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Auto merge of #73180 - matthewjasper:predicate-cache, r=nikomatsakis

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Cache flags and escaping vars for predicates

With predicates becoming interned (rust-lang/compiler-team#285) this is now possible and could be a perf win. It would become an even larger win once we have recursive predicates.

cc @lcnr @nikomatsakis

r? @ghost
This commit is contained in:
bors 2020-06-21 21:05:57 +00:00
commit 1a4e2b6f9c
11 changed files with 322 additions and 101 deletions
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25
src/librustc_metadata/rmeta/decoder.rs
View file

@ -294,15 +294,36 @@ impl<'a, 'tcx> TyDecoder<'tcx> for DecodeContext<'a, 'tcx> {
let key = ty::CReaderCacheKey { cnum: self.cdata().cnum, pos: shorthand };
if let Some(&ty) = tcx.rcache.borrow().get(&key) {
if let Some(&ty) = tcx.ty_rcache.borrow().get(&key) {
return Ok(ty);
}
let ty = or_insert_with(self)?;
tcx.rcache.borrow_mut().insert(key, ty);
tcx.ty_rcache.borrow_mut().insert(key, ty);
Ok(ty)
}
fn cached_predicate_for_shorthand<F>(
&mut self,
shorthand: usize,
or_insert_with: F,
) -> Result<ty::Predicate<'tcx>, Self::Error>
where
F: FnOnce(&mut Self) -> Result<ty::Predicate<'tcx>, Self::Error>,
{
let tcx = self.tcx();
let key = ty::CReaderCacheKey { cnum: self.cdata().cnum, pos: shorthand };
if let Some(&pred) = tcx.pred_rcache.borrow().get(&key) {
return Ok(pred);
}
let pred = or_insert_with(self)?;
tcx.pred_rcache.borrow_mut().insert(key, pred);
Ok(pred)
}
fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
where
F: FnOnce(&mut Self) -> R,

27
src/librustc_metadata/rmeta/encoder.rs
View file

@ -239,6 +239,17 @@ where
}
}
impl<'b, 'tcx> SpecializedEncoder<ty::Predicate<'b>> for EncodeContext<'tcx> {
fn specialized_encode(&mut self, predicate: &ty::Predicate<'b>) -> Result<(), Self::Error> {
debug_assert!(self.tcx.lift(predicate).is_some());
let predicate =
unsafe { std::mem::transmute::<&ty::Predicate<'b>, &ty::Predicate<'tcx>>(predicate) };
ty_codec::encode_with_shorthand(self, predicate, |encoder| {
&mut encoder.predicate_shorthands
})
}
}
impl<'tcx> SpecializedEncoder<interpret::AllocId> for EncodeContext<'tcx> {
fn specialized_encode(&mut self, alloc_id: &interpret::AllocId) -> Result<(), Self::Error> {
use std::collections::hash_map::Entry;
@ -256,22 +267,6 @@ impl<'tcx> SpecializedEncoder<interpret::AllocId> for EncodeContext<'tcx> {
}
}
impl<'a, 'b, 'tcx> SpecializedEncoder<&'a [(ty::Predicate<'b>, Span)]> for EncodeContext<'tcx> {
fn specialized_encode(
&mut self,
predicates: &&'a [(ty::Predicate<'b>, Span)],
) -> Result<(), Self::Error> {
debug_assert!(self.tcx.lift(*predicates).is_some());
let predicates = unsafe {
std::mem::transmute::<
&&'a [(ty::Predicate<'b>, Span)],
&&'tcx [(ty::Predicate<'tcx>, Span)],
>(predicates)
};
ty_codec::encode_spanned_predicates(self, &predicates, |ecx| &mut ecx.predicate_shorthands)
}
}
impl<'tcx> SpecializedEncoder<Fingerprint> for EncodeContext<'tcx> {
fn specialized_encode(&mut self, f: &Fingerprint) -> Result<(), Self::Error> {
f.encode_opaque(&mut self.opaque)

1
src/librustc_middle/arena.rs
View file

@ -100,6 +100,7 @@ macro_rules! arena_types {
// Interned types
[] tys: rustc_middle::ty::TyS<$tcx>, rustc_middle::ty::TyS<'_x>;
[] predicates: rustc_middle::ty::PredicateInner<$tcx>, rustc_middle::ty::PredicateInner<'_x>;
// HIR query types
[few] indexed_hir: rustc_middle::hir::map::IndexedHir<$tcx>, rustc_middle::hir::map::IndexedHir<'_x>;

