Move hashes from rustc_data_structure to rustc_hashes so they can be shared with rust-analyzer

43 files changed, 102 insertions, 62 deletions

diff --git a/compiler/rustc_abi/Cargo.toml b/compiler/rustc_abi/Cargo.toml
index 1013f1d3958..3d6f4a6a109 100644
--- a/compiler/rustc_abi/Cargo.toml
+++ b/compiler/rustc_abi/Cargo.toml
@@ -9,6 +9,7 @@ bitflags = "2.4.1"
 rand = { version = "0.8.4", default-features = false, optional = true }
 rand_xoshiro = { version = "0.6.0", optional = true }
 rustc_data_structures = { path = "../rustc_data_structures", optional = true  }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index", default-features = false }
 rustc_macros = { path = "../rustc_macros", optional = true }
 rustc_serialize = { path = "../rustc_serialize", optional = true  }
diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs
index 9e33824afe2..45cd0b517f6 100644
--- a/compiler/rustc_abi/src/layout.rs
+++ b/compiler/rustc_abi/src/layout.rs
@@ -2,7 +2,7 @@ use std::fmt::{self, Write};
 use std::ops::{Bound, Deref};
 use std::{cmp, iter};
 
-use rustc_data_structures::stable_hasher::Hash64;
+use rustc_hashes::Hash64;
 use rustc_index::Idx;
 use tracing::debug;
 
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index d3847e5f272..dbb4bed5cdd 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -48,9 +48,9 @@ use std::ops::{Add, AddAssign, Mul, RangeInclusive, Sub};
 use std::str::FromStr;
 
 use bitflags::bitflags;
-use rustc_data_structures::stable_hasher::Hash64;
 #[cfg(feature = "nightly")]
 use rustc_data_structures::stable_hasher::StableOrd;
+use rustc_hashes::Hash64;
 use rustc_index::{Idx, IndexSlice, IndexVec};
 #[cfg(feature = "nightly")]
 use rustc_macros::{Decodable_Generic, Encodable_Generic, HashStable_Generic};
diff --git a/compiler/rustc_codegen_llvm/Cargo.toml b/compiler/rustc_codegen_llvm/Cargo.toml
index 94f21ac5f57..a8172270548 100644
--- a/compiler/rustc_codegen_llvm/Cargo.toml
+++ b/compiler/rustc_codegen_llvm/Cargo.toml
@@ -25,6 +25,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_fs_util = { path = "../rustc_fs_util" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_llvm = { path = "../rustc_llvm" }
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
index 78b3a7f8541..f17d98fa242 100644
--- a/compiler/rustc_codegen_llvm/src/common.rs
+++ b/compiler/rustc_codegen_llvm/src/common.rs
@@ -7,7 +7,8 @@ use rustc_abi::{AddressSpace, HasDataLayout};
 use rustc_ast::Mutability;
 use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::traits::*;
-use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash128;
 use rustc_hir::def_id::DefId;
 use rustc_middle::bug;
 use rustc_middle::mir::interpret::{ConstAllocation, GlobalAlloc, Scalar};
diff --git a/compiler/rustc_codegen_ssa/Cargo.toml b/compiler/rustc_codegen_ssa/Cargo.toml
index 2afc1efc1b3..963d9258be6 100644
--- a/compiler/rustc_codegen_ssa/Cargo.toml
+++ b/compiler/rustc_codegen_ssa/Cargo.toml
@@ -25,6 +25,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_fs_util = { path = "../rustc_fs_util" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_incremental = { path = "../rustc_incremental" }
diff --git a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
index 53953b089c6..84703a0a156 100644
--- a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
+++ b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
@@ -15,7 +15,8 @@ use std::fmt::Write;
 
