Optimize ToString() for byte, ushort, uint and ulong (dotnet/coreclr#…

…27056) Commit migrated from dotnet/coreclr@020639b
EgorBo · Oct 9, 2019 · 9282775 · 9282775
1 parent a8951de
commit 9282775
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Showing 5 changed files with 14 additions and 22 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/System/Byte.cs b/src/libraries/System.Private.CoreLib/src/System/Byte.cs
@@ -166,7 +166,7 @@ private static bool TryParse(ReadOnlySpan<char> s, NumberStyles style, NumberFor
 
         public override string ToString()
         {
-            return Number.FormatUInt32(m_value, null, null);
+            return Number.UInt32ToDecStr(m_value, -1);
         }
 
         public string ToString(string? format)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Number.Formatting.cs b/src/libraries/System.Private.CoreLib/src/System/Number.Formatting.cs
@@ -1205,10 +1205,8 @@ private static unsafe void UInt32ToNumber(uint value, ref NumberBuffer number)
         {
             while (--digits >= 0 || value != 0)
             {
-                // TODO https://github.com/dotnet/coreclr/issues/3439
-                uint newValue = value / 10;
-                *(--bufferEnd) = (byte)(value - (newValue * 10) + '0');
-                value = newValue;
+                value = Math.DivRem(value, 10, out uint remainder);
+                *(--bufferEnd) = (byte)(remainder + '0');
             }
             return bufferEnd;
         }
@@ -1217,15 +1215,13 @@ private static unsafe void UInt32ToNumber(uint value, ref NumberBuffer number)
         {
             while (--digits >= 0 || value != 0)
             {
-                // TODO https://github.com/dotnet/coreclr/issues/3439
-                uint newValue = value / 10;
-                *(--bufferEnd) = (char)(value - (newValue * 10) + '0');
-                value = newValue;
+                value = Math.DivRem(value, 10, out uint remainder);
+                *(--bufferEnd) = (char)(remainder + '0');
             }
             return bufferEnd;
         }
 
-        private static unsafe string UInt32ToDecStr(uint value, int digits)
+        internal static unsafe string UInt32ToDecStr(uint value, int digits)
         {
             int bufferLength = Math.Max(digits, FormattingHelpers.CountDigits(value));
 
@@ -1243,10 +1239,8 @@ private static unsafe string UInt32ToDecStr(uint value, int digits)
                 {
                     do
                     {
-                        // TODO https://github.com/dotnet/coreclr/issues/3439
-                        uint div = value / 10;
-                        *(--p) = (char)('0' + value - (div * 10));
-                        value = div;
+                        value = Math.DivRem(value, 10, out uint remainder);
+                        *(--p) = (char)(remainder + '0');
                     }
                     while (value != 0);
                 }
@@ -1276,10 +1270,8 @@ private static unsafe bool TryUInt32ToDecStr(uint value, int digits, Span<char>
                 {
                     do
                     {
-                        // TODO https://github.com/dotnet/coreclr/issues/3439
-                        uint div = value / 10;
-                        *(--p) = (char)('0' + value - (div * 10));
-                        value = div;
+                        value = Math.DivRem(value, 10, out uint remainder);
+                        *(--p) = (char)(remainder + '0');
                     }
                     while (value != 0);
                 }
@@ -1481,7 +1473,7 @@ private static unsafe void UInt64ToNumber(ulong value, ref NumberBuffer number)
             number.CheckConsistency();
         }
 
-        private static unsafe string UInt64ToDecStr(ulong value, int digits)
+        internal static unsafe string UInt64ToDecStr(ulong value, int digits)
         {
             if (digits < 1)
                 digits = 1;

diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt16.cs b/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
@@ -68,7 +68,7 @@ public override int GetHashCode()
         // Converts the current value to a String in base-10 with no extra padding.
         public override string ToString()
         {
-            return Number.FormatUInt32(m_value, null, null);
+            return Number.UInt32ToDecStr(m_value, -1);
         }
 
         public string ToString(IFormatProvider? provider)

diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt32.cs b/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
@@ -78,7 +78,7 @@ public override int GetHashCode()
         // The base 10 representation of the number with no extra padding.
         public override string ToString()
         {
-            return Number.FormatUInt32(m_value, null, null);
+            return Number.UInt32ToDecStr(m_value, -1);
         }
 
         public string ToString(IFormatProvider? provider)

diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt64.cs b/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
@@ -77,7 +77,7 @@ public override int GetHashCode()
 
         public override string ToString()
         {
-            return Number.FormatUInt64(m_value, null, null);
+            return Number.UInt64ToDecStr(m_value, -1);
         }
 
         public string ToString(IFormatProvider? provider)