82
src/librustc_middle/ty/codec.rs
View file

@ -10,7 +10,7 @@ use crate::arena::ArenaAllocatable;
use crate::infer::canonical::{CanonicalVarInfo, CanonicalVarInfos};
use crate::mir::{self, interpret::Allocation};
use crate::ty::subst::SubstsRef;
use crate::ty::{self, List, ToPredicate, Ty, TyCtxt};
use crate::ty::{self, List, Ty, TyCtxt};
use rustc_data_structures::fx::FxHashMap;
use rustc_hir::def_id::{CrateNum, DefId};
use rustc_serialize::{opaque, Decodable, Decoder, Encodable, Encoder};
@ -95,23 +95,6 @@ where
Ok(())
}
pub fn encode_spanned_predicates<'tcx, E, C>(
encoder: &mut E,
predicates: &[(ty::Predicate<'tcx>, Span)],
cache: C,
) -> Result<(), E::Error>
where
E: TyEncoder,
C: for<'b> Fn(&'b mut E) -> &'b mut FxHashMap<ty::Predicate<'tcx>, usize>,
{
predicates.len().encode(encoder)?;
for (predicate, span) in predicates {
encode_with_shorthand(encoder, predicate, &cache)?;
span.encode(encoder)?;
}
Ok(())
}
pub trait TyDecoder<'tcx>: Decoder {
fn tcx(&self) -> TyCtxt<'tcx>;
@ -127,6 +110,14 @@ pub trait TyDecoder<'tcx>: Decoder {
where
F: FnOnce(&mut Self) -> Result<Ty<'tcx>, Self::Error>;
fn cached_predicate_for_shorthand<F>(
&mut self,
shorthand: usize,
or_insert_with: F,
) -> Result<ty::Predicate<'tcx>, Self::Error>
where
F: FnOnce(&mut Self) -> Result<ty::Predicate<'tcx>, Self::Error>;
fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
where
F: FnOnce(&mut Self) -> R;
@ -188,6 +179,26 @@ where
}
}
#[inline]
pub fn decode_predicate<D>(decoder: &mut D) -> Result<ty::Predicate<'tcx>, D::Error>
where
D: TyDecoder<'tcx>,
{
// Handle shorthands first, if we have an usize > 0x80.
if decoder.positioned_at_shorthand() {
let pos = decoder.read_usize()?;
assert!(pos >= SHORTHAND_OFFSET);
let shorthand = pos - SHORTHAND_OFFSET;
decoder.cached_predicate_for_shorthand(shorthand, |decoder| {
decoder.with_position(shorthand, ty::Predicate::decode)
})
} else {
let tcx = decoder.tcx();
Ok(tcx.mk_predicate(ty::PredicateKind::decode(decoder)?))
}
}
#[inline]
pub fn decode_spanned_predicates<D>(
decoder: &mut D,
@ -198,20 +209,7 @@ where
let tcx = decoder.tcx();
Ok(tcx.arena.alloc_from_iter(
(0..decoder.read_usize()?)
.map(|_| {
// Handle shorthands first, if we have an usize > 0x80.
let predicate_kind = if decoder.positioned_at_shorthand() {
let pos = decoder.read_usize()?;
assert!(pos >= SHORTHAND_OFFSET);
let shorthand = pos - SHORTHAND_OFFSET;
decoder.with_position(shorthand, ty::PredicateKind::decode)
} else {
ty::PredicateKind::decode(decoder)
}?;
let predicate = predicate_kind.to_predicate(tcx);
Ok((predicate, Decodable::decode(decoder)?))
})
.map(|_| Decodable::decode(decoder))
.collect::<Result<Vec<_>, _>>()?,
))
}
@ -421,7 +419,6 @@ macro_rules! implement_ty_decoder {
// FIXME(#36588): These impls are horribly unsound as they allow
// the caller to pick any lifetime for `'tcx`, including `'static`.
rustc_hir::arena_types!(impl_arena_allocatable_decoders, [$DecoderName [$($typaram),*]], 'tcx);
arena_types!(impl_arena_allocatable_decoders, [$DecoderName [$($typaram),*]], 'tcx);
impl<$($typaram),*> SpecializedDecoder<CrateNum>
@ -436,7 +433,24 @@ macro_rules! implement_ty_decoder {
where &'_x ty::TyS<'_y>: UseSpecializedDecodable
{
fn specialized_decode(&mut self) -> Result<&'_x ty::TyS<'_y>, Self::Error> {
unsafe { transmute::<Result<ty::Ty<'tcx>, Self::Error>, Result<&'_x ty::TyS<'_y>, Self::Error>>(decode_ty(self)) }
unsafe {
transmute::<
Result<ty::Ty<'tcx>, Self::Error>,
Result<&'_x ty::TyS<'_y>, Self::Error>,
>(decode_ty(self))
}
}
}
impl<'_x, $($typaram),*> SpecializedDecoder<ty::Predicate<'_x>>
for $DecoderName<$($typaram),*> {
fn specialized_decode(&mut self) -> Result<ty::Predicate<'_x>, Self::Error> {
unsafe {
transmute::<
Result<ty::Predicate<'tcx>, Self::Error>,
Result<ty::Predicate<'_x>, Self::Error>,
>(decode_predicate(self))
}
}
}