 use rustc_abi::Integer;
 use rustc_data_structures::fx::FxHashSet;
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash64;
 use rustc_hir::def_id::DefId;
 use rustc_hir::definitions::{DefPathData, DefPathDataName, DisambiguatedDefPathData};
 use rustc_hir::{CoroutineDesugaring, CoroutineKind, CoroutineSource, Mutability};
diff --git a/compiler/rustc_data_structures/Cargo.toml b/compiler/rustc_data_structures/Cargo.toml
index a8f83ca13e2..1705af1e210 100644
--- a/compiler/rustc_data_structures/Cargo.toml
+++ b/compiler/rustc_data_structures/Cargo.toml
@@ -18,6 +18,7 @@ rustc-rayon = { version = "0.5.1", features = ["indexmap"] }
 rustc-stable-hash = { version = "0.1.0", features = ["nightly"] }
 rustc_arena = { path = "../rustc_arena" }
 rustc_graphviz = { path = "../rustc_graphviz" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index", package = "rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_data_structures/src/fingerprint.rs b/compiler/rustc_data_structures/src/fingerprint.rs
index 16c66824c5b..c7c0d0ab072 100644
--- a/compiler/rustc_data_structures/src/fingerprint.rs
+++ b/compiler/rustc_data_structures/src/fingerprint.rs
@@ -1,10 +1,9 @@
 use std::hash::{Hash, Hasher};
 
+use rustc_hashes::Hash64;
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 
-use crate::stable_hasher::{
-    FromStableHash, Hash64, StableHasherHash, impl_stable_traits_for_trivial_type,
-};
+use crate::stable_hasher::{FromStableHash, StableHasherHash, impl_stable_traits_for_trivial_type};
 
 #[cfg(test)]
 mod tests;
diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index 6ef73debadd..66d3834d857 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -84,7 +84,6 @@ pub mod vec_cache;
 pub mod work_queue;
 
 mod atomic_ref;
-mod hashes;
 
 /// This calls the passed function while ensuring it won't be inlined into the caller.
 #[inline(never)]
diff --git a/compiler/rustc_data_structures/src/stable_hasher.rs b/compiler/rustc_data_structures/src/stable_hasher.rs
index 9cd0cc499ca..ffbe54d6206 100644
--- a/compiler/rustc_data_structures/src/stable_hasher.rs
+++ b/compiler/rustc_data_structures/src/stable_hasher.rs
@@ -10,12 +10,11 @@ use smallvec::SmallVec;
 #[cfg(test)]
 mod tests;
 
+use rustc_hashes::{Hash64, Hash128};
 pub use rustc_stable_hash::{
     FromStableHash, SipHasher128Hash as StableHasherHash, StableSipHasher128 as StableHasher,
 };
 
-pub use crate::hashes::{Hash64, Hash128};
-
 /// Something that implements `HashStable<CTX>` can be hashed in a way that is
 /// stable across multiple compilation sessions.
 ///
diff --git a/compiler/rustc_data_structures/src/tagged_ptr/tests.rs b/compiler/rustc_data_structures/src/tagged_ptr/tests.rs
index b1bdee18d6d..9c1e4cefa69 100644
--- a/compiler/rustc_data_structures/src/tagged_ptr/tests.rs
+++ b/compiler/rustc_data_structures/src/tagged_ptr/tests.rs
@@ -1,7 +1,8 @@
 use std::ptr;
 
+use rustc_hashes::Hash128;
+
 use super::*;
-use crate::hashes::Hash128;
 use crate::stable_hasher::{HashStable, StableHasher};
 
