* func_wrap_async typechecks
* func call async
* instantiate_async
* fixes
* async engine creation for tests
* start adding a component model test for async
* fix wrong check for async support, factor out Instance::new_started to an unchecked impl
* tests: wibbles
* component::Linker::func_wrap: replace IntoComponentFunc with directly accepting a closure
We find that this makes the Linker::func_wrap type signature much easier
to read. The IntoComponentFunc abstraction was adding a lot of weight to
"splat" a set of arguments from a tuple of types into individual
arguments to the closure. Additionally, making the StoreContextMut
argument optional, or the Result<return> optional, wasn't very
worthwhile.
* Fixes for the new style of closure required by component::Linker::func_wrap
* future of result of return
* add Linker::instantiate_async and {Typed}Func::post_return_async
* fix fuzzing generator
* note optimisation opportunity
* simplify test
* Add egraphs option to Wasmtime config, and add it to fuzzing config generation.
This PR adds a wrapper method for Cranelift's `use_egraphs` setting to
Wasmtime's `Config`, named `cranelift_use_egraphs` analogously to its
existing `cranelift_opt_level`.
Eventually this should become a no-op as egraph-based optimization
becomes the default, but until then it makes sense to expose this as
another kind of optimization option.
This PR then adds the option to the `Arbitrary`-based config generation
for fuzzing, so compilation with egraphs will be fuzzed (on its own and
against other configurations and oracles).
* Don't use `NamedTempFile` on Windows
It looks like this prevents mmap-ing since the named temporary file
holds a `File` open which conflicts with the rights we're trying to open
the file for mmap-ing. Instead use a temporary directory to try to fix
this issue.
Co-authored-by: Alex Crichton <alex@alexcrichton.com>
* component::Linker::func_wrap: replace IntoComponentFunc with directly accepting a closure
We find that this makes the Linker::func_wrap type signature much easier
to read. The IntoComponentFunc abstraction was adding a lot of weight to
"splat" a set of arguments from a tuple of types into individual
arguments to the closure. Additionally, making the StoreContextMut
argument optional, or the Result<return> optional, wasn't very
worthwhile.
* Fixes for the new style of closure required by component::Linker::func_wrap
* fix fuzzing generator
Remove the boolean types from cranelift, and the associated instructions breduce, bextend, bconst, and bint. Standardize on using 1/0 for the return value from instructions that produce scalar boolean results, and -1/0 for boolean vector elements.
Fixes#3205
Co-authored-by: Afonso Bordado <afonso360@users.noreply.github.com>
Co-authored-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Co-authored-by: Chris Fallin <chris@cfallin.org>
This is a simple error in the const-prop rules: uextend was not
masking iconst's u64 immediate when extending from i32 to
i64. Arguably an iconst.i32 should not have nonzero bits in the upper
32 of its immediate, but that's a separate design question. For now,
if our invariant is that the upper bits are ignored, then it is
required to mask the bits when const-evaling a `uextend`.
Fixes#5047.
* Plumb type exports in components around more
This commit adds some more plumbing for type exports to ensure that they
show up in the final compiled representation of a component. For now
they continued to be ignored for all purposes in the embedding API
itself but I found this useful to explore in `wit-bindgen` based tooling
which is leveraging the component parsing in Wasmtime.
* Add a field to `ModuleTranslation` to store the original wasm
This commit adds a field to be able to refer back to the original wasm
binary for a `ModuleTranslation`. This field is used in the upcoming
support for host generation in `wit-component` to "decompile" a
component into core wasm modules to get instantiated. This is used to
extract a core wasm module from the original component.
* FIx a build warning
* Add a benchmark for traps with many Wasm<-->host calls on the stack
* Add a test for expected Wasm stack traces with Wasm<--host calls on the stack when we trap
* Don't re-capture backtraces when propagating traps through host frames
This fixes some accidentally quadratic code where we would re-capture a Wasm
stack trace (takes `O(n)` time) every time we propagated a trap through a host
frame back to Wasm (can happen `O(n)` times). And `O(n) * O(n) = O(n^2)`, of
course. Whoops. After this commit, it trapping with a call stack that is `n`
frames deep of Wasm-to-host-to-Wasm calls just captures a single backtrace and
is therefore just a proper `O(n)` time operation, as it is intended to be.
