Rollup merge of rust-lang#137095 - saethlin:use-hash64-for-hashes, r=…

…workingjubilee Replace some u64 hashes with Hash64 I introduced the Hash64 and Hash128 types in rust-lang#110083, essentially as a mechanism to prevent hashes from landing in our leb128 encoding paths. If you just have a u64 or u128 field in a struct then derive Encodable/Decodable, that number gets leb128 encoding. So if you need to store a hash or some other value which behaves very close to a hash, don't store it as a u64. This reverts part of rust-lang#117603, which turned an encoded Hash64 into a u64. Based on rust-lang#110083, I don't expect this to be perf-sensitive on its own, though I expect that it may help stabilize some of the small rmeta size fluctuations we currently see in perf reports.
workingjubilee · Feb 16, 2025 · 4ea69ec · 4ea69ec
2 parents b044822 + 4cf2186
commit 4ea69ec
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Showing 51 changed files with 173 additions and 78 deletions.
diff --git a/Cargo.lock b/Cargo.lock
@@ -3317,6 +3317,7 @@ dependencies = [
  "rand 0.8.5",
  "rand_xoshiro",
  "rustc_data_structures",
+ "rustc_hashes",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",
@@ -3544,6 +3545,7 @@ dependencies = [
  "rustc_errors",
  "rustc_fluent_macro",
  "rustc_fs_util",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_index",
  "rustc_llvm",
@@ -3586,6 +3588,7 @@ dependencies = [
  "rustc_errors",
  "rustc_fluent_macro",
  "rustc_fs_util",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_hir_pretty",
  "rustc_incremental",
@@ -3658,6 +3661,7 @@ dependencies = [
  "rustc-stable-hash",
  "rustc_arena",
  "rustc_graphviz",
+ "rustc_hashes",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",
@@ -3768,6 +3772,7 @@ dependencies = [
  "rustc_error_codes",
  "rustc_error_messages",
  "rustc_fluent_macro",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_index",
  "rustc_lexer",
@@ -3840,6 +3845,13 @@ version = "0.0.0"
 name = "rustc_graphviz"
 version = "0.0.0"
 
+[[package]]
+name = "rustc_hashes"
+version = "0.0.0"
+dependencies = [
+ "rustc-stable-hash",
+]
+
 [[package]]
 name = "rustc_hir"
 version = "0.0.0"
@@ -3849,6 +3861,7 @@ dependencies = [
  "rustc_arena",
  "rustc_ast",
  "rustc_data_structures",
+ "rustc_hashes",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",
@@ -4169,6 +4182,7 @@ dependencies = [
  "rustc_feature",
  "rustc_fluent_macro",
  "rustc_graphviz",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_hir_pretty",
  "rustc_index",
@@ -4405,6 +4419,7 @@ dependencies = [
  "measureme",
  "rustc_data_structures",
  "rustc_errors",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_index",
  "rustc_middle",
@@ -4428,6 +4443,7 @@ dependencies = [
  "rustc_errors",
  "rustc_feature",
  "rustc_fluent_macro",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_index",
  "rustc_macros",
@@ -4488,6 +4504,7 @@ name = "rustc_serialize"
 version = "0.0.0"
 dependencies = [
  "indexmap",
+ "rustc_hashes",
  "rustc_macros",
  "smallvec",
  "tempfile",
@@ -4508,6 +4525,7 @@ dependencies = [
  "rustc_feature",
  "rustc_fluent_macro",
  "rustc_fs_util",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_lint_defs",
  "rustc_macros",
@@ -4549,6 +4567,7 @@ dependencies = [
  "md-5",
  "rustc_arena",
  "rustc_data_structures",
+ "rustc_hashes",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",
@@ -4568,6 +4587,7 @@ dependencies = [
  "rustc_abi",
  "rustc_data_structures",
  "rustc_errors",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_middle",
  "rustc_session",
@@ -4663,6 +4683,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_errors",
  "rustc_fluent_macro",
+ "rustc_hashes",
  "rustc_hir",
  "rustc_index",
  "rustc_infer",

diff --git 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
@@ -2,6 +2,7 @@ use std::fmt::{self, Write};
 use std::ops::{Bound, Deref};
 use std::{cmp, iter};
 
+use rustc_hashes::Hash64;
 use rustc_index::Idx;
 use tracing::debug;
 
@@ -133,7 +134,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
             size,
             max_repr_align: None,
             unadjusted_abi_align: align.abi,
-            randomization_seed: combined_seed,
+            randomization_seed: Hash64::new(combined_seed),
         }
     }
 
@@ -226,7 +227,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
             size: Size::ZERO,
             max_repr_align: None,
             unadjusted_abi_align: dl.i8_align.abi,
-            randomization_seed: 0,
+            randomization_seed: Hash64::ZERO,
         }
     }
 
@@ -1058,7 +1059,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
         // unsizable tail fields are excluded so that we use the same seed for the sized and unsized layouts.
         let field_seed = fields_excluding_tail
             .iter()
-            .fold(0u64, |acc, f| acc.wrapping_add(f.randomization_seed));
+            .fold(Hash64::ZERO, |acc, f| acc.wrapping_add(f.randomization_seed));
 
         if optimize_field_order && fields.len() > 1 {
             // If `-Z randomize-layout` was enabled for the type definition we can shuffle
@@ -1072,7 +1073,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
                     // `ReprOptions.field_shuffle_seed` is a deterministic seed we can use to randomize field
                     // ordering.
                     let mut rng = rand_xoshiro::Xoshiro128StarStar::seed_from_u64(
-                        field_seed.wrapping_add(repr.field_shuffle_seed),
+                        field_seed.wrapping_add(repr.field_shuffle_seed).as_u64(),
                     );
 
                     // Shuffle the ordering of the fields.

diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
@@ -50,6 +50,7 @@ use std::str::FromStr;
 use bitflags::bitflags;
 #[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};
@@ -140,7 +141,7 @@ pub struct ReprOptions {
     /// hash without loss, but it does pay the price of being larger.
     /// Everything's a tradeoff, a 64-bit seed should be sufficient for our
     /// purposes (primarily `-Z randomize-layout`)
-    pub field_shuffle_seed: u64,
+    pub field_shuffle_seed: Hash64,
 }
 
 impl ReprOptions {
@@ -1727,7 +1728,7 @@ pub struct LayoutData<FieldIdx: Idx, VariantIdx: Idx> {
     /// transmuted to `Foo<U>` we aim to create probalistically distinct seeds so that Foo can choose
     /// to reorder its fields based on that information. The current implementation is a conservative
     /// approximation of this goal.
-    pub randomization_seed: u64,
+    pub randomization_seed: Hash64,
 }
 
 impl<FieldIdx: Idx, VariantIdx: Idx> LayoutData<FieldIdx, VariantIdx> {
@@ -1781,7 +1782,7 @@ impl<FieldIdx: Idx, VariantIdx: Idx> LayoutData<FieldIdx, VariantIdx> {
             align,
             max_repr_align: None,
             unadjusted_abi_align: align.abi,
-            randomization_seed,
+            randomization_seed: Hash64::new(randomization_seed),
         }
     }
 }

diff --git 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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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