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Rollup merge of #104898 - oli-obk:group_all_the_things, r=wesleywiser
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Put all cached values into a central struct instead of just the stable hash

cc `@nnethercote`

this allows re-use of the type for Predicate without duplicating all the logic for the non-hash cached fields
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matthiaskrgr authored Dec 6, 2022
2 parents b685242 + 14a9cf2 commit db416ea
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Showing 10 changed files with 182 additions and 254 deletions.
83 changes: 0 additions & 83 deletions compiler/rustc_data_structures/src/intern.rs
Original file line number Diff line number Diff line change
Expand Up @@ -4,8 +4,6 @@ use std::hash::{Hash, Hasher};
use std::ops::Deref;
use std::ptr;

use crate::fingerprint::Fingerprint;

mod private {
#[derive(Clone, Copy, Debug)]
pub struct PrivateZst;
Expand Down Expand Up @@ -110,86 +108,5 @@ where
}
}

/// A helper type that you can wrap round your own type in order to automatically
/// cache the stable hash on creation and not recompute it whenever the stable hash
/// of the type is computed.
/// This is only done in incremental mode. You can also opt out of caching by using
/// StableHash::ZERO for the hash, in which case the hash gets computed each time.
/// This is useful if you have values that you intern but never (can?) use for stable
/// hashing.
#[derive(Copy, Clone)]
pub struct WithStableHash<T> {
pub internee: T,
pub stable_hash: Fingerprint,
}

impl<T: PartialEq> PartialEq for WithStableHash<T> {
#[inline]
fn eq(&self, other: &Self) -> bool {
self.internee.eq(&other.internee)
}
}

impl<T: Eq> Eq for WithStableHash<T> {}

impl<T: Ord> PartialOrd for WithStableHash<T> {
fn partial_cmp(&self, other: &WithStableHash<T>) -> Option<Ordering> {
Some(self.internee.cmp(&other.internee))
}
}

impl<T: Ord> Ord for WithStableHash<T> {
fn cmp(&self, other: &WithStableHash<T>) -> Ordering {
self.internee.cmp(&other.internee)
}
}

impl<T> Deref for WithStableHash<T> {
type Target = T;

#[inline]
fn deref(&self) -> &T {
&self.internee
}
}

impl<T: Hash> Hash for WithStableHash<T> {
#[inline]
fn hash<H: Hasher>(&self, s: &mut H) {
if self.stable_hash != Fingerprint::ZERO {
self.stable_hash.hash(s)
} else {
self.internee.hash(s)
}
}
}

impl<T: HashStable<CTX>, CTX> HashStable<CTX> for WithStableHash<T> {
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
if self.stable_hash == Fingerprint::ZERO || cfg!(debug_assertions) {
// No cached hash available. This can only mean that incremental is disabled.
// We don't cache stable hashes in non-incremental mode, because they are used
// so rarely that the performance actually suffers.

// We need to build the hash as if we cached it and then hash that hash, as
// otherwise the hashes will differ between cached and non-cached mode.
let stable_hash: Fingerprint = {
let mut hasher = StableHasher::new();
self.internee.hash_stable(hcx, &mut hasher);
hasher.finish()
};
if cfg!(debug_assertions) && self.stable_hash != Fingerprint::ZERO {
assert_eq!(
stable_hash, self.stable_hash,
"cached stable hash does not match freshly computed stable hash"
);
}
stable_hash.hash_stable(hcx, hasher);
} else {
self.stable_hash.hash_stable(hcx, hasher);
}
}
}

#[cfg(test)]
mod tests;
2 changes: 1 addition & 1 deletion compiler/rustc_lint/src/pass_by_value.rs
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ declare_tool_lint! {
/// The `rustc_pass_by_value` lint marks a type with `#[rustc_pass_by_value]` requiring it to
/// always be passed by value. This is usually used for types that are thin wrappers around
/// references, so there is no benefit to an extra layer of indirection. (Example: `Ty` which
/// is a reference to an `Interned<TyS>`)
/// is a reference to an `Interned<TyKind>`)
pub rustc::PASS_BY_VALUE,
Warn,
"pass by reference of a type flagged as `#[rustc_pass_by_value]`",
Expand Down
6 changes: 4 additions & 2 deletions compiler/rustc_middle/src/arena.rs
Original file line number Diff line number Diff line change
@@ -1,3 +1,5 @@
#![allow(rustc::usage_of_ty_tykind)]

/// This higher-order macro declares a list of types which can be allocated by `Arena`.
///
/// Specifying the `decode` modifier will add decode impls for `&T` and `&[T]` where `T` is the type
Expand Down Expand Up @@ -89,8 +91,8 @@ macro_rules! arena_types {
[] hir_id_set: rustc_hir::HirIdSet,

