2 files changed, 9 insertions, 7 deletions
diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs
index b8773f9ff38..9e33824afe2 100644
--- 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_data_structures::stable_hasher::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
index da1c706d67c..d3847e5f272 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -48,6 +48,7 @@ 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_index::{Idx, IndexSlice, IndexVec};
@@ -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),
         }
     }
 }