65
src/librustc_middle/ty/context.rs
View file

@ -19,8 +19,9 @@ use crate::ty::TyKind::*;
use crate::ty::{
self, query, AdtDef, AdtKind, BindingMode, BoundVar, CanonicalPolyFnSig, Const, ConstVid,
DefIdTree, ExistentialPredicate, FloatVar, FloatVid, GenericParamDefKind, InferConst, InferTy,
IntVar, IntVid, List, ParamConst, ParamTy, PolyFnSig, Predicate, PredicateKind, ProjectionTy,
Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyS, TyVar, TyVid, TypeAndMut,
IntVar, IntVid, List, ParamConst, ParamTy, PolyFnSig, Predicate, PredicateInner, PredicateKind,
ProjectionTy, Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyS, TyVar,
TyVid, TypeAndMut,
};
use rustc_ast::ast;
use rustc_ast::expand::allocator::AllocatorKind;
@ -76,7 +77,7 @@ pub struct CtxtInterners<'tcx> {
canonical_var_infos: InternedSet<'tcx, List<CanonicalVarInfo>>,
region: InternedSet<'tcx, RegionKind>,
existential_predicates: InternedSet<'tcx, List<ExistentialPredicate<'tcx>>>,
predicate_kind: InternedSet<'tcx, PredicateKind<'tcx>>,
predicate: InternedSet<'tcx, PredicateInner<'tcx>>,
predicates: InternedSet<'tcx, List<Predicate<'tcx>>>,
projs: InternedSet<'tcx, List<ProjectionKind>>,
place_elems: InternedSet<'tcx, List<PlaceElem<'tcx>>>,
@ -95,7 +96,7 @@ impl<'tcx> CtxtInterners<'tcx> {
region: Default::default(),
existential_predicates: Default::default(),
canonical_var_infos: Default::default(),
predicate_kind: Default::default(),
predicate: Default::default(),
predicates: Default::default(),
projs: Default::default(),
place_elems: Default::default(),
@ -123,6 +124,23 @@ impl<'tcx> CtxtInterners<'tcx> {
})
.0
}
#[inline(never)]
fn intern_predicate(&self, kind: PredicateKind<'tcx>) -> &'tcx PredicateInner<'tcx> {
self.predicate
.intern(kind, |kind| {
let flags = super::flags::FlagComputation::for_predicate(&kind);
let predicate_struct = PredicateInner {
kind,
flags: flags.flags,
outer_exclusive_binder: flags.outer_exclusive_binder,
};
Interned(self.arena.alloc(predicate_struct))
})
.0
}
}
pub struct CommonTypes<'tcx> {
@ -938,8 +956,9 @@ pub struct GlobalCtxt<'tcx> {
/// via `extern crate` item and not `--extern` option or compiler built-in.
pub extern_prelude: FxHashMap<Symbol, bool>,
// Internal cache for metadata decoding. No need to track deps on this.
pub rcache: Lock<FxHashMap<ty::CReaderCacheKey, Ty<'tcx>>>,
// Internal caches for metadata decoding. No need to track deps on this.
pub ty_rcache: Lock<FxHashMap<ty::CReaderCacheKey, Ty<'tcx>>>,