// Interned types
[] tys: rustc_data_structures::intern::WithStableHash<rustc_middle::ty::TyS<'tcx>>,
[] predicates: rustc_data_structures::intern::WithStableHash<rustc_middle::ty::PredicateS<'tcx>>,
[] tys: rustc_type_ir::WithCachedTypeInfo<rustc_middle::ty::TyKind<'tcx>>,
[] predicates: rustc_type_ir::WithCachedTypeInfo<rustc_middle::ty::PredicateKind<'tcx>>,
[] consts: rustc_middle::ty::ConstS<'tcx>,

// Note that this deliberately duplicates items in the `rustc_hir::arena`,
Expand Down
2 changes: 1 addition & 1 deletion compiler/rustc_middle/src/mir/interpret/allocation.rs
Original file line number Diff line number Diff line change
Expand Up @@ -103,7 +103,7 @@ impl hash::Hash for Allocation {
/// Interned types generally have an `Outer` type and an `Inner` type, where
/// `Outer` is a newtype around `Interned<Inner>`, and all the operations are
/// done on `Outer`, because all occurrences are interned. E.g. `Ty` is an
/// outer type and `TyS` is its inner type.
/// outer type and `TyKind` is its inner type.
///
/// Here things are different because only const allocations are interned. This
/// means that both the inner type (`Allocation`) and the outer type
Expand Down
83 changes: 27 additions & 56 deletions compiler/rustc_middle/src/ty/context.rs
Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
//! Type context book-keeping.

#![allow(rustc::usage_of_ty_tykind)]

use crate::arena::Arena;
use crate::dep_graph::{DepGraph, DepKindStruct};
use crate::hir::place::Place as HirPlace;
Expand All @@ -19,15 +21,15 @@ use crate::ty::{
self, AdtDef, AdtDefData, AdtKind, Binder, BindingMode, BoundVar, CanonicalPolyFnSig,
ClosureSizeProfileData, Const, ConstS, DefIdTree, FloatTy, FloatVar, FloatVid,
GenericParamDefKind, InferTy, IntTy, IntVar, IntVid, List, ParamConst, ParamTy,
PolyExistentialPredicate, PolyFnSig, Predicate, PredicateKind, PredicateS, ProjectionTy,
Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyS, TyVar, TyVid, TypeAndMut,
UintTy, Visibility,
PolyExistentialPredicate, PolyFnSig, Predicate, PredicateKind, ProjectionTy, Region,
RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyVar, TyVid, TypeAndMut, UintTy,
Visibility,
};
use crate::ty::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef, UserSubsts};
use rustc_ast as ast;
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::intern::{Interned, WithStableHash};
use rustc_data_structures::intern::Interned;
use rustc_data_structures::memmap::Mmap;
use rustc_data_structures::profiling::SelfProfilerRef;
use rustc_data_structures::sharded::{IntoPointer, ShardedHashMap};
Expand Down Expand Up @@ -68,6 +70,7 @@ use rustc_span::{Span, DUMMY_SP};
use rustc_target::abi::{Layout, LayoutS, TargetDataLayout, VariantIdx};
use rustc_target::spec::abi;
use rustc_type_ir::sty::TyKind::*;
use rustc_type_ir::WithCachedTypeInfo;
use rustc_type_ir::{DynKind, InternAs, InternIteratorElement, Interner, TypeFlags};

use std::any::Any;
Expand Down Expand Up @@ -137,13 +140,13 @@ pub struct CtxtInterners<'tcx> {

// Specifically use a speedy hash algorithm for these hash sets, since
// they're accessed quite often.
type_: InternedSet<'tcx, WithStableHash<TyS<'tcx>>>,
type_: InternedSet<'tcx, WithCachedTypeInfo<TyKind<'tcx>>>,
const_lists: InternedSet<'tcx, List<ty::Const<'tcx>>>,
substs: InternedSet<'tcx, InternalSubsts<'tcx>>,
canonical_var_infos: InternedSet<'tcx, List<CanonicalVarInfo<'tcx>>>,
region: InternedSet<'tcx, RegionKind<'tcx>>,
poly_existential_predicates: InternedSet<'tcx, List<PolyExistentialPredicate<'tcx>>>,
predicate: InternedSet<'tcx, WithStableHash<PredicateS<'tcx>>>,
predicate: InternedSet<'tcx, WithCachedTypeInfo<ty::Binder<'tcx, PredicateKind<'tcx>>>>,
predicates: InternedSet<'tcx, List<Predicate<'tcx>>>,
projs: InternedSet<'tcx, List<ProjectionKind>>,
place_elems: InternedSet<'tcx, List<PlaceElem<'tcx>>>,
Expand Down Expand Up @@ -194,15 +197,12 @@ impl<'tcx> CtxtInterners<'tcx> {
let stable_hash =
self.stable_hash(&flags, sess, definitions, cstore, source_span, &kind);

let ty_struct = TyS {
kind,
InternedInSet(self.arena.alloc(WithCachedTypeInfo {
internee: kind,
stable_hash,
flags: flags.flags,
outer_exclusive_binder: flags.outer_exclusive_binder,
};