Now we explicitly track whether we need to capture a Wasm backtrace or not when
raising a trap. This unfortunately isn't as straightforward as one might hope,
however, because of the split between `wasmtime::Trap` and
`wasmtime_runtime::Trap`. We need to decide whether or not to capture a Wasm
backtrace inside `wasmtime_runtime` but in order to determine whether to do that
or not we need to reflect on the `anyhow::Error` and see if it is a
`wasmtime::Trap` that already has a backtrace or not. This can't be done the
straightforward way because it would introduce a cyclic dependency between the
`wasmtime` and `wasmtime-runtime` crates. We can't merge those two `Trap`
types-- at least not without effectively merging the whole `wasmtime` and
`wasmtime-runtime` crates together, which would be a good idea in a perfect
world but would be a *ton* of ocean boiling from where we currently are --
because `wasmtime::Trap` does symbolication of stack traces which relies on
module registration information data that resides inside the `wasmtime` crate
and therefore can't be moved into `wasmtime-runtime`. We resolve this problem by
adding a boolean to `wasmtime_runtime::raise_user_trap` that controls whether we
should capture a Wasm backtrace or not, and then determine whether we need a
backtrace or not at each of that function's call sites, which are in `wasmtime`
and therefore can do the reflection to determine whether the user trap already
has a backtrace or not. Phew!
Fixes#5037
* debug assert that we don't record unnecessary backtraces for traps
* Add assertions around `needs_backtrace`
Unfortunately we can't do
debug_assert_eq!(needs_backtrace, trap.inner.backtrace.get().is_some());
because `needs_backtrace` doesn't consider whether Wasm backtraces have been
disabled via config.
* Consolidate `needs_backtrace` calculation followed by calling `raise_user_trap` into one place
* allow a ComponentTypeRef::Type to point to a component TypeDef
* component matching: don't assert exported Interface type definitions are "defined"
types may be exported by their name for consumption by some component
runtimes, but in wasmtime this doesn't matter (we lift and lower to
types, not define them) so we should ignore these.
* component-model instance tests: show that an import can export a type definition
this is meaningless, but it should be accepted. (previously rejected)
* cranelift: Add FlushInstructionCache for AArch64 on Windows
This was previously done on #3426 for linux.
* wasmtime: Add FlushInstructionCache for AArch64 on Windows
This was previously done on #3426 for linux.
* cranelift: Add MemoryUse flag to JIT Memory Manager
This allows us to keep the icache flushing code self-contained and not leak implementation details.
This also changes the windows icache flushing code to only flush pages that were previously unflushed.
* Add jit-icache-coherence crate
* cranelift: Use `jit-icache-coherence`
* wasmtime: Use `jit-icache-coherence`
* jit-icache-coherence: Make rustix feature additive
Mutually exclusive features cause issues.
* wasmtime: Remove rustix from wasmtime-jit
We now use it via jit-icache-coherence
* Rename wasmtime-jit-icache-coherency crate
* Use cfg-if in wasmtime-jit-icache-coherency crate
* Use inline instead of inline(always)
* Add unsafe marker to clear_cache
* Conditionally compile all rustix operations
membarrier does not exist on MacOS
* Publish `wasmtime-jit-icache-coherence`
* Remove explicit windows check
This is implied by the target_os = "windows" above
* cranelift: Remove len != 0 check
This is redundant as it is done in non_protected_allocations_iter
* Comment cleanups
Thanks @akirilov-arm!
* Make clear_cache safe
* Rename pipeline_flush to pipeline_flush_mt
* Revert "Make clear_cache safe"
This reverts commit 21165d81c9.
* More docs!
* Fix pipeline_flush reference on clear_cache
* Update more docs!
* Move pipeline flush after `mprotect` calls
Technically the `clear_cache` operation is a lie in AArch64, so move the pipeline flush after the `mprotect` calls so that it benefits from the implicit cache cleaning done by it.
* wasmtime: Remove rustix backend from icache crate
* wasmtime: Use libc for macos
* wasmtime: Flush icache on all arch's for windows
* wasmtime: Add flags to membarrier call
* egraph-based midend: draw the rest of the owl.
* Rename `egg` submodule of cranelift-codegen to `egraph`.
* Apply some feedback from @jsharp during code walkthrough.
* Remove recursion from find_best_node by doing a single pass.