 /// A tag type used in [`TaggedRef`] tests.
diff --git a/compiler/rustc_errors/Cargo.toml b/compiler/rustc_errors/Cargo.toml
index fbb6a1cc475..434f8c1c767 100644
--- a/compiler/rustc_errors/Cargo.toml
+++ b/compiler/rustc_errors/Cargo.toml
@@ -14,6 +14,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_error_codes = { path = "../rustc_error_codes" }
 rustc_error_messages = { path = "../rustc_error_messages" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_lexer = { path = "../rustc_lexer" }
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 8ff5dc12596..6fce1fade26 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -58,12 +58,13 @@ pub use emitter::ColorConfig;
 use emitter::{DynEmitter, Emitter, is_case_difference, is_different};
 use rustc_data_structures::AtomicRef;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
-use rustc_data_structures::stable_hasher::{Hash128, StableHasher};
+use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::{DynSend, Lock};
 pub use rustc_error_messages::{
     DiagMessage, FluentBundle, LanguageIdentifier, LazyFallbackBundle, MultiSpan, SpanLabel,
     SubdiagMessage, fallback_fluent_bundle, fluent_bundle,
 };
+use rustc_hashes::Hash128;
 use rustc_lint_defs::LintExpectationId;
 pub use rustc_lint_defs::{Applicability, listify, pluralize};
 use rustc_macros::{Decodable, Encodable};
diff --git a/compiler/rustc_hashes/Cargo.toml b/compiler/rustc_hashes/Cargo.toml
new file mode 100644
index 00000000000..c2bae2fe8cb
--- /dev/null
+++ b/compiler/rustc_hashes/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "rustc_hashes"
+version = "0.0.0"
+edition = "2021"
+
+[dependencies]
+# tidy-alphabetical-start
+rustc-stable-hash = { version = "0.1.0" }
+# tidy-alphabetical-end
diff --git a/compiler/rustc_data_structures/src/hashes.rs b/compiler/rustc_hashes/src/lib.rs
index b25758048bd..3755caaaa29 100644
--- a/compiler/rustc_data_structures/src/hashes.rs
+++ b/compiler/rustc_hashes/src/lib.rs
@@ -1,6 +1,8 @@
 //! rustc encodes a lot of hashes. If hashes are stored as `u64` or `u128`, a `derive(Encodable)`
 //! will apply varint encoding to the hashes, which is less efficient than directly encoding the 8
-//! or 16 bytes of the hash.
+//! or 16 bytes of the hash. And if that hash depends on the `StableCrateHash` (which most in rustc
+//! do), the varint encoding will make the number of bytes encoded fluctuate between compiler
+//! versions.
 //!
 //! The types in this module represent 64-bit or 128-bit hashes produced by a `StableHasher`.
 //! `Hash64` and `Hash128` expose some utility functions to encourage users to not extract the inner
@@ -14,10 +16,9 @@
 use std::fmt;
 use std::ops::BitXorAssign;
 
-use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
-
-use crate::stable_hasher::{FromStableHash, StableHasherHash};
+use rustc_stable_hash::{FromStableHash, SipHasher128Hash as StableHasherHash};
 
+/// A `u64` but encoded with a fixed size; for hashes this encoding is more compact than `u64`.
 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Default)]
 pub struct Hash64 {
     inner: u64,
@@ -49,20 +50,6 @@ impl BitXorAssign<u64> for Hash64 {
     }
 }
 
-impl<S: Encoder> Encodable<S> for Hash64 {
-    #[inline]
-    fn encode(&self, s: &mut S) {
-        s.emit_raw_bytes(&self.inner.to_le_bytes());
-    }
-}
-
-impl<D: Decoder> Decodable<D> for Hash64 {
-    #[inline]
-    fn decode(d: &mut D) -> Self {
-        Self { inner: u64::from_le_bytes(d.read_raw_bytes(8).try_into().unwrap()) }
-    }
-}
-
 impl FromStableHash for Hash64 {
     type Hash = StableHasherHash;
 
@@ -84,6 +71,7 @@ impl fmt::LowerHex for Hash64 {
     }
 }
 
+/// A `u128` but encoded with a fixed size; for hashes this encoding is more compact than `u128`.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Default)]
 pub struct Hash128 {
     inner: u128,
@@ -101,6 +89,11 @@ impl std::hash::Hash for Hash128 {
 
 impl Hash128 {
     #[inline]
+    pub fn new(n: u128) -> Self {
+        Self { inner: n }
+    }
+
+    #[inline]
     pub fn truncate(self) -> Hash64 {
         Hash64 { inner: self.inner as u64 }
     }
@@ -116,20 +109,6 @@ impl Hash128 {
     }
 }
 
