Improve SeqEquals shape (#84524)

dotnet · Apr 17, 2023 · 7dbf6a5 · 7dbf6a5
1 parent e121d77
commit 7dbf6a5
Showing 1 changed file with 9 additions and 6 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.cs b/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.cs
@@ -1426,17 +1426,18 @@ private static void ThrowNullLowHighInclusive<T>(T? lowInclusive, T? highInclusi
         public static unsafe bool SequenceEqual<T>(this Span<T> span, ReadOnlySpan<T> other) where T : IEquatable<T>?
         {
             int length = span.Length;
+            int otherLength = other.Length;
 
             if (RuntimeHelpers.IsBitwiseEquatable<T>())
             {
-                return length == other.Length &&
+                return length == otherLength &&
                 SpanHelpers.SequenceEqual(
                     ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(span)),
                     ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(other)),
-                    ((uint)length) * (nuint)sizeof(T));  // If this multiplication overflows, the Span we got overflows the entire address range. There's no happy outcome for this api in such a case so we choose not to take the overhead of checking.
+                    ((uint)otherLength) * (nuint)sizeof(T));  // If this multiplication overflows, the Span we got overflows the entire address range. There's no happy outcome for this api in such a case so we choose not to take the overhead of checking.
             }
 
-            return length == other.Length && SpanHelpers.SequenceEqual(ref MemoryMarshal.GetReference(span), ref MemoryMarshal.GetReference(other), length);
+            return length == otherLength && SpanHelpers.SequenceEqual(ref MemoryMarshal.GetReference(span), ref MemoryMarshal.GetReference(other), length);
         }
 
         /// <summary>
@@ -2161,16 +2162,18 @@ public static int LastIndexOfAny<T>(this ReadOnlySpan<T> span, IndexOfAnyValues<
         public static unsafe bool SequenceEqual<T>(this ReadOnlySpan<T> span, ReadOnlySpan<T> other) where T : IEquatable<T>?
         {
             int length = span.Length;
+            int otherLength = other.Length;
+
             if (RuntimeHelpers.IsBitwiseEquatable<T>())
             {
-                return length == other.Length &&
+                return length == otherLength &&
                     SpanHelpers.SequenceEqual(
                         ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(span)),
                         ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(other)),
-                        ((uint)length) * (nuint)sizeof(T));  // If this multiplication overflows, the Span we got overflows the entire address range. There's no happy outcome for this API in such a case so we choose not to take the overhead of checking.
+                        ((uint)otherLength) * (nuint)sizeof(T));  // If this multiplication overflows, the Span we got overflows the entire address range. There's no happy outcome for this API in such a case so we choose not to take the overhead of checking.
             }
 
-            return length == other.Length && SpanHelpers.SequenceEqual(ref MemoryMarshal.GetReference(span), ref MemoryMarshal.GetReference(other), length);
+            return length == otherLength && SpanHelpers.SequenceEqual(ref MemoryMarshal.GetReference(span), ref MemoryMarshal.GetReference(other), length);
         }
 
         /// <summary>