Multi-variant layouts for generators
This allows generators to overlap fields using variants, but doesn't do any such overlapping yet. It creates one variant for every state of the generator (unresumed, returned, panicked, plus one for every yield), and puts every stored local in each of the yield-point variants.
Required for optimizing generator layouts (#52924).
There was quite a lot of refactoring needed for this change. I've done my best in later commits to eliminate assumptions in the code that only certain kinds of types are multi-variant, and to centralize knowledge of the inner mechanics of generators in as few places as possible.
This change also emits debuginfo about the fields contained in each variant, as well as preserving debuginfo about stored locals while running in the generator.
Also, fixes#59972.
Future work:
- Use this change for an optimization pass that actually overlaps locals within the generator struct (#52924)
- In the type layout fields, don't include locals that are uninitialized for a particular variant, so miri and UB sanitizers can check our memory (see https://github.com/rust-lang/rust/issues/59972#issuecomment-483058172)
- Preserve debuginfo scopes across generator yield points
[NLL] Type check operations with pointer types
It seems these were forgotten about. Moving to `Rvalue::AddressOf` simplifies the coercions from references, but I want this to be fixed as soon as possible.
r? @pnkfelix
Make `intern_lazy_const` actually intern its argument.
Currently it just unconditionally allocates it in the arena.
For a "Clean Check" build of the the `packed-simd` benchmark, this
change reduces both the `max-rss` and `faults` counts by 59%; it
slightly (~3%) increases the instruction counts but the `wall-time` is
unchanged.
For the same builds of a few other benchmarks, `max-rss` and `faults`
drop by 1--5%, but instruction counts and `wall-time` changes are in the
noise.
Fixes#57432, fixes#57829.
Currently it just unconditionally allocates it in the arena.
For a "Clean Check" build of the the `packed-simd` benchmark, this
change reduces both the `max-rss` and `faults` counts by 59%; it
slightly (~3%) increases the instruction counts but the `wall-time` is
unchanged.
For the same builds of a few other benchmarks, `max-rss` and `faults`
drop by 1--5%, but instruction counts and `wall-time` changes are in the
noise.
Fixes#57432, fixes#57829.
This commit refactors the `UserTypeAnnotation` type to be referred to by
an index within `UserTypeProjection`. `UserTypeAnnotation` is instead
kept in an `IndexVec` within the `Mir` struct.
Further, instead of `UserTypeAnnotation` containing canonicalized types,
it now contains normal types and the entire `UserTypeAnnotation` is
canonicalized. To support this, the type was moved from the `rustc::mir`
module to `rustc::ty` module.
csmoe
Santiago Pastorino
Eduard-Mihai Burtescu
Saleem Jaffer
Ralf Jung
Mark Rousskov
Wesley Wiser
Matthew Jasper
John Kåre Alsaker
Mazdak Farrokhzad
bors
varkor
Tyler Mandry
Saleem Jaffer
kenta7777
Taiki Endo
Oliver Scherer
Nicholas Nethercote
David Wood
Alexander Regueiro
Felix S. Klock II
Keith Yeung
Mikhail Modin