-impl<S: Encoder> Encodable<S> for Hash128 {
-    #[inline]
-    fn encode(&self, s: &mut S) {
-        s.emit_raw_bytes(&self.inner.to_le_bytes());
-    }
-}
-
-impl<D: Decoder> Decodable<D> for Hash128 {
-    #[inline]
-    fn decode(d: &mut D) -> Self {
-        Self { inner: u128::from_le_bytes(d.read_raw_bytes(16).try_into().unwrap()) }
-    }
-}
-
 impl FromStableHash for Hash128 {
     type Hash = StableHasherHash;
 
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 5bfc4756ec6..b1516e53173 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -10,6 +10,7 @@ rustc_abi = { path = "../rustc_abi" }
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_hir/src/def_path_hash_map.rs b/compiler/rustc_hir/src/def_path_hash_map.rs
index 9a6dee1e511..35c6e57b877 100644
--- a/compiler/rustc_hir/src/def_path_hash_map.rs
+++ b/compiler/rustc_hir/src/def_path_hash_map.rs
@@ -1,4 +1,4 @@
-use rustc_data_structures::stable_hasher::Hash64;
+use rustc_hashes::Hash64;
 use rustc_span::def_id::DefIndex;
 
 #[derive(Clone, Default)]
diff --git a/compiler/rustc_hir/src/definitions.rs b/compiler/rustc_hir/src/definitions.rs
index dc527240f74..08a0a5225e7 100644
--- a/compiler/rustc_hir/src/definitions.rs
+++ b/compiler/rustc_hir/src/definitions.rs
@@ -7,8 +7,9 @@
 use std::fmt::{self, Write};
 use std::hash::Hash;
 
-use rustc_data_structures::stable_hasher::{Hash64, StableHasher};
+use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::unord::UnordMap;
+use rustc_hashes::Hash64;
 use rustc_index::IndexVec;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::{Symbol, kw, sym};
diff --git a/compiler/rustc_hir/src/tests.rs b/compiler/rustc_hir/src/tests.rs
index e0e63d183c6..0837444ffdb 100644
--- a/compiler/rustc_hir/src/tests.rs
+++ b/compiler/rustc_hir/src/tests.rs
@@ -1,6 +1,6 @@
 #![allow(rustc::symbol_intern_string_literal)]
 
-use rustc_data_structures::stable_hasher::Hash64;
+use rustc_hashes::Hash64;
 use rustc_span::def_id::{DefPathHash, StableCrateId};
 use rustc_span::edition::Edition;
 use rustc_span::{Symbol, create_session_globals_then};
diff --git a/compiler/rustc_middle/Cargo.toml b/compiler/rustc_middle/Cargo.toml
index de722e62043..1b6a174c093 100644
--- a/compiler/rustc_middle/Cargo.toml
+++ b/compiler/rustc_middle/Cargo.toml
@@ -22,6 +22,7 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_graphviz = { path = "../rustc_graphviz" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_index = { path = "../rustc_index" }
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index d4a9aac3733..4a21b6ad237 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -6,8 +6,9 @@ use rustc_attr_parsing::InlineAttr;
 use rustc_data_structures::base_n::{BaseNString, CASE_INSENSITIVE, ToBaseN};
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxIndexMap;
-use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher, ToStableHashKey};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
 use rustc_data_structures::unord::UnordMap;
+use rustc_hashes::Hash128;
 use rustc_hir::ItemId;
 use rustc_hir::def_id::{CrateNum, DefId, DefIdSet, LOCAL_CRATE};
 use rustc_index::Idx;
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 2e90e5251e2..bbb8a9fa671 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -7,11 +7,11 @@ use rustc_abi::{
     PointeeInfo, PointerKind, Primitive, ReprOptions, Scalar, Size, TagEncoding, TargetDataLayout,
     TyAbiInterface, VariantIdx, Variants,
 };
-use rustc_data_structures::stable_hasher::Hash64;
 use rustc_error_messages::DiagMessage;
 use rustc_errors::{
     Diag, DiagArgValue, DiagCtxtHandle, Diagnostic, EmissionGuarantee, IntoDiagArg, Level,
 };
+use rustc_hashes::Hash64;
 use rustc_hir::LangItem;
 use rustc_hir::def_id::DefId;
 use rustc_index::IndexVec;
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 94bd359f6eb..88d57498542 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -5,9 +5,10 @@ use std::{fmt, iter};
 use rustc_abi::{ExternAbi, Float, Integer, IntegerType, Size};
 use rustc_apfloat::Float as _;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::ErrorGuaranteed;
+use rustc_hashes::Hash128;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId};
diff --git a/compiler/rustc_query_impl/Cargo.toml b/compiler/rustc_query_impl/Cargo.toml
index 8b0cc9d726b..fd1d21b6a89 100644
--- a/compiler/rustc_query_impl/Cargo.toml
+++ b/compiler/rustc_query_impl/Cargo.toml
@@ -8,6 +8,7 @@ edition = "2021"
 measureme = "11"
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
diff --git a/compiler/rustc_query_impl/src/plumbing.rs b/compiler/rustc_query_impl/src/plumbing.rs
index e95c186f6b6..f98d6421307 100644
--- a/compiler/rustc_query_impl/src/plumbing.rs
+++ b/compiler/rustc_query_impl/src/plumbing.rs
@@ -4,10 +4,11 @@
 