pub pred_rcache: Lock<FxHashMap<ty::CReaderCacheKey, Predicate<'tcx>>>,
/// Caches the results of trait selection. This cache is used
/// for things that do not have to do with the parameters in scope.
@ -1128,7 +1147,8 @@ impl<'tcx> TyCtxt<'tcx> {
definitions,
def_path_hash_to_def_id,
queries: query::Queries::new(providers, extern_providers, on_disk_query_result_cache),
rcache: Default::default(),
ty_rcache: Default::default(),
pred_rcache: Default::default(),
selection_cache: Default::default(),
evaluation_cache: Default::default(),
crate_name: Symbol::intern(crate_name),
@ -1625,7 +1645,7 @@ macro_rules! nop_list_lift {
nop_lift! {type_; Ty<'a> => Ty<'tcx>}
nop_lift! {region; Region<'a> => Region<'tcx>}
nop_lift! {const_; &'a Const<'a> => &'tcx Const<'tcx>}
nop_lift! {predicate_kind; &'a PredicateKind<'a> => &'tcx PredicateKind<'tcx>}
nop_lift! {predicate; &'a PredicateInner<'a> => &'tcx PredicateInner<'tcx>}
nop_list_lift! {type_list; Ty<'a> => Ty<'tcx>}
nop_list_lift! {existential_predicates; ExistentialPredicate<'a> => ExistentialPredicate<'tcx>}
@ -1984,6 +2004,26 @@ impl<'tcx> Borrow<TyKind<'tcx>> for Interned<'tcx, TyS<'tcx>> {
&self.0.kind
}
}
// N.B., an `Interned<PredicateInner>` compares and hashes as a `PredicateKind`.
impl<'tcx> PartialEq for Interned<'tcx, PredicateInner<'tcx>> {
fn eq(&self, other: &Interned<'tcx, PredicateInner<'tcx>>) -> bool {
self.0.kind == other.0.kind
}
}
impl<'tcx> Eq for Interned<'tcx, PredicateInner<'tcx>> {}
impl<'tcx> Hash for Interned<'tcx, PredicateInner<'tcx>> {
fn hash<H: Hasher>(&self, s: &mut H) {
self.0.kind.hash(s)
}
}
impl<'tcx> Borrow<PredicateKind<'tcx>> for Interned<'tcx, PredicateInner<'tcx>> {
fn borrow<'a>(&'a self) -> &'a PredicateKind<'tcx> {
&self.0.kind
}
}
// N.B., an `Interned<List<T>>` compares and hashes as its elements.
impl<'tcx, T: PartialEq> PartialEq for Interned<'tcx, List<T>> {
@ -2050,11 +2090,10 @@ macro_rules! direct_interners {
}
}
direct_interners!(
direct_interners! {
region: mk_region(RegionKind),
const_: mk_const(Const<'tcx>),
predicate_kind: intern_predicate_kind(PredicateKind<'tcx>),
);
}
macro_rules! slice_interners {
($($field:ident: $method:ident($ty:ty)),+) => (
@ -2125,8 +2164,8 @@ impl<'tcx> TyCtxt<'tcx> {
#[inline]
pub fn mk_predicate(&self, kind: PredicateKind<'tcx>) -> Predicate<'tcx> {
let kind = self.intern_predicate_kind(kind);
Predicate { kind }
let inner = self.interners.intern_predicate(kind);
Predicate { inner }
}
pub fn mk_mach_int(self, tm: ast::IntTy) -> Ty<'tcx> {

