Use TryParseUInt32HexNumberStyle directly from Guid.TryParse (#44918)

Skips public entry points of uint.TryParse, including argument validation, branches for style, but most impactfully fetching the current number culture when it won't actually be needed.
dotnet · Nov 20, 2020 · f22d7c5 · f22d7c5
1 parent a61b054
commit f22d7c5
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Showing 2 changed files with 7 additions and 7 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/System/Guid.cs b/src/libraries/System.Private.CoreLib/src/System/Guid.cs
@@ -362,7 +362,7 @@ private static bool TryParseGuid(ReadOnlySpan<char> guidString, ref GuidResult r
         }
 
         // Two helpers used for parsing components:
-        // - uint.TryParse(..., NumberStyles.AllowHexSpecifier, ...)
+        // - Number.TryParseUInt32HexNumberStyle(..., NumberStyles.AllowHexSpecifier, ...)
         //       Used when we expect the entire provided span to be filled with and only with hex digits and no overflow is possible
         // - TryParseHex
         //       Used when the component may have an optional '+' and "0x" prefix, when it may overflow, etc.
@@ -421,7 +421,7 @@ private static bool TryParseExactD(ReadOnlySpan<char> guidString, ref GuidResult
                             // _f, _g must be stored as a big-endian ushort
                             result._fg = BitConverter.IsLittleEndian ? BinaryPrimitives.ReverseEndianness((ushort)uintTmp) : (ushort)uintTmp;
 
-                            if (uint.TryParse(guidString.Slice(28, 8), NumberStyles.AllowHexSpecifier, null, out uintTmp)) // _h, _i, _j, _k
+                            if (Number.TryParseUInt32HexNumberStyle(guidString.Slice(28, 8), NumberStyles.AllowHexSpecifier, out uintTmp) == Number.ParsingStatus.OK) // _h, _i, _j, _k
                             {
                                 // _h, _i, _j, _k must be stored as a big-endian uint
                                 result._hijk = BitConverter.IsLittleEndian ? BinaryPrimitives.ReverseEndianness(uintTmp) : uintTmp;
@@ -447,20 +447,20 @@ private static bool TryParseExactN(ReadOnlySpan<char> guidString, ref GuidResult
                 return false;
             }
 
-            if (uint.TryParse(guidString.Slice(0, 8), NumberStyles.AllowHexSpecifier, null, out result._a) && // _a
-                uint.TryParse(guidString.Slice(8, 8), NumberStyles.AllowHexSpecifier, null, out uint uintTmp)) // _b, _c
+            if (Number.TryParseUInt32HexNumberStyle(guidString.Slice(0, 8), NumberStyles.AllowHexSpecifier, out result._a) == Number.ParsingStatus.OK && // _a
+                Number.TryParseUInt32HexNumberStyle(guidString.Slice(8, 8), NumberStyles.AllowHexSpecifier, out uint uintTmp) == Number.ParsingStatus.OK) // _b, _c
             {
                 // _b, _c are independently in machine-endian order
                 if (BitConverter.IsLittleEndian) { uintTmp = BitOperations.RotateRight(uintTmp, 16); }
                 result._bc = uintTmp;
 
-                if (uint.TryParse(guidString.Slice(16, 8), NumberStyles.AllowHexSpecifier, null, out uintTmp)) // _d, _e, _f, _g
+                if (Number.TryParseUInt32HexNumberStyle(guidString.Slice(16, 8), NumberStyles.AllowHexSpecifier, out uintTmp) == Number.ParsingStatus.OK) // _d, _e, _f, _g
                 {
                     // _d, _e, _f, _g must be stored as a big-endian uint
                     if (BitConverter.IsLittleEndian) { uintTmp = BinaryPrimitives.ReverseEndianness(uintTmp); }
                     result._defg = uintTmp;
 
-                    if (uint.TryParse(guidString.Slice(24, 8), NumberStyles.AllowHexSpecifier, null, out uintTmp)) // _h, _i, _j, _k
+                    if (Number.TryParseUInt32HexNumberStyle(guidString.Slice(24, 8), NumberStyles.AllowHexSpecifier, out uintTmp) == Number.ParsingStatus.OK) // _h, _i, _j, _k
                     {
                         // _h, _i, _j, _k must be stored as big-endian uint
                         if (BitConverter.IsLittleEndian) { uintTmp = BinaryPrimitives.ReverseEndianness(uintTmp); }

diff --git a/src/libraries/System.Private.CoreLib/src/System/Number.Parsing.cs b/src/libraries/System.Private.CoreLib/src/System/Number.Parsing.cs
@@ -1096,7 +1096,7 @@ internal static ParsingStatus TryParseUInt32IntegerStyle(ReadOnlySpan<char> valu
         }
 
         /// <summary>Parses uint limited to styles that make up NumberStyles.HexNumber.</summary>
-        private static ParsingStatus TryParseUInt32HexNumberStyle(ReadOnlySpan<char> value, NumberStyles styles, out uint result)
+        internal static ParsingStatus TryParseUInt32HexNumberStyle(ReadOnlySpan<char> value, NumberStyles styles, out uint result)
         {
             Debug.Assert((styles & ~NumberStyles.HexNumber) == 0, "Only handles subsets of HexNumber format");