Rather than recursively computing the lowest-cost node for a given
eclass and memoizing the answer at each eclass node, we can do a single
forward pass; because every eclass node refers only to earlier nodes,
this is sufficient. The behavior may slightly differ from the earlier
behavior because we cannot short-circuit costs to zero once a node is
elaborated; but in practice this should not matter.
* Make elaboration non-recursive.
Use an explicit stack instead (with `ElabStackEntry` entries,
alongside a result stack).
* Make elaboration traversal of the domtree non-recursive/stack-safe.
* Work analysis logic in Cranelift-side egraph glue into a general analysis framework in cranelift-egraph.
* Apply static recursion limit to rule application.
* Fix aarch64 wrt dynamic-vector support -- broken rebase.
* Topo-sort cranelift-egraph before cranelift-codegen in publish script, like the comment instructs me to!
* Fix multi-result call testcase.
* Include `cranelift-egraph` in `PUBLISHED_CRATES`.
* Fix atomic_rmw: not really a load.
* Remove now-unnecessary PartialOrd/Ord derivations.
* Address some code-review comments.
* Review feedback.
* Review feedback.
* No overlap in mid-end rules, because we are defining a multi-constructor.
* rustfmt
* Review feedback.
* Review feedback.
* Review feedback.
* Review feedback.
* Remove redundant `mut`.
* Add comment noting what rules can do.
* Review feedback.
* Clarify comment wording.
* Update `has_memory_fence_semantics`.
* Apply @jameysharp's improved loop-level computation.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fix suggestion commit.
* Fix off-by-one in new loop-nest analysis.
* Review feedback.
* Review feedback.
* Review feedback.
* Use `Default`, not `std::default::Default`, as per @fitzgen
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
* Apply @fitzgen's comment elaboration to a doc-comment.
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
* Add stat for hitting the rewrite-depth limit.
* Some code motion in split prelude to make the diff a little clearer wrt `main`.
* Take @jameysharp's suggested `try_into()` usage for blockparam indices.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Take @jameysharp's suggestion to avoid double-match on load op.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fix suggestion (add import).
* Review feedback.
* Fix stack_load handling.
* Remove redundant can_store case.
* Take @jameysharp's suggested improvement to FuncEGraph::build() logic
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Tweaks to FuncEGraph::build() on top of suggestion.
* Take @jameysharp's suggested clarified condition
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Clean up after suggestion (unused variable).
* Fix loop analysis.
* loop level asserts
* Revert constant-space loop analysis -- edge cases were incorrect, so let's go with the simple thing for now.
* Take @jameysharp's suggestion re: result_tys
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fix up after suggestion
* Take @jameysharp's suggestion to use fold rather than reduce
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fixup after suggestion
* Take @jameysharp's suggestion to remove elaborate_eclass_use's return value.
* Clarifying comment in terminator insts.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
* Cranelift: Make `Opcode` represented as a `u8` instead of `u16`
* Cranelift: Remove unused conversion impls for `Opcode`
These are vestigial, left over from Peepmatic.
In #5023 we are seeing a failing CI job (see [1]); after four attempted
restarts, it 404's each time when trying to download OpenVino from the
Intel apt mirrors.
This PR temporarily removes the wasi-nn CI job from our CI configuration
so that we have green CI and can merge other work.
[1] https://github.com/bytecodealliance/wasmtime/actions/runs/3200861896/jobs/5228903240
* Fix StructReturn handling: properly mark the clobber, and offset actual rets.
The legalization of `StructReturn` was causing issues in the new
call-handling code: the `StructReturn` ret was included in the `SigData` as
if it were an actual CLIF-level return value, but it is not.
Prior to using regalloc constraints for return values, we
unconditionally included rax (or the architecture's usual return
register) as a def, so it would be properly handled as "clobbered" by
the regalloc. With the new scheme, we include defs on the call only for
CLIF-level outputs. Callees with `StructReturn` args were thus not known
to clobber the return-value register, and values might be corrupted.
This PR updates the code to include a `StructReturn` ret as a clobber
rather than a returned value in the relevant spots. I observed it
causing saves/restores of rax in some CLIF that @bjorn3 provided me, but
I was having difficulty minimizing this into a test-case that I would be
comfortable including as a precise-output case (including the whole
thing verbatim would lock down a bunch of other irrelevant details and
cause test-update noise later). If we can find a more minimized example
I'm happy to include it as a filetest.