82
src/librustc_middle/ty/flags.rs
View file

@ -1,5 +1,6 @@
use crate::ty::subst::{GenericArg, GenericArgKind};
use crate::ty::{self, InferConst, Ty, TypeFlags};
use std::slice;
#[derive(Debug)]
pub struct FlagComputation {
@ -21,6 +22,12 @@ impl FlagComputation {
result
}
pub fn for_predicate(kind: &ty::PredicateKind<'_>) -> FlagComputation {
let mut result = FlagComputation::new();
result.add_predicate_kind(kind);
result
}
pub fn for_const(c: &ty::Const<'_>) -> TypeFlags {
let mut result = FlagComputation::new();
result.add_const(c);
@ -32,7 +39,7 @@ impl FlagComputation {
}
/// indicates that `self` refers to something at binding level `binder`
fn add_binder(&mut self, binder: ty::DebruijnIndex) {
fn add_bound_var(&mut self, binder: ty::DebruijnIndex) {
let exclusive_binder = binder.shifted_in(1);
self.add_exclusive_binder(exclusive_binder);
}
@ -46,7 +53,7 @@ impl FlagComputation {
/// Adds the flags/depth from a set of types that appear within the current type, but within a
/// region binder.
fn add_bound_computation(&mut self, computation: &FlagComputation) {
fn add_bound_computation(&mut self, computation: FlagComputation) {
self.add_flags(computation.flags);
// The types that contributed to `computation` occurred within
@ -84,7 +91,7 @@ impl FlagComputation {
&ty::GeneratorWitness(ref ts) => {
let mut computation = FlagComputation::new();
computation.add_tys(&ts.skip_binder()[..]);
self.add_bound_computation(&computation);
self.add_bound_computation(computation);
}
&ty::Closure(_, ref substs) => {
@ -92,7 +99,7 @@ impl FlagComputation {
}
&ty::Bound(debruijn, _) => {
self.add_binder(debruijn);
self.add_bound_var(debruijn);
}
&ty::Placeholder(..) => {
@ -133,12 +140,12 @@ impl FlagComputation {
ty::ExistentialPredicate::Projection(p) => {
let mut proj_computation = FlagComputation::new();
proj_computation.add_existential_projection(&p);
self.add_bound_computation(&proj_computation);
self.add_bound_computation(proj_computation);
}
ty::ExistentialPredicate::AutoTrait(_) => {}
}
}
self.add_bound_computation(&computation);
self.add_bound_computation(computation);
self.add_region(r);
}
@ -172,6 +179,63 @@ impl FlagComputation {
}
}
fn add_predicate_kind(&mut self, kind: &ty::PredicateKind<'_>) {
match kind {
ty::PredicateKind::Trait(trait_pred, _constness) => {
let mut computation = FlagComputation::new();
computation.add_substs(trait_pred.skip_binder().trait_ref.substs);
self.add_bound_computation(computation);
}
ty::PredicateKind::RegionOutlives(poly_outlives) => {
let mut computation = FlagComputation::new();
let ty::OutlivesPredicate(a, b) = poly_outlives.skip_binder();
computation.add_region(a);
computation.add_region(b);
self.add_bound_computation(computation);
}
ty::PredicateKind::TypeOutlives(poly_outlives) => {
let mut computation = FlagComputation::new();
let ty::OutlivesPredicate(ty, region) = poly_outlives.skip_binder();
computation.add_ty(ty);
computation.add_region(region);
self.add_bound_computation(computation);
}
ty::PredicateKind::Subtype(poly_subtype) => {
let mut computation = FlagComputation::new();
let ty::SubtypePredicate { a_is_expected: _, a, b } = poly_subtype.skip_binder();
computation.add_ty(a);
computation.add_ty(b);
self.add_bound_computation(computation);
}
ty::PredicateKind::Projection(projection) => {
let mut computation = FlagComputation::new();
let ty::ProjectionPredicate { projection_ty, ty } = projection.skip_binder();
computation.add_projection_ty(projection_ty);
computation.add_ty(ty);
self.add_bound_computation(computation);
}
ty::PredicateKind::WellFormed(arg) => {
self.add_substs(slice::from_ref(arg));
}
ty::PredicateKind::ObjectSafe(_def_id) => {}
ty::PredicateKind::ClosureKind(_def_id, substs, _kind) => {
self.add_substs(substs);
}
ty::PredicateKind::ConstEvaluatable(_def_id, substs) => {
self.add_substs(substs);
}
ty::PredicateKind::ConstEquate(expected, found) => {
self.add_const(expected);
self.add_const(found);
}
}
}
fn add_ty(&mut self, ty: Ty<'_>) {
self.add_flags(ty.flags);
self.add_exclusive_binder(ty.outer_exclusive_binder);
@ -189,13 +253,13 @@ impl FlagComputation {
computation.add_tys(fn_sig.skip_binder().inputs());
computation.add_ty(fn_sig.skip_binder().output());
self.add_bound_computation(&computation);
self.add_bound_computation(computation);
}
fn add_region(&mut self, r: ty::Region<'_>) {
self.add_flags(r.type_flags());
if let ty::ReLateBound(debruijn, _) = *r {
self.add_binder(debruijn);
self.add_bound_var(debruijn);
}
}
@ -214,7 +278,7 @@ impl FlagComputation {
}
}
ty::ConstKind::Bound(debruijn, _) => {
self.add_binder(debruijn);
self.add_bound_var(debruijn);
}
ty::ConstKind::Param(_) => {
self.add_flags(TypeFlags::HAS_CT_PARAM);

