Switch StableHasher from SipHash to HighwayHash

This changes the hash in the legacy symbol mangling format - if this is
undesired, we could use SipHash just for symbol mangling.

Author: Aaron1011

Cargo.lock

@@ -1578,6 +1578,12 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "644f9158b2f133fd50f5fb3242878846d9eb792e445c893805ff0e3824006e35"
 
+[[package]]
+name = "highway"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66920f2e905206a4aca271ae71f1638f10854e3739f162fc465fb8aecce44446"
+
 [[package]]
 name = "home"
 version = "0.5.3"
@@ -3845,6 +3851,7 @@ dependencies = [
  "cfg-if 0.1.10",
  "crossbeam-utils 0.7.2",
  "ena",
+ "highway",
  "indexmap",
  "jobserver",
  "libc",

compiler/rustc_data_structures/Cargo.toml

@@ -29,6 +29,7 @@ measureme = "9.1.0"
 libc = "0.2"
 stacker = "0.1.12"
 tempfile = "3.0.5"
+highway = "0.6.3"
 
 [dependencies.parking_lot]
 version = "0.11"

compiler/rustc_data_structures/src/stable_hasher.rs

@@ -1,4 +1,4 @@
-use crate::sip128::SipHasher128;
+use highway::{HighwayHash, HighwayHasher, Key};
 use rustc_index::bit_set;
 use rustc_index::vec;
 use smallvec::SmallVec;
@@ -16,7 +16,7 @@ mod tests;
 /// hashing and the architecture dependent `isize` and `usize` types are
 /// extended to 64 bits if needed.
 pub struct StableHasher {
-    state: SipHasher128,
+    state: HighwayHasher,
 }
 
 impl ::std::fmt::Debug for StableHasher {
@@ -32,7 +32,7 @@ pub trait StableHasherResult: Sized {
 impl StableHasher {
     #[inline]
     pub fn new() -> Self {
-        StableHasher { state: SipHasher128::new_with_keys(0, 0) }
+        StableHasher { state: HighwayHasher::new(Key([0, 0, 0, 0])) }
     }
 
     #[inline]
@@ -50,14 +50,15 @@ impl StableHasherResult for u128 {
 
 impl StableHasherResult for u64 {
     fn finish(hasher: StableHasher) -> Self {
-        hasher.finalize().0
+        hasher.state.finalize64()
     }
 }
 
 impl StableHasher {
     #[inline]
     pub fn finalize(self) -> (u64, u64) {
-        self.state.finish128()
+        let [first, second] = self.state.finalize128();
+        (first, second)
     }
 }
 
@@ -68,7 +69,7 @@ impl Hasher for StableHasher {
 
     #[inline]
     fn write(&mut self, bytes: &[u8]) {
-        self.state.write(bytes);
+        self.state.append(bytes);
     }
 
     #[inline]

src/tools/tidy/src/deps.rs

@@ -105,6 +105,7 @@ const PERMITTED_DEPENDENCIES: &[&str] = &[
     "gsgdt",
     "hashbrown",
     "hermit-abi",
+    "highway",
     "humantime",
     "indexmap",
     "instant",