather than something about
Fastly's own integration with Wasmtime.
This commit updates the automation for releases to unconditionally
create a `release-X.Y.Z` branch on the 5th of every month. The actual
release from this branch is then performed on the 20th of every month,
roughly two weeks later. This should provide a period of time to ensure
that all changes in a release are fuzzed for at least two weeks and
avoid any further surprises. This should also help with any last-minute
changes made just before a release if they need tweaking since
backporting to a not-yet-released branch is much easier.
Overall there are some new properties about Wasmtime with this proposal
as well:
* The `main` branch will always have a section in `RELEASES.md` which is
listed as "Unreleased" for us to fill out.
* The `main` branch will always be a version ahead of the latest
release. For example it will be bump pre-emptively as part of the
release process on the 5th where if `release-2.0.0` was created then
the `main` branch will have 3.0.0 Wasmtime.
* Dates for major versions are automatically updated in the
`RELEASES.md` notes.
The associated documentation for our release process is updated and the
various scripts should all be updated now as well with this commit.
* Add notes on a security patch
* Clarify security fixes shouldn't be previewed early on CI
In #3721, we have been discussing what to do about the ARM32 backend in
Cranelift. Currently, this backend supports only 32-bit types, which is
insufficient for full Wasm-MVP; it's missing other critical bits, like
floating-point support; and it has only ever been exercised, AFAIK, via
the filetests for the individual CLIF instructions that are implemented.
We were very very thankful for the original contribution of this
backend, even in its partial state, and we had hoped at the time that we
could eventually mature it in-tree until it supported e.g. Wasm and
other use-cases. But that hasn't yet happened -- to the blame of no-one,
to be clear, we just haven't had a contributor with sufficient time.
Unfortunately, the existence of the backend and lack of active
maintainer now potentially pose a bit of a burden as we hope to make
continuing changes to the backend framework. For example, the ISLE
migration, and the use of regalloc2 that it will allow, would need all
of the existing lowering patterns in the hand-written ARM32 backend to
be rewritten as ISLE rules.
Given that we don't currently have the resources to do this, we think
it's probably best if we, sadly, for now remove this partial backend.
This is not in any way a statement of what we might accept in the
future, though. If, in the future, an ARM32 backend updated to our
latest codebase with an active maintainer were to appear, we'd be happy
to merge it (and likewise for any other architecture!). But for now,
this is probably the best path. Thanks again to the original contributor
@jmkrauz and we hope that this work can eventually be brought back and
reused if someone has the time to do so!
Peepmatic was an early attempt at a DSL for peephole optimizations, with the
idea that maybe sometime in the future we could user it for instruction
selection as well. It didn't really pan out, however:
* Peepmatic wasn't quite flexible enough, and adding new operators or snippets
of code implemented externally in Rust was a bit of a pain.
* The performance was never competitive with the hand-written peephole
optimizers. It was *very* size efficient, but that came at the cost of
run-time efficiency. Everything was table-based and interpreted, rather than
generating any Rust code.
Ultimately, because of these reasons, we never turned Peepmatic on by default.
These days, we just landed the ISLE domain-specific language, and it is better
suited than Peepmatic for all the things that Peepmatic was originally designed
to do. It is more flexible and easy to integrate with external Rust code. It is
has better time efficiency, meeting or even beating hand-written code. I think a
small part of the reason why ISLE excels in these things is because its design
was informed by Peepmatic's failures. I still plan on continuing Peepmatic's
mission to make Cranelift's peephole optimizer passes generated from DSL rewrite
rules, but using ISLE instead of Peepmatic.
Thank you Peepmatic, rest in peace!
* Upgrade to the latest versions of gimli, addr2line, object
And adapt to API changes. New gimli supports wasm dwarf, resulting in
some simplifications in the debug crate.
* upgrade gimli usage in linux-specific profiling too
* Add "continue" statement after interpreting a wasm local dwarf opcode
This removes an existing dependency on the byteorder crate in favor of
using std equivalents directly.
While not an issue for wasmtime per se, cranelift is now part of the
critical path of building and testing Rust, and minimizing dependencies,
even small ones, can help reduce the time and bandwidth required.
This PR switches the default backend on x86, for both the
`cranelift-codegen` crate and for Wasmtime, to the new
(`MachInst`-style, `VCode`-based) backend that has been under
development and testing for some time now.
The old backend is still available by default in builds with the
`old-x86-backend` feature, or by requesting `BackendVariant::Legacy`
from the appropriate APIs.
As part of that switch, it adds some more runtime-configurable plumbing
to the testing infrastructure so that tests can be run using the
appropriate backend. `clif-util test` is now capable of parsing a
backend selector option from filetests and instantiating the correct
backend.
CI has been updated so that the old x86 backend continues to run its
tests, just as we used to run the new x64 backend separately.
At some point, we will remove the old x86 backend entirely, once we are
satisfied that the new backend has not caused any unforeseen issues and
we do not need to revert.
This bumps target-lexicon and adds support for the AppleAarch64 calling
convention. Specifically for WebAssembly support, we only have to worry
about the new stack slots convention. Stack slots don't need to be at
least 8-bytes, they can be as small as the data type's size. For
instance, if we need stack slots for (i32, i32), they can be located at
offsets (+0, +4). Note that they still need to be properly aligned on
the data type they're containing, though, so if we need stack slots for
(i32, i64), we can't start the i64 slot at the +4 offset (it must start
at the +8 offset).
Added one test that was failing on the Mac M1, as well as other tests
stressing different yet similar situations.
I don't think this has happened in awhile but I've run a `cargo update`
as well as trimming some of the duplicate/older dependencies in
`Cargo.lock` by updating some of our immediate dependencies as well.
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.