16
src/librustc_middle/ty/fold.rs
View file

@ -31,6 +31,7 @@
//! These methods return true to indicate that the visitor has found what it is
//! looking for, and does not need to visit anything else.
use crate::ty::structural_impls::PredicateVisitor;
use crate::ty::{self, flags::FlagComputation, Binder, Ty, TyCtxt, TypeFlags};
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
@ -908,6 +909,12 @@ impl<'tcx> TypeVisitor<'tcx> for HasEscapingVarsVisitor {
}
}
impl<'tcx> PredicateVisitor<'tcx> for HasEscapingVarsVisitor {
fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool {
predicate.inner.outer_exclusive_binder > self.outer_index
}
}
// FIXME: Optimize for checking for infer flags
struct HasTypeFlagsVisitor {
flags: ty::TypeFlags,
@ -932,6 +939,15 @@ impl<'tcx> TypeVisitor<'tcx> for HasTypeFlagsVisitor {
}
}
impl<'tcx> PredicateVisitor<'tcx> for HasTypeFlagsVisitor {
fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool {
debug!(
"HasTypeFlagsVisitor: predicate={:?} predicate.flags={:?} self.flags={:?}",
predicate, predicate.inner.flags, self.flags
);
predicate.inner.flags.intersects(self.flags)
}
}
/// Collects all the late-bound regions at the innermost binding level
/// into a hash set.
struct LateBoundRegionsCollector {

48
src/librustc_middle/ty/mod.rs
View file

@ -627,7 +627,7 @@ impl<'tcx> Hash for TyS<'tcx> {
}
}
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ty::TyS<'tcx> {
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for TyS<'tcx> {
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
let ty::TyS {
ref kind,
@ -1001,16 +1001,35 @@ impl<'tcx> GenericPredicates<'tcx> {
}
}
#[derive(Clone, Copy, Hash, RustcEncodable, RustcDecodable, Lift)]
#[derive(HashStable)]
pub struct Predicate<'tcx> {
kind: &'tcx PredicateKind<'tcx>,
#[derive(Debug)]
crate struct PredicateInner<'tcx> {
kind: PredicateKind<'tcx>,
flags: TypeFlags,
/// See the comment for the corresponding field of [TyS].
outer_exclusive_binder: ty::DebruijnIndex,
}
#[cfg(target_arch = "x86_64")]
static_assert_size!(PredicateInner<'_>, 40);
#[derive(Clone, Copy, Lift)]
pub struct Predicate<'tcx> {
inner: &'tcx PredicateInner<'tcx>,
}
impl rustc_serialize::UseSpecializedEncodable for Predicate<'_> {}
impl rustc_serialize::UseSpecializedDecodable for Predicate<'_> {}
impl<'tcx> PartialEq for Predicate<'tcx> {
fn eq(&self, other: &Self) -> bool {
// `self.kind` is always interned.
ptr::eq(self.kind, other.kind)
ptr::eq(self.inner, other.inner)
}
}
impl Hash for Predicate<'_> {
fn hash<H: Hasher>(&self, s: &mut H) {
(self.inner as *const PredicateInner<'_>).hash(s)
}
}
@ -1019,7 +1038,22 @@ impl<'tcx> Eq for Predicate<'tcx> {}
impl<'tcx> Predicate<'tcx> {
#[inline(always)]
pub fn kind(self) -> &'tcx PredicateKind<'tcx> {
self.kind
&self.inner.kind
}
}
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Predicate<'tcx> {
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
let PredicateInner {
ref kind,
// The other fields just provide fast access to information that is
// also contained in `kind`, so no need to hash them.
flags: _,
outer_exclusive_binder: _,
} = self.inner;
kind.hash_stable(hcx, hasher);
}
}

