CoreFX dotnet#24343 Vector using Span

dotnet/corefx#24343

Author: WinCPP

src/mscorlib/shared/System/Numerics/Vector.cs

@@ -2,9 +2,11 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Internal.Runtime.CompilerServices;
 using System.Globalization;
 using System.Numerics.Hashing;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 
 namespace System.Numerics
@@ -763,6 +765,17 @@ private Vector(ref Register existingRegister)
         {
             this.register = existingRegister;
         }
+
+        /// <summary>
+        /// Constructs a vector from the given span.
+        /// The span must contain at least Vector'T.Count elements.
+        /// </summary>
+        [Intrinsic]
+        public unsafe Vector(Span<T> values)
+            : this()
+        {
+            this = Unsafe.ReadUnaligned<Vector<T>>(ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(values)));
+        }
         #endregion Constructors
 
         #region Public Instance Methods

src/mscorlib/shared/System/Numerics/Vector.tt

@@ -7,9 +7,11 @@
 <#@ import namespace="System.Runtime.InteropServices" #>
 <#@ include file="GenerationConfig.ttinclude" #><# GenerateCopyrightHeader(); #>
 
+using Internal.Runtime.CompilerServices;
 using System.Globalization;
 using System.Numerics.Hashing;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 
 namespace System.Numerics
@@ -283,6 +285,17 @@ namespace System.Numerics
         {
             this.register = existingRegister;
         }
+
+        /// <summary>
+        /// Constructs a vector from the given span.
+        /// The span must contain at least Vector'T.Count elements.
+        /// </summary>
+        [Intrinsic]
+        public unsafe Vector(Span<T> values)
+            : this()
+        {
+            this = Unsafe.ReadUnaligned<Vector<T>>(ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(values)));
+        }
         #endregion Constructors
 
         #region Public Instance Methods