diff --git a/src/libraries/System.Linq/src/System/Linq/Range.SpeedOpt.cs b/src/libraries/System.Linq/src/System/Linq/Range.SpeedOpt.cs
index c058142839c673..176d0edc1a076c 100644
--- a/src/libraries/System.Linq/src/System/Linq/Range.SpeedOpt.cs
+++ b/src/libraries/System.Linq/src/System/Linq/Range.SpeedOpt.cs
@@ -45,7 +45,7 @@ private static void Fill(Span<int> destination, int value)
                     Vector<int>.Count <= 8 &&
                     destination.Length >= Vector<int>.Count)
                 {
-                    Vector<int> init = new Vector<int>((ReadOnlySpan<int>)new int[] { 0, 1, 2, 3, 4, 5, 6, 7 });
+                    Vector<int> init = new Vector<int>((ReadOnlySpan<int>)[0, 1, 2, 3, 4, 5, 6, 7]);
                     Vector<int> current = new Vector<int>(value) + init;
                     Vector<int> increment = new Vector<int>(Vector<int>.Count);
 
diff --git a/src/libraries/System.Net.Primitives/src/System/Net/IPAddress.cs b/src/libraries/System.Net.Primitives/src/System/Net/IPAddress.cs
index a4c0dc55200196..bdd381fc04901c 100644
--- a/src/libraries/System.Net.Primitives/src/System/Net/IPAddress.cs
+++ b/src/libraries/System.Net.Primitives/src/System/Net/IPAddress.cs
@@ -21,18 +21,18 @@ namespace System.Net
     /// </devdoc>
     public class IPAddress : ISpanFormattable, ISpanParsable<IPAddress>, IUtf8SpanFormattable
     {
-        public static readonly IPAddress Any = new ReadOnlyIPAddress(new byte[] { 0, 0, 0, 0 });
-        public static readonly IPAddress Loopback = new ReadOnlyIPAddress(new byte[] { 127, 0, 0, 1 });
-        public static readonly IPAddress Broadcast = new ReadOnlyIPAddress(new byte[] { 255, 255, 255, 255 });
+        public static readonly IPAddress Any = new ReadOnlyIPAddress([0, 0, 0, 0]);
+        public static readonly IPAddress Loopback = new ReadOnlyIPAddress([127, 0, 0, 1]);
+        public static readonly IPAddress Broadcast = new ReadOnlyIPAddress([255, 255, 255, 255]);
         public static readonly IPAddress None = Broadcast;
 
         internal const uint LoopbackMaskHostOrder = 0xFF000000;
 
-        public static readonly IPAddress IPv6Any = new IPAddress((ReadOnlySpan<byte>)new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0);
-        public static readonly IPAddress IPv6Loopback = new IPAddress((ReadOnlySpan<byte>)new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }, 0);
+        public static readonly IPAddress IPv6Any = new IPAddress((ReadOnlySpan<byte>)[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], 0);
+        public static readonly IPAddress IPv6Loopback = new IPAddress((ReadOnlySpan<byte>)[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1], 0);
         public static readonly IPAddress IPv6None = IPv6Any;
 
-        private static readonly IPAddress s_loopbackMappedToIPv6 = new IPAddress((ReadOnlySpan<byte>)new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 127, 0, 0, 1 }, 0);
+        private static readonly IPAddress s_loopbackMappedToIPv6 = new IPAddress((ReadOnlySpan<byte>)[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 127, 0, 0, 1], 0);
 
         /// <summary>
         /// For IPv4 addresses, this field stores the Address.
diff --git a/src/libraries/System.Private.CoreLib/src/System/Text/UTF32Encoding.cs b/src/libraries/System.Private.CoreLib/src/System/Text/UTF32Encoding.cs
index 9afbf6736ff08c..83d4e2ee6daa21 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Text/UTF32Encoding.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Text/UTF32Encoding.cs
@@ -1122,8 +1122,8 @@ public override byte[] GetPreamble()
         public override ReadOnlySpan<byte> Preamble =>
             GetType() != typeof(UTF32Encoding) ? new ReadOnlySpan<byte>(GetPreamble()) : // in case a derived UTF32Encoding overrode GetPreamble
             !_emitUTF32ByteOrderMark ? default :
-            _bigEndian ? (ReadOnlySpan<byte>)new byte[4] { 0x00, 0x00, 0xFE, 0xFF } : // uses C# compiler's optimization for static byte[] data
-            (ReadOnlySpan<byte>)new byte[4] { 0xFF, 0xFE, 0x00, 0x00 };
+            _bigEndian ? [0x00, 0x00, 0xFE, 0xFF] :
+            [0xFF, 0xFE, 0x00, 0x00];
 
         public override bool Equals([NotNullWhen(true)] object? value)
         {
diff --git a/src/libraries/System.Private.CoreLib/src/System/Text/UnicodeEncoding.cs b/src/libraries/System.Private.CoreLib/src/System/Text/UnicodeEncoding.cs
index 9cf17f76706d79..6bee6e9d6aae4c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Text/UnicodeEncoding.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Text/UnicodeEncoding.cs
@@ -1746,8 +1746,8 @@ public override byte[] GetPreamble()
         public override ReadOnlySpan<byte> Preamble =>
             GetType() != typeof(UnicodeEncoding) ? new ReadOnlySpan<byte>(GetPreamble()) : // in case a derived UnicodeEncoding overrode GetPreamble
             !byteOrderMark ? default :
-            bigEndian ? (ReadOnlySpan<byte>)new byte[2] { 0xfe, 0xff } : // uses C# compiler's optimization for static byte[] data
-            (ReadOnlySpan<byte>)new byte[2] { 0xff, 0xfe };
+            bigEndian ? [0xfe, 0xff] :
+            [0xff, 0xfe];
 
         public override int GetMaxByteCount(int charCount)
         {