Fixes#5018.
* Replace resize+copy_from_slice with extend_from_slice
Vec::resize initializes the new space, which is wasted effort if we're
just going to call `copy_from_slice` on it immediately afterward. Using
`extend_from_slice` is simpler, and very slightly faster.
If the new size were bigger than the buffer we're copying from, then it
would make sense to initialize the excess. But it isn't: it's always
exactly the same size.
* Move helpers from Context to CompiledCode
These methods only use information from Context::compiled_code, so they
should live on CompiledCode instead.
* Remove an unnecessary #[cfg_attr]
There are other uses of `#[allow(clippy::too_many_arguments)]` in this
file, so apparently it doesn't need to be guarded by the "cargo-clippy"
feature.
* Fix a few comments
Two of these were wrong/misleading:
- `FunctionBuilder::new` does not clear the provided func_ctx. It does
debug-assert that the context is already clear, but I don't think
that's worth a comment.
- `switch_to_block` does not "create values for the arguments." That's
done by the combination of `append_block_params_for_function_params`
and `declare_wasm_parameters`.
* wasmtime-cranelift: Misc cleanups
The main change is to use the `CompiledCode` reference we already had
instead of getting it out of `Context` repeatedly. This removes a bunch
of `unwrap()` calls.
* wasmtime-cranelift: Factor out uncached compile
When implementing custom WasiDir instances, there is a lot of
boilerplate. These default methods should reduce code for implementors
who want to provide only a subset of functionality.
Signed-off-by: Nathaniel McCallum <nathaniel@profian.com>
Signed-off-by: Nathaniel McCallum <nathaniel@profian.com>
* Tidy up the WASI `ErrorKind` enum.
`ErrorKind` is an internal enum used in wasi-libc to represent WASI
errors that aren't precisely represened by `std::io::ErrorKind` errors.
Add a descriptive comment, and remove some codes that are no longer
needed:
- Remove `NotCapable`, which is no longer used.
- Remove `WouldBlk`, `Exist`, `Noent`, and `Inval`, which have
one-to-one correspondences with codes in `std::io::ErrorKind`.
This will simplify the error handling in #4947 and #4967, as it means
the code will no longer have to check for two different forms of these
errors.
* Map `std::io::ErrorKind::InvalidInput` to `Ok(types::Errno::Inval)`.
Besides the standard traits (Copy, Clone, PartialEq and Eq), we also mark
the trait as non-exhaustive so that we can add errors in the future
without breaking API.
Signed-off-by: Nathaniel McCallum <nathaniel@profian.com>
Signed-off-by: Nathaniel McCallum <nathaniel@profian.com>
A minor update of a few other crates drops `semver` and `rustc_version`
from `Cargo.lock`. I've audited the deltas in versions for the other
crates here as well and they all look good.
* Elide redundant sentinel values
The `undef_variables` lists were a binding from Variable to Value, but
the Values were always equal to a suffix of the block's parameters. So
instead of storing another copy, we can just get them back from the
block parameters.
According to DHAT, this decreases total memory allocated and number of
bytes written, and increases number of bytes read and instructions
retired, but all by small fractions of a percent. According to
hyperfine, main is "1.00 ± 0.01 times faster".
* Use entity_impl for cranelift_frontend::Variable
Instead of hand-coding essentially the same thing.
* Keep undefined variables in a ListPool
According to DHAT, this improves every measure of performance
(instructions retired, total memory allocated, max heap size, bytes
read, and bytes written), although by fractions of a percent. According
to hyperfine the difference is nearly zero, but on Spidermonkey this
branch is "1.01 ± 0.00 times faster" than main.
* Elide redundant block IDs
In a list of predecessors, we previously kept both the jump instruction
that points to the current block, and the block where that instruction
resides. But we can look up the block from the instruction as long as we
have access to the current Layout, which we do everywhere that it was
necessary. So don't store the block, just store the instruction.
* Keep predecessor definitions in a ListPool
* Make append_jump_argument independent of self
This makes it easier to reason about borrow-checking issues.
* Reuse `results` instead of re-doing variable lookup
This eliminates three array lookups per predecessor by hanging on to the
results of earlier steps a little longer. This only works now because I
previously removed the need to borrow all of `self`, which otherwise
prevented keeping a borrow of self.results alive.
