let F14HashToken equality-comparison skip the tag element

Summary: It only needs to compare the hash element and can skip comparing the derived tag element. The derived tag element is indended as a precomputed word to accelerate lookup but only decelerates equality-comparison. Reviewed By: DenisYaroshevskiy Differential Revision: D60044472 fbshipit-source-id: 7b18667b993b817b1ce3c78667693f5f12fb48e5
facebook · Jul 22, 2024 · dc5586d · dc5586d
1 parent 404b94b
commit dc5586d
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/folly/container/detail/F14Table.h b/folly/container/detail/F14Table.h
@@ -214,11 +214,11 @@ class F14HashToken final {
 
   friend constexpr bool operator==(
       F14HashToken const& a, F14HashToken const& b) noexcept {
-    return a.hp_ == b.hp_;
+    return a.hp_.first == b.hp_.first; // processed hash but not tag
   }
   friend constexpr bool operator!=(
       F14HashToken const& a, F14HashToken const& b) noexcept {
-    return a.hp_ != b.hp_;
+    return !(a == b);
   }
 
  private: