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Rollup merge of #113887 - lcnr:cache-coherence, r=compiler-errors

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new solver: add a separate cache for coherence

based on #113835

`typenum` now compiles with `-Ztrait-solver=next-coherence`. Because we disable caching once we encounter the recursion limit it is still really slow, but at least it passes and I will deal with overflow handling afterwards.

`typenum` previously hanged. The top 10 goals were
```rust
1749948 counts
(  1)   601056 (34.3%, 34.3%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: ProjectionPredicate(AliasTy { args: [^1_0], def_id: DefId(0:1196 ~ typenum[0ab6]::type_operators::Len::Output) }, Term::Ty(^1_1)), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }, CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  2)   240422 (13.7%, 48.1%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: ProjectionPredicate(AliasTy { args: [<^1_0 as type_operators::Len>::Output, bit::B1], def_id: DefId(1:2752 ~ core[a405]::ops::arith::Add::Output) }, Term::Ty(^1_1)), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }, CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  3)   198367 (11.3%, 59.4%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<^1_0 as core::marker::Sized>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  4)    96168 ( 5.5%, 64.9%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: ProjectionPredicate(AliasTy { args: [<^1_0 as type_operators::Len>::Output, bit::B1], def_id: DefId(1:2752 ~ core[a405]::ops::arith::Add::Output) }, Term::Ty(<<^1_0 as type_operators::Len>::Output as core::ops::Add<bit::B1>>::Output)), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  5)    78155 ( 4.5%, 69.4%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<^1_0 as marker_traits::Unsigned>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  6)    72140 ( 4.1%, 73.5%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<^1_0 as marker_traits::Bit>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  7)    60107 ( 3.4%, 76.9%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<^1_0 as type_operators::Len>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  8)    60106 ( 3.4%, 80.4%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: ProjectionPredicate(AliasTy { args: [uint::UInt<^1_0, ^1_1>], def_id: DefId(0:1196 ~ typenum[0ab6]::type_operators::Len::Output) }, Term::Ty(^1_2)), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }, CanonicalVarInfo { kind: Ty(General(U0)) }, CanonicalVarInfo { kind: Ty(General(U0)) }] }
(  9)    60106 ( 3.4%, 83.8%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<<<^1_0 as type_operators::Len>::Output as core::ops::Add<bit::B1>>::Output as marker_traits::Unsigned>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }] }
( 10)    60106 ( 3.4%, 87.2%): Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<<^1_0 as type_operators::Len>::Output as core::ops::Add<bit::B1>>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst } }, anchor: Bubble, predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [CanonicalVarInfo { kind: Ty(General(U0)) }] }
```

r? ``@compiler-errors``
This commit is contained in:
Matthias Krüger 2023-07-21 17:17:41 +02:00 committed by GitHub
commit af1e082200
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 20 additions and 17 deletions
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12
compiler/rustc_middle/src/ty/context.rs
View File

@ -569,6 +569,7 @@ pub struct GlobalCtxt<'tcx> {
/// Caches the results of goal evaluation in the new solver.
pub new_solver_evaluation_cache: solve::EvaluationCache<'tcx>,
pub new_solver_coherence_evaluation_cache: solve::EvaluationCache<'tcx>,
/// Data layout specification for the current target.
pub data_layout: TargetDataLayout,
@ -680,10 +681,12 @@ impl<'tcx> TyCtxt<'tcx> {
value.lift_to_tcx(self)
}
/// Creates a type context and call the closure with a `TyCtxt` reference
/// to the context. The closure enforces that the type context and any interned
/// value (types, args, etc.) can only be used while `ty::tls` has a valid
/// reference to the context, to allow formatting values that need it.
/// Creates a type context. To use the context call `fn enter` which
/// provides a `TyCtxt`.
///
/// By only providing the `TyCtxt` inside of the closure we enforce that the type
/// context and any interned alue (types, args, etc.) can only be used while `ty::tls`
/// has a valid reference to the context, to allow formatting values that need it.
pub fn create_global_ctxt(
s: &'tcx Session,
lint_store: Lrc<dyn Any + sync::DynSend + sync::DynSync>,
@ -721,6 +724,7 @@ impl<'tcx> TyCtxt<'tcx> {
selection_cache: Default::default(),
evaluation_cache: Default::default(),
new_solver_evaluation_cache: Default::default(),
new_solver_coherence_evaluation_cache: Default::default(),
data_layout,
alloc_map: Lock::new(interpret::AllocMap::new()),
}

25
compiler/rustc_trait_selection/src/solve/search_graph/mod.rs
View File

@ -9,7 +9,9 @@ use cache::ProvisionalCache;
use overflow::OverflowData;
use rustc_index::IndexVec;
use rustc_middle::dep_graph::DepKind;
use rustc_middle::traits::solve::{CanonicalInput, Certainty, MaybeCause, QueryResult};
use rustc_middle::traits::solve::{
CanonicalInput, Certainty, EvaluationCache, MaybeCause, QueryResult,
};
use rustc_middle::ty::TyCtxt;
use std::{collections::hash_map::Entry, mem};
@ -58,10 +60,10 @@ impl<'tcx> SearchGraph<'tcx> {
///
/// We could add another global cache for coherence instead,
/// but that's effort so let's only do it if necessary.
pub(super) fn should_use_global_cache(&self) -> bool {
pub(super) fn global_cache(&self, tcx: TyCtxt<'tcx>) -> &'tcx EvaluationCache<'tcx> {
match self.mode {
SolverMode::Normal => true,
SolverMode::Coherence => false,
SolverMode::Normal => &tcx.new_solver_evaluation_cache,
SolverMode::Coherence => &tcx.new_solver_coherence_evaluation_cache,
}
}
@ -213,8 +215,8 @@ impl<'tcx> SearchGraph<'tcx> {
inspect: &mut ProofTreeBuilder<'tcx>,
mut loop_body: impl FnMut(&mut Self, &mut ProofTreeBuilder<'tcx>) -> QueryResult<'tcx>,
) -> QueryResult<'tcx> {
if self.should_use_global_cache() && inspect.use_global_cache() {
if let Some(result) = tcx.new_solver_evaluation_cache.get(&canonical_input, tcx) {
if inspect.use_global_cache() {
if let Some(result) = self.global_cache(tcx).get(&canonical_input, tcx) {
debug!(?canonical_input, ?result, "cache hit");
inspect.cache_hit(CacheHit::Global);
return result;
@ -278,13 +280,10 @@ impl<'tcx> SearchGraph<'tcx> {
// dependencies, our non-root goal may no longer appear as child of the root goal.
//
// See https://github.com/rust-lang/rust/pull/108071 for some additional context.
let can_cache = !self.overflow_data.did_overflow() || self.stack.is_empty();
if self.should_use_global_cache() && can_cache {
tcx.new_solver_evaluation_cache.insert(
current_goal.input,
dep_node,
current_goal.response,
);
let can_cache = inspect.use_global_cache()
&& (!self.overflow_data.did_overflow() || self.stack.is_empty());
if can_cache {
self.global_cache(tcx).insert(current_goal.input, dep_node, current_goal.response)
}
}