I had experimented with using `Vec::split_off` to copy the relevant
chunk of results to a temporary heap allocation, but the extra
allocation and copy was measurably slower. So it's important that this
is just a borrow.
* Cache single-predecessor block ID when sealing
Of the code in cranelift_frontend, `use_var` is the second-hottest path,
sitting close behind the `build` function that's used when inserting
every new instruction. This makes sense given that the operands of a new
instruction usually need to be looked up immediately before building the
instruction.
So making the single-predecessor loops in `find_var` and `use_var_local`
do fewer memory accesses and execute fewer instructions turns out to
have a measurable effect. It's still only a small fraction of a percent
overall since cranelift-frontend is only a few percent of total runtime.
This patch keeps a block ID in the SSABlockData, which is None unless
both the block is sealed and it has exactly one predecessor. Doing so
avoids two array lookups on each iteration of the two loops.
According to DHAT, compared with main, at this point this PR uses 0.3%
less memory at max heap, reads 0.6% fewer bytes, and writes 0.2% fewer
bytes.
According to Hyperfine, this PR is "1.01 ± 0.01 times faster" than main
when compiling Spidermonkey. On the other hand, Sightglass says main is
1.01x faster than this PR on the same benchmark by CPU cycles. In short,
actual effects are too small to measure reliably.
Minor thing I noticed from #4990 but I stylistically prefer to keep the
`mod foo;` definitions canonicalized to one location to emphasize how
multiple targets can use the same definition.
* Make wasmtime build for windows-aarch64
* Add check for win arm64 build.
* Fix checks for winarm64 key in workflows.
* Add target in windows arm64 build.
* Add tracking issue for Windows ARM64 trap handling
* cranelift-wasm: Assume block is reachable
In handling the WebAssembly "end" operator, cranelift-wasm had logic to
skip generating a jump instruction if the block was both unreachable and
"pristine", meaning no instructions had been added.
However, `translate_operator` checks first that `state.reachable` is
true, so this logic only runs when cranelift-wasm believes that the
current block _is_ reachable. Therefore the condition should always be
true, whether the block is pristine or not.
I've left a debug_assert in case `state.reachable` ever doesn't agree
with `builder.is_unreachable()`, but the assert doesn't fail in any of
the tests. We'll see if fuzzing finds something.
Anyway, outside of cranelift-frontend, this eliminates the only use of
`is_pristine()`, and there were no uses of `is_filled()`. So I've made
both of those private. They're now only used in a nearby debug assert.
* cranelift-frontend: Clarify pristine/filled states
There was a comment here saying "A filled block cannot be pristine."
Given that the intent was for those two states to be mutually exclusive,
I've replaced the two booleans with a three-state enum.
I also replaced all reads of these two flags with method calls. In all
but one case these are only checked in debug assertions, so I don't even
care whether they get inlined. They're easier to read, and this will
make it easier to replace their implementations, which I hope to do
soon.
Finally, I replaced all assignments to either flag with an appropriate
assignment of the corresponding enum state. Keep in mind this
correspondence between the new enum and the old flags:
- Empty: pristine true, filled false
- Partial: pristine false, filled false
- Filled: pristine false, filled true
Every existing update to these flags could only move to a later state.
(For example, Partial couldn't go back to Empty.) In the old flags that
meant that pristine could only go from true to false, and filled could
only go from false to true.
`fill_current_block` was a weird case because at first glance it looks
like it could allow both pristine and filled to be true at the same
time. However, it's only called from `FuncInstBuilder::build`, which
calls `ensure_inserted_block` before doing anything else, and _that_
cleared the pristine flag.
Similarly, `handle_ssa_side_effects` looks like it could allow both
pristine and filled to be true for anything in `split_blocks_created`.
However, those blocks are created by SSABuilder, so their BlockData is
not initialized by `create_block`, and instead uses BlockData::default.
The `Default` implementation here previously set both flags false, while
`create_block` would instead set pristine to true. So these split blocks
were correctly set to the Filled state, and after this patch they are
still set correctly.
* cranelift-frontend: Separate SSA and user block params
Previously there was a `user_param_count` field in BlockData, used
purely to debug-assert that no user parameters are added to a block
after `use_var` adds SSA parameters.
