Add some pre-codegen MIR tests for debug mode
No functional changes; just some tests.
I made these for rust-lang/rust#144483, but that's going in a different direction, so I wanted to propose we just add them to help see the impact of other related changes in the future.
r? mir
`AlignmentEnum` should just be `repr(usize)` now
These used to use specific sizes because they were compiled on all widths. But now that the types themselves are `#[cfg]`'d, we can save some conversions by having it always be `repr(usize)`.
Rollup of 3 pull requests
Successful merges:
- rust-lang/rust#144657 (fix: Only "close the window" when its the last annotated file)
- rust-lang/rust#144665 (Re-block SRoA on SIMD types)
- rust-lang/rust#144713 (`rustc_middle::ty` cleanups)
r? `@ghost`
`@rustbot` modify labels: rollup
coverage: Re-land "Enlarge empty spans during MIR instrumentation"
This allows us to assume that coverage spans will only be discarded during codegen in very unusual situations.
---
This seemingly-simple change has a rather messy history:
- rust-lang/rust#140847
- rust-lang/rust#141650
- rust-lang/rust#144298
- rust-lang/rust#144480
Since then, a number of related changes have landed that should make it reasonable to try again:
- rust-lang/rust#144530
- rust-lang/rust#144560
- rust-lang/rust#144616
In particular, we have multiple fixes/mitigations, and a confirmed regression test for the original bug that is not triggered by re-landing the changes in this PR.
Fix Box allocator drop elaboration
New version of rust-lang/rust#131146.
Clearing Box's drop flag after running its destructor can cause it to skip dropping its allocator, so just don't. Its cleared by the drop ladder code afterwards already.
Unlike the last PR this also handles other types with destructors properly, in the event that we can have open drops on them in the future (by partial initialization or DerefMove or something).
Finally, I also added tests for the interaction with async drop here but I discovered rust-lang/rust#143658, so one of the tests has a `knownbug` annotation. Not sure if it should be in this PR at all though.
Fixesrust-lang/rust#131082
r? wesleywiser - prev. reviewer
MIR-build: No longer emit assumes in enum-as casting
This just uses the `valid_range` from the backend, so it's duplicating the range metadata that now we include on parameters and loads, and thus no longer seems to be useful -- notably there's no codegen test failures from removing it.
(Because it's using data from the same source as the backend annotations, it doesn't do anything to mitigate things like rust-lang/rust#144388 where the range in the layout is more permissive than the actual possible discriminants. A variant of this that actually checked the discriminants more specifically might be useful, so could potentially be added in future, but I don't think the *current* checks are actually providing value.)
r? mir
Randomly turns out that this
Fixes https://github.com/rust-lang/rust/issues/121097
Store the type of each GVN value
MIR is fully typed, so type information is an integral part of what defines a value. GVN currently tries to circumvent storing types, which creates all sorts of complexities.
This PR stores the type along with the enum `Value` when defining a value index. This allows to simplify a lot of code.
Fixesrust-lang/rust#128094Fixesrust-lang/rust#135128
r? ``````@ghost`````` for perf
Only inherit local hash for paths
`DefPathHash`, as the counterpart of `DefId` that is stable across compiler invocations, is comprised of 2 parts. The first one is the `StableCrateId`, stable form of `CrateNum`. The second is 64 complementary bits to identify the crate-local definition.
The current implementation always hashes the full 128 bits when (1) trying to create a new child `DefPathHash` or (2) hashing a `CrateNum` or a `LocalDefId`. But we only need half that information: `LocalDefId` means that the `StableCrateId` is always the current crate's ; `CrateNum` means that we do not care about the local part.
As stable hashing is very hot in the query system, in particular hashing definitions, this is a big deal.
We still want the local part to change when the `StableCrateId` changes, to make incr-compilation errors less painful, ie. increase the likelihood that if will magically disappear by changing some code.
This PR sprinkles some `#[inline]` attributes on small functions that appeared in profiles.
Apply effects to `otherwise` edge in dataflow analysis
This allows `ElaborateDrops` to remove drops when a `match` wildcard arm covers multiple no-Drop enum variants. It modifies dataflow analysis to update the `MaybeUninitializedPlaces` and `MaybeInitializedPlaces` data for a block reached through an `otherwise` edge.
Fixesrust-lang/rust#142705.
Dont resolve instance of root in `mir_callgraph_cyclic`
`Instance::try_resolve` on a default trait body method will always fail, since it's still possible to further substitute. This leads to a cycle, since in `tests/mir-opt/inline_default_trait_body.rs`, both `Trait::a` and `Trait::b` need to consider the other to be cyclical, but since we couldn't resolve a body, we'd just consider *nothing* to be cyclical.
The root instance we care about when computing `mir_callgraph_cyclic` is trivial to compute (it's just `InstanceKind::Item`), so just replace it with a call to `Instance::new_raw`.
r? `@cjgillot` `@oli-obk`
Fixesrust-lang/rust#143534
Reason about borrowed classes in CopyProp.
Fixes https://github.com/rust-lang/rust/issues/141122
The current implementation of `CopyProp` avoids unifying two borrowed locals, as this would change the result of address comparison.
However, the implementation was inconsistent with the general algorithm, which identifies equivalence classes of locals and then replaces all locals by a single representative of their equivalence class.
This PR fixes it by forbidding the unification of two *classes* if any of those contain a borrowed local.
