Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/next_solver/infer/canonical/canonicalizer.rs')
| -rw-r--r-- | crates/hir-ty/src/next_solver/infer/canonical/canonicalizer.rs | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/crates/hir-ty/src/next_solver/infer/canonical/canonicalizer.rs b/crates/hir-ty/src/next_solver/infer/canonical/canonicalizer.rs index 5d11525cd1..beaac11a2d 100644 --- a/crates/hir-ty/src/next_solver/infer/canonical/canonicalizer.rs +++ b/crates/hir-ty/src/next_solver/infer/canonical/canonicalizer.rs @@ -10,9 +10,8 @@ use rustc_index::Idx; use rustc_type_ir::InferTy::{self, FloatVar, IntVar, TyVar}; use rustc_type_ir::inherent::{Const as _, IntoKind as _, Region as _, SliceLike, Ty as _}; use rustc_type_ir::{ - BoundVar, CanonicalQueryInput, CanonicalTyVarKind, DebruijnIndex, Flags, InferConst, - RegionKind, TypeFlags, TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitableExt, - UniverseIndex, + BoundVar, CanonicalQueryInput, DebruijnIndex, Flags, InferConst, RegionKind, TyVid, TypeFlags, + TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitableExt, UniverseIndex, }; use smallvec::SmallVec; use tracing::debug; @@ -316,6 +315,13 @@ struct Canonicalizer<'cx, 'db> { // Note that indices is only used once `var_values` is big enough to be // heap-allocated. indices: FxHashMap<GenericArg<'db>, BoundVar>, + /// Maps each `sub_unification_table_root_var` to the index of the first + /// variable which used it. + /// + /// This means in case two type variables have the same sub relations root, + /// we set the `sub_root` of the second variable to the position of the first. + /// Otherwise the `sub_root` of each type variable is just its own position. + sub_root_lookup_table: FxHashMap<TyVid, usize>, canonicalize_mode: &'cx dyn CanonicalizeMode, needs_canonical_flags: TypeFlags, @@ -384,10 +390,9 @@ impl<'cx, 'db> TypeFolder<DbInterner<'db>> for Canonicalizer<'cx, 'db> { // FIXME: perf problem described in #55921. ui = UniverseIndex::ROOT; } - self.canonicalize_ty_var( - CanonicalVarKind::Ty(CanonicalTyVarKind::General(ui)), - t, - ) + + let sub_root = self.get_or_insert_sub_root(vid); + self.canonicalize_ty_var(CanonicalVarKind::Ty { ui, sub_root }, t) } } } @@ -397,7 +402,7 @@ impl<'cx, 'db> TypeFolder<DbInterner<'db>> for Canonicalizer<'cx, 'db> { if nt != t { self.fold_ty(nt) } else { - self.canonicalize_ty_var(CanonicalVarKind::Ty(CanonicalTyVarKind::Int), t) + self.canonicalize_ty_var(CanonicalVarKind::Int, t) } } TyKind::Infer(FloatVar(vid)) => { @@ -405,7 +410,7 @@ impl<'cx, 'db> TypeFolder<DbInterner<'db>> for Canonicalizer<'cx, 'db> { if nt != t { self.fold_ty(nt) } else { - self.canonicalize_ty_var(CanonicalVarKind::Ty(CanonicalTyVarKind::Float), t) + self.canonicalize_ty_var(CanonicalVarKind::Float, t) } } @@ -579,6 +584,7 @@ impl<'cx, 'db> Canonicalizer<'cx, 'db> { variables: SmallVec::from_slice(base.variables.as_slice()), query_state, indices: FxHashMap::default(), + sub_root_lookup_table: Default::default(), binder_index: DebruijnIndex::ZERO, }; if canonicalizer.query_state.var_values.spilled() { @@ -673,6 +679,13 @@ impl<'cx, 'db> Canonicalizer<'cx, 'db> { } } + fn get_or_insert_sub_root(&mut self, vid: TyVid) -> BoundVar { + let root_vid = self.infcx.sub_unification_table_root_var(vid); + let idx = + *self.sub_root_lookup_table.entry(root_vid).or_insert_with(|| self.variables.len()); + BoundVar::from(idx) + } + /// Replaces the universe indexes used in `var_values` with their index in /// `query_state.universe_map`. This minimizes the maximum universe used in /// the canonicalized value. @@ -692,9 +705,9 @@ impl<'cx, 'db> Canonicalizer<'cx, 'db> { self.variables .iter() .map(|v| match *v { - CanonicalVarKind::Ty(CanonicalTyVarKind::Int | CanonicalTyVarKind::Float) => *v, - CanonicalVarKind::Ty(CanonicalTyVarKind::General(u)) => { - CanonicalVarKind::Ty(CanonicalTyVarKind::General(reverse_universe_map[&u])) + CanonicalVarKind::Int | CanonicalVarKind::Float => *v, + CanonicalVarKind::Ty { ui, sub_root } => { + CanonicalVarKind::Ty { ui: reverse_universe_map[&ui], sub_root } } CanonicalVarKind::Region(u) => CanonicalVarKind::Region(reverse_universe_map[&u]), CanonicalVarKind::Const(u) => CanonicalVarKind::Const(reverse_universe_map[&u]), |