 use std::num::NonZero;
 
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lock;
 use rustc_data_structures::unord::UnordMap;
 use rustc_errors::DiagInner;
+use rustc_hashes::Hash64;
 use rustc_index::Idx;
 use rustc_middle::bug;
 use rustc_middle::dep_graph::{
diff --git a/compiler/rustc_query_system/Cargo.toml b/compiler/rustc_query_system/Cargo.toml
index a42329b4614..d9560f3eb0f 100644
--- a/compiler/rustc_query_system/Cargo.toml
+++ b/compiler/rustc_query_system/Cargo.toml
@@ -13,6 +13,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
diff --git a/compiler/rustc_query_system/src/query/mod.rs b/compiler/rustc_query_system/src/query/mod.rs
index 82c51193a19..7490a3f3503 100644
--- a/compiler/rustc_query_system/src/query/mod.rs
+++ b/compiler/rustc_query_system/src/query/mod.rs
@@ -11,9 +11,9 @@ mod caches;
 pub use self::caches::{DefIdCache, DefaultCache, QueryCache, SingleCache, VecCache};
 
 mod config;
-use rustc_data_structures::stable_hasher::Hash64;
 use rustc_data_structures::sync::Lock;
 use rustc_errors::DiagInner;
+use rustc_hashes::Hash64;
 use rustc_hir::def::DefKind;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::Span;
diff --git a/compiler/rustc_serialize/Cargo.toml b/compiler/rustc_serialize/Cargo.toml
index 8bf98c16361..a6815c7a447 100644
--- a/compiler/rustc_serialize/Cargo.toml
+++ b/compiler/rustc_serialize/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 indexmap = "2.0.0"
+rustc_hashes = { path = "../rustc_hashes" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 # tidy-alphabetical-end
diff --git a/compiler/rustc_serialize/src/serialize.rs b/compiler/rustc_serialize/src/serialize.rs
index db8555edd0f..1eefd76f92b 100644
--- a/compiler/rustc_serialize/src/serialize.rs
+++ b/compiler/rustc_serialize/src/serialize.rs
@@ -10,6 +10,7 @@ use std::path;
 use std::rc::Rc;
 use std::sync::Arc;
 
+use rustc_hashes::{Hash64, Hash128};
 use smallvec::{Array, SmallVec};
 use thin_vec::ThinVec;
 
