[wasm] Use packedsimd in hexconverter

src/libraries/Common/src/System/HexConverter.cs

@@ -8,6 +8,7 @@
 using System.Runtime.InteropServices;
 using System.Runtime.Intrinsics;
 using System.Runtime.Intrinsics.Arm;
+using System.Runtime.Intrinsics.Wasm;
 using System.Runtime.Intrinsics.X86;
 using System.Text;
 using System.Text.Unicode;
@@ -243,7 +244,7 @@ public static char ToCharLower(int value)
         public static bool TryDecodeFromUtf16(ReadOnlySpan<char> chars, Span<byte> bytes, out int charsProcessed)
         {
 #if SYSTEM_PRIVATE_CORELIB
-            if (BitConverter.IsLittleEndian && (Ssse3.IsSupported || AdvSimd.Arm64.IsSupported) &&
+            if (BitConverter.IsLittleEndian && (Ssse3.IsSupported || AdvSimd.Arm64.IsSupported || PackedSimd.IsSupported) &&
                 chars.Length >= Vector128<ushort>.Count * 2)
             {
                 return TryDecodeFromUtf16_Vector128(chars, bytes, out charsProcessed);
@@ -255,9 +256,10 @@ public static bool TryDecodeFromUtf16(ReadOnlySpan<char> chars, Span<byte> bytes
 #if SYSTEM_PRIVATE_CORELIB
         [CompExactlyDependsOn(typeof(AdvSimd.Arm64))]
         [CompExactlyDependsOn(typeof(Ssse3))]
+        [CompExactlyDependsOn(typeof(PackedSimd))]
         public static bool TryDecodeFromUtf16_Vector128(ReadOnlySpan<char> chars, Span<byte> bytes, out int charsProcessed)
         {
-            Debug.Assert(Ssse3.IsSupported || AdvSimd.Arm64.IsSupported);
+            Debug.Assert(Ssse3.IsSupported || AdvSimd.Arm64.IsSupported || PackedSimd.IsSupported);
             Debug.Assert(chars.Length <= bytes.Length * 2);
             Debug.Assert(chars.Length % 2 == 0);
             Debug.Assert(chars.Length >= Vector128<ushort>.Count * 2);
@@ -314,6 +316,12 @@ public static bool TryDecodeFromUtf16_Vector128(ReadOnlySpan<char> chars, Span<b
                     even = AdvSimd.ShiftLeftLogical(even, 4).AsInt16();
                     output = AdvSimd.AddSaturate(even, odd).AsByte();
                 }
+                else if (PackedSimd.IsSupported)
+                {
+                    Vector128<byte> shiftedNibbles = PackedSimd.ShiftLeft(nibbles, 4);
+                    Vector128<byte> zipped = PackedSimd.BitwiseSelect(nibbles, shiftedNibbles, Vector128.Create((ushort)0xFF00).AsByte());
+                    output = PackedSimd.AddPairwiseWidening(zipped).AsByte();
+                }
                 else
                 {
                     // We explicitly recheck each IsSupported query to ensure that the trimmer can see which paths are live/dead

src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector128.cs

@@ -4296,12 +4296,17 @@ internal static Vector128<byte> UnpackHigh(Vector128<byte> left, Vector128<byte>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         [CompExactlyDependsOn(typeof(AdvSimd.Arm64))]
         [CompExactlyDependsOn(typeof(Sse2))]
+        [CompExactlyDependsOn(typeof(PackedSimd))]
         internal static Vector128<byte> AddSaturate(Vector128<byte> left, Vector128<byte> right)
         {
             if (Sse2.IsSupported)
             {
                 return Sse2.AddSaturate(left, right);
             }
+            else if (PackedSimd.IsSupported)
+            {
+                return PackedSimd.AddSaturate(left, right);
+            }
             else if (!AdvSimd.Arm64.IsSupported)
             {
                 ThrowHelper.ThrowNotSupportedException();
@@ -4312,12 +4317,17 @@ internal static Vector128<byte> AddSaturate(Vector128<byte> left, Vector128<byte
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         [CompExactlyDependsOn(typeof(AdvSimd.Arm64))]
         [CompExactlyDependsOn(typeof(Sse2))]
+        [CompExactlyDependsOn(typeof(PackedSimd))]
         internal static Vector128<byte> SubtractSaturate(Vector128<byte> left, Vector128<byte> right)
         {
             if (Sse2.IsSupported)
             {
                 return Sse2.SubtractSaturate(left, right);
             }
+            else if (PackedSimd.IsSupported)
+            {
+                return PackedSimd.SubtractSaturate(left, right);
+            }
             else if (!AdvSimd.Arm64.IsSupported)
             {
                 ThrowHelper.ThrowNotSupportedException();
@@ -4328,12 +4338,17 @@ internal static Vector128<byte> SubtractSaturate(Vector128<byte> left, Vector128
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         [CompExactlyDependsOn(typeof(AdvSimd.Arm64))]
         [CompExactlyDependsOn(typeof(Sse2))]
+        [CompExactlyDependsOn(typeof(PackedSimd))]
         internal static Vector128<ushort> AddSaturate(Vector128<ushort> left, Vector128<ushort> right)
         {
             if (Sse2.IsSupported)
             {
                 return Sse2.AddSaturate(left, right);
             }
+            else if (PackedSimd.IsSupported)
+            {
+                return PackedSimd.AddSaturate(left, right);
+            }
             else if (!AdvSimd.Arm64.IsSupported)
             {
                 ThrowHelper.ThrowNotSupportedException();