Instead, this patch enforces a strict phase separation between the
period after a block is created when user parameters can be added to it,
and the period when `use_var` may be called and instructions may be
added.
I'm assuming that calls to `use_var` are _always_ followed by inserting
one or more instructions into the block. (If you don't want to insert an
instruction, why do you need to know where instructions in this block
would get variable definitions from?) This patch has no visible effect
for callers which follow that rule.
However, it was previously legal to call `use_var`, then append a block
parameter before adding instructions, so long as `use_var` didn't
actually need to add a block parameter. That could only happen if the
current block is sealed and has exactly one predecessor. So anyone who
was counting on this behavior was playing a dangerous game anyway.
* cranelift-frontend: Defer initializing block data
Every reference to the func_ctx.status SecondaryMap will automatically
create the appropriate entries on-demand, with the sole exception of
`finalize`. In that function, debug assertions use SecondaryMap::keys to
find out which blocks need to be checked.
However, those assertions always succeed for blocks which never had any
instructions added. So it's okay to skip them for blocks which aren't
touched after `create_block`.
Resolve overlap in the RiscV64 backend by adding priorities to rules. Additionally, one test updated as a result of this work, as a peephole optimization for addition with immediates fires now.
* Cleanups to cranelift-frontend SSA construction
* Encode sealed/undef_variables relationship in type
A block can't have any undef_variables if it is sealed. It's useful to
make that fact explicit in the types so that any time either value is
used, it's clear that we should think about the other one too.
In addition, encoding this fact in an enum type lets Rust apply an
optimization that reduces the size of SSABlockData by 8 bytes, making it
fit in a 64-byte cache line. I haven't taken the extra step of making
SSABlockData be 64-byte aligned because 1) it doesn't seem to have a
performance impact and b) doing so makes other structures quite a bit
bigger.
* Simplify finish_predecessors_lookup
Using Vec::drain is more concise than a combination of
iter().rev().take() followed by Vec::truncate. And in this case it
doesn't matter what order we examine the results in, because we just
want to know if they're all equal, so we might as well iterate forward
instead of in reverse.
There's no need for the ZeroOneOrMore enum. Instead, there are only two
cases: either we have a single value to use for the variable (possibly
synthesized as a constant zero), or we need to add a block parameter in
every predecessor.
Pre-filtering the results iterator to eliminate the sentinel makes it
easy to identify how many distinct definitions this variable has.
iter.next() indicates if there are any definitions at all, and then
iter.all() is a clear way to express that we want to know if the
remaining definitions are the same as the first one.
* Simplify append_jump_argument
* Avoid assigning default() into SecondaryMap
This eliminates some redundant reads and writes.
* cranelift-frontend: Construct with default()
This eliminates a bunch of boilerplate in favor of a built in `derive`
macro.
Also I'm deleting an import that had the comment "FIXME: Remove in
edition2021", which we've been using everywhere since April.
* Fix tests
In the common case where there is a chain of sealed blocks that each
have exactly one predecessor, we can keep track of any sub-sequence of
those blocks in O(1) space. So there's no need to use the state machine
stack to propagate variable definitions back along the chain.
Instead, we can do one loop to find which block to stop at, then either
get the variable definition from that block or introduce a block
parameter there, and finally do one more loop to update variable
definitions in all the intervening blocks.
The existing implementation already had to do a graph traversal to
propagate variable definitions correctly, so this doesn't visit any more
blocks than before. However, this change also makes it possible to
integrate cycle detection with the graph traversal. That eliminates the
need for the in_predecessor_cycle flags, and any possibility of spiky
performance profiles in maintaining those flags.
As far as performance goes, this is all pretty much a wash: Changes to
CPU time and CPU cycles are within noise, according to hyperfine and
Sightglass/perf. But it's a substantially simpler implementation, with
fewer invisible interactions between functions.
Pat Hickey
Chris Fallin
Trevor Elliott
Afonso Bordado
Alex Crichton
Nick Fitzgerald
Andrew Brown
Benjamin Bouvier
Adam C. Foltzer
Jun Ryung Ju
Jimmy Bourassa
Jamey Sharp
Nathaniel McCallum
wasmtime-publish
Dan Gohman
Rainy Sinclair
yuyang
Johnnie Birch
bjorn3
Yuyi Wang