@@ -716,3 +717,31 @@ impl<D: Decoder, T: Decodable<D>> Decodable<D> for Arc<[T]> {
         vec.into()
     }
 }
+
+impl<S: Encoder> Encodable<S> for Hash64 {
+    #[inline]
+    fn encode(&self, s: &mut S) {
+        s.emit_raw_bytes(&self.as_u64().to_le_bytes());
+    }
+}
+
+impl<S: Encoder> Encodable<S> for Hash128 {
+    #[inline]
+    fn encode(&self, s: &mut S) {
+        s.emit_raw_bytes(&self.as_u128().to_le_bytes());
+    }
+}
+
+impl<D: Decoder> Decodable<D> for Hash64 {
+    #[inline]
+    fn decode(d: &mut D) -> Self {
+        Self::new(u64::from_le_bytes(d.read_raw_bytes(8).try_into().unwrap()))
+    }
+}
+
+impl<D: Decoder> Decodable<D> for Hash128 {
+    #[inline]
+    fn decode(d: &mut D) -> Self {
+        Self::new(u128::from_le_bytes(d.read_raw_bytes(16).try_into().unwrap()))
+    }
+}
diff --git a/compiler/rustc_session/Cargo.toml b/compiler/rustc_session/Cargo.toml
index b9c535df4bd..31892c13438 100644
--- a/compiler/rustc_session/Cargo.toml
+++ b/compiler/rustc_session/Cargo.toml
@@ -14,6 +14,7 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_fs_util = { path = "../rustc_fs_util" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_lint_defs = { path = "../rustc_lint_defs" }
 rustc_macros = { path = "../rustc_macros" }
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 7d473b86ff5..85ef69ea2b7 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -2934,9 +2934,9 @@ pub(crate) mod dep_tracking {
 
     use rustc_abi::Align;
     use rustc_data_structures::fx::FxIndexMap;
-    use rustc_data_structures::stable_hasher::Hash64;
     use rustc_errors::LanguageIdentifier;
     use rustc_feature::UnstableFeatures;
+    use rustc_hashes::Hash64;
     use rustc_span::RealFileName;
     use rustc_span::edition::Edition;
     use rustc_target::spec::{
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 35819f896c5..351dad3f3e4 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -7,9 +7,9 @@ use std::str;
 use rustc_abi::Align;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::profiling::TimePassesFormat;
-use rustc_data_structures::stable_hasher::Hash64;
 use rustc_errors::{ColorConfig, LanguageIdentifier, TerminalUrl};
 use rustc_feature::UnstableFeatures;
+use rustc_hashes::Hash64;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::edition::Edition;
 use rustc_span::{RealFileName, SourceFileHashAlgorithm};
diff --git a/compiler/rustc_span/Cargo.toml b/compiler/rustc_span/Cargo.toml
index 781fe6a11fe..991c75cc98d 100644
--- a/compiler/rustc_span/Cargo.toml
+++ b/compiler/rustc_span/Cargo.toml
@@ -12,6 +12,7 @@ itoa = "1.0"
 md5 = { package = "md-5", version = "0.10.0" }
 rustc_arena = { path = "../rustc_arena" }
 rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_span/src/def_id.rs b/compiler/rustc_span/src/def_id.rs
index f61ce37131e..641bac88ad0 100644
--- a/compiler/rustc_span/src/def_id.rs
+++ b/compiler/rustc_span/src/def_id.rs
@@ -3,10 +3,9 @@ use std::hash::{BuildHasherDefault, Hash, Hasher};
 
 use rustc_data_structures::AtomicRef;
 use rustc_data_structures::fingerprint::Fingerprint;
-use rustc_data_structures::stable_hasher::{
-    Hash64, HashStable, StableHasher, StableOrd, ToStableHashKey,
-};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableOrd, ToStableHashKey};
 use rustc_data_structures::unhash::Unhasher;
+use rustc_hashes::Hash64;
 use rustc_index::Idx;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_serialize::{Decodable, Encodable};
diff --git a/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs
index 2910bcdf51d..9bf1d305e54 100644
--- a/compiler/rustc_span/src/hygiene.rs
+++ b/compiler/rustc_span/src/hygiene.rs
@@ -33,9 +33,10 @@ use std::sync::Arc;
 
