Fix IsSupported guard check for use of Ssse3.Shuffle in Span.Reverse (#…

…69623) We were checking for SSE2 support and then using SSSE3 instructions. Fixes #68880.
dotnet · May 21, 2022 · 3b2f833 · 3b2f833
1 parent f832309
commit 3b2f833
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.Byte.cs b/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.Byte.cs
@@ -2374,7 +2374,7 @@ public static void Reverse(ref byte buf, nuint length)
                 buf = ref Unsafe.Add(ref buf, numIters * numElements);
                 length -= numIters * numElements * 2;
             }
-            else if (Sse2.IsSupported && (nuint)Vector128<byte>.Count * 2 <= length)
+            else if (Ssse3.IsSupported && (nuint)Vector128<byte>.Count * 2 <= length)
             {
                 Vector128<byte> reverseMask = Vector128.Create((byte)15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0);
                 nuint numElements = (nuint)Vector128<byte>.Count;

diff --git a/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.Char.cs b/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.Char.cs
@@ -2061,7 +2061,7 @@ public static void Reverse(ref char buf, nuint length)
                 bufByte = ref Unsafe.Add(ref bufByte, numIters * numElements);
                 length -= numIters * (nuint)Vector256<short>.Count * 2;
             }
-            else if (Sse2.IsSupported && (nuint)Vector128<short>.Count * 2 <= length)
+            else if (Ssse3.IsSupported && (nuint)Vector128<short>.Count * 2 <= length)
             {
                 Vector128<byte> reverseMask = Vector128.Create((byte)14, 15, 12, 13, 10, 11, 8, 9, 6, 7, 4, 5, 2, 3, 0, 1);
                 nuint numElements = (nuint)Vector128<byte>.Count;