47
src/librustc_middle/ty/query/on_disk_cache.rs
View file

@ -524,16 +524,39 @@ impl<'a, 'tcx> TyDecoder<'tcx> for CacheDecoder<'a, 'tcx> {
let cache_key =
ty::CReaderCacheKey { cnum: CrateNum::ReservedForIncrCompCache, pos: shorthand };
if let Some(&ty) = tcx.rcache.borrow().get(&cache_key) {
if let Some(&ty) = tcx.ty_rcache.borrow().get(&cache_key) {
return Ok(ty);
}
let ty = or_insert_with(self)?;
// This may overwrite the entry, but it should overwrite with the same value.
tcx.rcache.borrow_mut().insert_same(cache_key, ty);
tcx.ty_rcache.borrow_mut().insert_same(cache_key, ty);
Ok(ty)
}
fn cached_predicate_for_shorthand<F>(
&mut self,
shorthand: usize,
or_insert_with: F,
) -> Result<ty::Predicate<'tcx>, Self::Error>
where
F: FnOnce(&mut Self) -> Result<ty::Predicate<'tcx>, Self::Error>,
{
let tcx = self.tcx();
let cache_key =
ty::CReaderCacheKey { cnum: CrateNum::ReservedForIncrCompCache, pos: shorthand };
if let Some(&pred) = tcx.pred_rcache.borrow().get(&cache_key) {
return Ok(pred);
}
let pred = or_insert_with(self)?;
// This may overwrite the entry, but it should overwrite with the same value.
tcx.pred_rcache.borrow_mut().insert_same(cache_key, pred);
Ok(pred)
}
fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
where
F: FnOnce(&mut Self) -> R,
@ -820,24 +843,16 @@ where
}
}
impl<'a, 'b, 'c, 'tcx, E> SpecializedEncoder<&'b [(ty::Predicate<'c>, Span)]>
for CacheEncoder<'a, 'tcx, E>
impl<'a, 'b, 'tcx, E> SpecializedEncoder<ty::Predicate<'b>> for CacheEncoder<'a, 'tcx, E>
where
E: 'a + TyEncoder,
{
#[inline]
fn specialized_encode(
&mut self,
predicates: &&'b [(ty::Predicate<'c>, Span)],
) -> Result<(), Self::Error> {
debug_assert!(self.tcx.lift(*predicates).is_some());
let predicates = unsafe {
std::mem::transmute::<
&&'b [(ty::Predicate<'c>, Span)],
&&'tcx [(ty::Predicate<'tcx>, Span)],
>(predicates)
};
ty_codec::encode_spanned_predicates(self, predicates, |encoder| {
fn specialized_encode(&mut self, predicate: &ty::Predicate<'b>) -> Result<(), Self::Error> {
debug_assert!(self.tcx.lift(predicate).is_some());
let predicate =
unsafe { std::mem::transmute::<&ty::Predicate<'b>, &ty::Predicate<'tcx>>(predicate) };
ty_codec::encode_with_shorthand(self, predicate, |encoder| {
&mut encoder.predicate_shorthands
})
}

28
src/librustc_middle/ty/structural_impls.rs
View file

@ -987,12 +987,34 @@ impl<'tcx> TypeFoldable<'tcx> for ty::Region<'tcx> {
impl<'tcx> TypeFoldable<'tcx> for ty::Predicate<'tcx> {
fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
let new = ty::PredicateKind::super_fold_with(self.kind, folder);
if new != *self.kind { folder.tcx().mk_predicate(new) } else { *self }
let new = ty::PredicateKind::super_fold_with(&self.inner.kind, folder);
if new != self.inner.kind { folder.tcx().mk_predicate(new) } else { *self }
}
fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
ty::PredicateKind::super_visit_with(self.kind, visitor)
ty::PredicateKind::super_visit_with(&self.inner.kind, visitor)
}
fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
visitor.visit_predicate(*self)
}
fn has_vars_bound_at_or_above(&self, binder: ty::DebruijnIndex) -> bool {
self.inner.outer_exclusive_binder > binder
}
fn has_type_flags(&self, flags: ty::TypeFlags) -> bool {
self.inner.flags.intersects(flags)
}
}
pub(super) trait PredicateVisitor<'tcx>: TypeVisitor<'tcx> {
fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool;
}
impl<T: TypeVisitor<'tcx>> PredicateVisitor<'tcx> for T {
default fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool {
predicate.super_visit_with(self)
}
}

2
src/librustc_trait_selection/traits/fulfill.rs
View file

@ -321,7 +321,7 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
ty::PredicateKind::Trait(ref data, _) => {
let trait_obligation = obligation.with(*data);
if data.is_global() {
if obligation.predicate.is_global() {
// no type variables present, can use evaluation for better caching.
// FIXME: consider caching errors too.
if infcx.predicate_must_hold_considering_regions(&obligation) {