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, HashingControls, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, HashingControls, StableHasher};
 use rustc_data_structures::sync::{Lock, WorkerLocal};
 use rustc_data_structures::unhash::UnhashMap;
+use rustc_hashes::Hash64;
 use rustc_index::IndexVec;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index 0e146baef37..695edc956cd 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -87,9 +87,10 @@ use std::sync::Arc;
 use std::{fmt, iter};
 
 use md5::{Digest, Md5};
-use rustc_data_structures::stable_hasher::{Hash64, Hash128, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::{FreezeLock, FreezeWriteGuard, Lock};
 use rustc_data_structures::unord::UnordMap;
+use rustc_hashes::{Hash64, Hash128};
 use sha1::Sha1;
 use sha2::Sha256;
 
diff --git a/compiler/rustc_symbol_mangling/Cargo.toml b/compiler/rustc_symbol_mangling/Cargo.toml
index 1fb647cab5b..4c51c908f54 100644
--- a/compiler/rustc_symbol_mangling/Cargo.toml
+++ b/compiler/rustc_symbol_mangling/Cargo.toml
@@ -11,6 +11,7 @@ rustc-demangle = "0.1.21"
 rustc_abi = { path = "../rustc_abi" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_session = { path = "../rustc_session" }
diff --git a/compiler/rustc_symbol_mangling/src/hashed.rs b/compiler/rustc_symbol_mangling/src/hashed.rs
index 07c5f544792..e965e6a7d53 100644
--- a/compiler/rustc_symbol_mangling/src/hashed.rs
+++ b/compiler/rustc_symbol_mangling/src/hashed.rs
@@ -1,6 +1,7 @@
 use std::fmt::Write;
 
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash64;
 use rustc_hir::def_id::CrateNum;
 use rustc_middle::ty::{Instance, TyCtxt};
 
diff --git a/compiler/rustc_symbol_mangling/src/legacy.rs b/compiler/rustc_symbol_mangling/src/legacy.rs
index 8ae35572d01..88754f1f15b 100644
--- a/compiler/rustc_symbol_mangling/src/legacy.rs
+++ b/compiler/rustc_symbol_mangling/src/legacy.rs
@@ -1,7 +1,8 @@
 use std::fmt::{self, Write};
 use std::mem::{self, discriminant};
 
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash64;
 use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
 use rustc_middle::bug;
diff --git a/compiler/rustc_ty_utils/Cargo.toml b/compiler/rustc_ty_utils/Cargo.toml
index 40356e0c978..f88f8c38d50 100644
--- a/compiler/rustc_ty_utils/Cargo.toml
+++ b/compiler/rustc_ty_utils/Cargo.toml
@@ -11,6 +11,7 @@ rustc_ast_ir = { path = "../rustc_ast_ir" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_infer = { path = "../rustc_infer" }
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index 6a67009fe90..8429e68b600 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -9,7 +9,7 @@ use rustc_abi::{
     HasDataLayout, Layout, LayoutCalculatorError, LayoutData, Niche, ReprOptions, Scalar, Size,
     StructKind, TagEncoding, VariantIdx, Variants, WrappingRange,
 };
-use rustc_data_structures::stable_hasher::Hash64;
+use rustc_hashes::Hash64;
 use rustc_index::bit_set::DenseBitSet;
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::bug;
diff --git a/compiler/rustc_type_ir/src/ty_kind.rs b/compiler/rustc_type_ir/src/ty_kind.rs
index 52e4fa19cb0..83631f7fe34 100644
--- a/compiler/rustc_type_ir/src/ty_kind.rs
+++ b/compiler/rustc_type_ir/src/ty_kind.rs
@@ -14,6 +14,7 @@ use rustc_type_ir_macros::{Lift_Generic, TypeFoldable_Generic, TypeVisitable_Gen
 use self::TyKind::*;
 pub use self::closure::*;
 use crate::inherent::*;
+#[cfg(feature = "nightly")]
 use crate::visit::TypeVisitable;
 use crate::{self as ty, DebruijnIndex, Interner};