Use unsigned version of ExtractNarrowingSaturate, avoid using MinAcross and use MaxPairwise instead

carlossanlop · carlossanlop · commit 191ec1fc90ea · 2020-07-15T13:14:17.000-07:00
diff --git a/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Transcoding.cs b/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Transcoding.cs
@@ -955,15 +955,15 @@ public static OperationStatus TranscodeToUtf8(char* pInputBuffer, int inputLengt
                             if (AdvSimd.IsSupported)
                             {
                                 Vector128<short> isUtf16DataNonAscii = AdvSimd.CompareTest(utf16Data, nonAsciiUtf16DataMask);
-                                bool hasNonAsciiDataInVector = AdvSimd.Arm64.MinAcross(isUtf16DataNonAscii).ToScalar() != 0;
+                                bool hasNonAsciiDataInVector = AdvSimd.Arm64.MaxPairwise(isUtf16DataNonAscii, isUtf16DataNonAscii).AsUInt64().ToScalar() != 0;
+
                                 if (hasNonAsciiDataInVector)
                                 {
                                     goto LoopTerminatedDueToNonAsciiDataInVectorLocal;
                                 }
 
-                                Vector64<sbyte> lower = AdvSimd.ExtractNarrowingSaturateLower(utf16Data);
-                                Vector128<sbyte> result = AdvSimd.ExtractNarrowingSaturateUpper(lower, utf16Data);
-                                AdvSimd.Store((ulong*)pOutputBuffer, result.AsUInt64());
+                                Vector64<byte> lower = AdvSimd.ExtractNarrowingSaturateUnsignedLower(utf16Data);
+                                AdvSimd.Store(pOutputBuffer, lower);
                             }
                             else
                             {

Original file line number	Diff line number	Diff line change
`@@ -955,15 +955,15 @@ public static OperationStatus TranscodeToUtf8(char* pInputBuffer, int inputLengt`
`955`	`955`	`if (AdvSimd.IsSupported)`
`956`	`956`	`{`
`957`	`957`	`Vector128<short> isUtf16DataNonAscii = AdvSimd.CompareTest(utf16Data, nonAsciiUtf16DataMask);`
`958`		`- bool hasNonAsciiDataInVector = AdvSimd.Arm64.MinAcross(isUtf16DataNonAscii).ToScalar() != 0;`
	`958`	`+ bool hasNonAsciiDataInVector = AdvSimd.Arm64.MaxPairwise(isUtf16DataNonAscii, isUtf16DataNonAscii).AsUInt64().ToScalar() != 0;`
	`959`	`+`
`959`	`960`	`if (hasNonAsciiDataInVector)`
`960`	`961`	`{`
`961`	`962`	`goto LoopTerminatedDueToNonAsciiDataInVectorLocal;`
`962`	`963`	`}`
`963`	`964`
`964`		`- Vector64<sbyte> lower = AdvSimd.ExtractNarrowingSaturateLower(utf16Data);`
`965`		`- Vector128<sbyte> result = AdvSimd.ExtractNarrowingSaturateUpper(lower, utf16Data);`
`966`		`- AdvSimd.Store((ulong*)pOutputBuffer, result.AsUInt64());`
	`965`	`+ Vector64<byte> lower = AdvSimd.ExtractNarrowingSaturateUnsignedLower(utf16Data);`
	`966`	`+ AdvSimd.Store(pOutputBuffer, lower);`
`967`	`967`	`}`
`968`	`968`	`else`
`969`	`969`	`{`