InternedInSet(
self.arena.alloc(WithStableHash { internee: ty_struct, stable_hash }),
)
}))
})
.0,
))
Expand Down Expand Up @@ -246,16 +246,12 @@ impl<'tcx> CtxtInterners<'tcx> {
let stable_hash =
self.stable_hash(&flags, sess, definitions, cstore, source_span, &kind);

let predicate_struct = PredicateS {
kind,
InternedInSet(self.arena.alloc(WithCachedTypeInfo {
internee: kind,
stable_hash,
flags: flags.flags,
outer_exclusive_binder: flags.outer_exclusive_binder,
};

InternedInSet(
self.arena
.alloc(WithStableHash { internee: predicate_struct, stable_hash }),
)
}))
})
.0,
))
Expand Down Expand Up @@ -2104,7 +2100,7 @@ macro_rules! sty_debug_print {
let shards = tcx.interners.type_.lock_shards();
let types = shards.iter().flat_map(|shard| shard.keys());
for &InternedInSet(t) in types {
let variant = match t.kind {
let variant = match t.internee {
ty::Bool | ty::Char | ty::Int(..) | ty::Uint(..) |
ty::Float(..) | ty::Str | ty::Never => continue,
ty::Error(_) => /* unimportant */ continue,
Expand Down Expand Up @@ -2214,51 +2210,26 @@ impl<'tcx, T: 'tcx + ?Sized> IntoPointer for InternedInSet<'tcx, T> {
}

#[allow(rustc::usage_of_ty_tykind)]
impl<'tcx> Borrow<TyKind<'tcx>> for InternedInSet<'tcx, WithStableHash<TyS<'tcx>>> {
fn borrow<'a>(&'a self) -> &'a TyKind<'tcx> {
&self.0.kind
}
}

impl<'tcx> PartialEq for InternedInSet<'tcx, WithStableHash<TyS<'tcx>>> {
fn eq(&self, other: &InternedInSet<'tcx, WithStableHash<TyS<'tcx>>>) -> bool {
// The `Borrow` trait requires that `x.borrow() == y.borrow()` equals
// `x == y`.
self.0.kind == other.0.kind
}
}

impl<'tcx> Eq for InternedInSet<'tcx, WithStableHash<TyS<'tcx>>> {}

impl<'tcx> Hash for InternedInSet<'tcx, WithStableHash<TyS<'tcx>>> {
fn hash<H: Hasher>(&self, s: &mut H) {
// The `Borrow` trait requires that `x.borrow().hash(s) == x.hash(s)`.
self.0.kind.hash(s)
}
}

impl<'tcx> Borrow<Binder<'tcx, PredicateKind<'tcx>>>
for InternedInSet<'tcx, WithStableHash<PredicateS<'tcx>>>
{
fn borrow<'a>(&'a self) -> &'a Binder<'tcx, PredicateKind<'tcx>> {
&self.0.kind
impl<'tcx, T> Borrow<T> for InternedInSet<'tcx, WithCachedTypeInfo<T>> {
fn borrow<'a>(&'a self) -> &'a T {
&self.0.internee
}
}

impl<'tcx> PartialEq for InternedInSet<'tcx, WithStableHash<PredicateS<'tcx>>> {
fn eq(&self, other: &InternedInSet<'tcx, WithStableHash<PredicateS<'tcx>>>) -> bool {
impl<'tcx, T: PartialEq> PartialEq for InternedInSet<'tcx, WithCachedTypeInfo<T>> {
fn eq(&self, other: &InternedInSet<'tcx, WithCachedTypeInfo<T>>) -> bool {
// The `Borrow` trait requires that `x.borrow() == y.borrow()` equals
// `x == y`.
self.0.kind == other.0.kind
self.0.internee == other.0.internee
}
}

impl<'tcx> Eq for InternedInSet<'tcx, WithStableHash<PredicateS<'tcx>>> {}
impl<'tcx, T: Eq> Eq for InternedInSet<'tcx, WithCachedTypeInfo<T>> {}

impl<'tcx> Hash for InternedInSet<'tcx, WithStableHash<PredicateS<'tcx>>> {
impl<'tcx, T: Hash> Hash for InternedInSet<'tcx, WithCachedTypeInfo<T>> {
fn hash<H: Hasher>(&self, s: &mut H) {
// The `Borrow` trait requires that `x.borrow().hash(s) == x.hash(s)`.
self.0.kind.hash(s)
self.0.internee.hash(s)
}
}

Expand Down
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