Write 2 values once

dotnet · Jul 3, 2024 · 8f42dae · 8f42dae
1 parent 23b8c61
commit 8f42dae
Showing 1 changed file with 27 additions and 4 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Base64Url/Base64UrlEncoder.cs b/src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Base64Url/Base64UrlEncoder.cs
@@ -254,6 +254,19 @@ public unsafe void EncodeOneOptionallyPadTwo(byte* oneByte, byte* dest, ref byte
                 byte i0 = Unsafe.Add(ref encodingMap, (IntPtr)(i >> 10));
                 byte i1 = Unsafe.Add(ref encodingMap, (IntPtr)((i >> 4) & 0x3F));
 
+                ushort result;
+
+                if (BitConverter.IsLittleEndian)
+                {
+                    result = (ushort)(i0 | (i1 << 8));
+                }
+                else
+                {
+                    result = (ushort)((i0 << 8) | i1);
+                }
+
+                Unsafe.WriteUnaligned(dest, result);
+
                 dest[0] = i0;
                 dest[1] = i1;
             }
@@ -331,11 +344,21 @@ public unsafe void EncodeOneOptionallyPadTwo(byte* oneByte, ushort* dest, ref by
 
                 uint i = t0 << 8;
 
-                ushort i0 = Unsafe.Add(ref encodingMap, (IntPtr)(i >> 10));
-                ushort i1 = Unsafe.Add(ref encodingMap, (IntPtr)((i >> 4) & 0x3F));
+                uint i0 = Unsafe.Add(ref encodingMap, (IntPtr)(i >> 10));
+                uint i1 = Unsafe.Add(ref encodingMap, (IntPtr)((i >> 4) & 0x3F));
 
-                dest[0] = i0;
-                dest[1] = i1;
+                uint result;
+
+                if (BitConverter.IsLittleEndian)
+                {
+                    result = (i0 | (i1 << 16));
+                }
+                else
+                {
+                    result = ((i0 << 16) | i1);
+                }
+
+                Unsafe.WriteUnaligned(dest, result);
             }
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]