Skip to content

[perf] Keep regions in canonical param-envs in new solver #142733

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

[perf] Keep regions in canonical param-envs in new solver #142733

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
48 changes: 17 additions & 31 deletions compiler/rustc_next_trait_solver/src/canonicalizer.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,7 @@ enum CanonicalizeMode {
/// When canonicalizing the `param_env`, we keep `'static` as merging
/// trait candidates relies on it when deciding whether a where-bound
/// is trivial.
Input { keep_static: bool },
Input { keep_regions: bool },
/// FIXME: We currently return region constraints referring to
/// placeholders and inference variables from a binder instantiated
/// inside of the query.
Expand Down Expand Up @@ -124,7 +124,7 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
let mut variables = Vec::new();
let mut env_canonicalizer = Canonicalizer {
delegate,
canonicalize_mode: CanonicalizeMode::Input { keep_static: true },
canonicalize_mode: CanonicalizeMode::Input { keep_regions: true },

variables: &mut variables,
variable_lookup_table: Default::default(),
Expand Down Expand Up @@ -156,7 +156,7 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
} else {
let mut env_canonicalizer = Canonicalizer {
delegate,
canonicalize_mode: CanonicalizeMode::Input { keep_static: true },
canonicalize_mode: CanonicalizeMode::Input { keep_regions: true },

variables,
variable_lookup_table: Default::default(),
Expand Down Expand Up @@ -191,7 +191,7 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
// while *mostly* reusing the canonicalizer from above.
let mut rest_canonicalizer = Canonicalizer {
delegate,
canonicalize_mode: CanonicalizeMode::Input { keep_static: false },
canonicalize_mode: CanonicalizeMode::Input { keep_regions: false },

variables,
variable_lookup_table,
Expand Down Expand Up @@ -504,35 +504,21 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz
let kind = match r.kind() {
ty::ReBound(..) => return r,

// We don't canonicalize `ReStatic` in the `param_env` as we use it
// when checking whether a `ParamEnv` candidate is global.
ty::ReStatic => match self.canonicalize_mode {
CanonicalizeMode::Input { keep_static: false } => {
// We don't canonicalize free regions in the param-env as an optimization,
// and because we use `'static` when checking whether a `ParamEnv` candidate
// is global, which affect candidate assembly.
ty::ReStatic
| ty::ReErased
| ty::ReError(_)
| ty::ReEarlyParam(_)
| ty::ReLateParam(_) => match self.canonicalize_mode {
CanonicalizeMode::Input { keep_regions: false } => {
CanonicalVarKind::Region(ty::UniverseIndex::ROOT)
}
CanonicalizeMode::Input { keep_static: true }
CanonicalizeMode::Input { keep_regions: true }
| CanonicalizeMode::Response { .. } => return r,
},

// `ReErased` should only be encountered in the hidden
// type of an opaque for regions that are ignored for the purposes of
// captures.
//
// FIXME: We should investigate the perf implications of not uniquifying
// `ReErased`. We may be able to short-circuit registering region
// obligations if we encounter a `ReErased` on one side, for example.
ty::ReErased | ty::ReError(_) => match self.canonicalize_mode {
CanonicalizeMode::Input { .. } => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
CanonicalizeMode::Response { .. } => return r,
},

ty::ReEarlyParam(_) | ty::ReLateParam(_) => match self.canonicalize_mode {
CanonicalizeMode::Input { .. } => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
CanonicalizeMode::Response { .. } => {
panic!("unexpected region in response: {r:?}")
}
},

ty::RePlaceholder(placeholder) => match self.canonicalize_mode {
// We canonicalize placeholder regions as existentials in query inputs.
CanonicalizeMode::Input { .. } => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
Expand All @@ -553,7 +539,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz
"region vid should have been resolved fully before canonicalization"
);
match self.canonicalize_mode {
CanonicalizeMode::Input { keep_static: _ } => {
CanonicalizeMode::Input { keep_regions: _ } => {
CanonicalVarKind::Region(ty::UniverseIndex::ROOT)
}
CanonicalizeMode::Response { .. } => {
Expand Down Expand Up @@ -627,9 +613,9 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz

fn fold_clauses(&mut self, c: I::Clauses) -> I::Clauses {
match self.canonicalize_mode {
CanonicalizeMode::Input { keep_static: true }
CanonicalizeMode::Input { keep_regions: true }
| CanonicalizeMode::Response { max_input_universe: _ } => {}
CanonicalizeMode::Input { keep_static: false } => {
CanonicalizeMode::Input { keep_regions: false } => {
panic!("erasing 'static in env")
}
}
Expand Down
5 changes: 2 additions & 3 deletions compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1101,9 +1101,8 @@ where
ControlFlow::Continue(())
}
}
ty::ReVar(_) => ControlFlow::Break(Ok(())),
ty::ReErased | ty::ReEarlyParam(_) | ty::ReLateParam(_) => {
unreachable!("unexpected region in param-env clause")
ty::ReVar(_) | ty::ReEarlyParam(_) | ty::ReLateParam(_) | ty::ReErased => {
ControlFlow::Break(Ok(()))
}
}
}
Expand Down
Loading