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Improve char.ToUpperInvariant / ToLowerInvariant perf #35194

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Merged
merged 1 commit into from
Apr 20, 2020
Merged

Improve char.ToUpperInvariant / ToLowerInvariant perf #35194

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10 changes: 2 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Char.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -354,10 +354,7 @@ public static char ToUpper(char c)
}

// Converts a character to upper-case for invariant culture.
public static char ToUpperInvariant(char c)
{
return TextInfo.Invariant.ToUpper(c);
}
public static char ToUpperInvariant(char c) => TextInfo.ToUpperInvariant(c);

/*===================================ToLower====================================
**
Expand All @@ -383,10 +380,7 @@ public static char ToLower(char c)
}

// Converts a character to lower-case for invariant culture.
public static char ToLowerInvariant(char c)
{
return TextInfo.Invariant.ToLower(c);
}
public static char ToLowerInvariant(char c) => TextInfo.ToLowerInvariant(c);

//
// IConvertible implementation
Expand Down
39 changes: 30 additions & 9 deletions src/libraries/System.Private.CoreLib/src/System/Globalization/TextInfo.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -151,14 +151,24 @@ public string ListSeparator
/// </summary>
public char ToLower(char c)
{
if (GlobalizationMode.Invariant || (IsAscii(c) && IsAsciiCasingSameAsInvariant))
if (GlobalizationMode.Invariant || (UnicodeUtility.IsAsciiCodePoint(c) && IsAsciiCasingSameAsInvariant))
{
return ToLowerAsciiInvariant(c);
}

return ChangeCase(c, toUpper: false);
}

internal static char ToLowerInvariant(char c)
{
if (GlobalizationMode.Invariant || UnicodeUtility.IsAsciiCodePoint(c))
{
return ToLowerAsciiInvariant(c);
}

return Invariant.ChangeCase(c, toUpper: false);
}

public string ToLower(string str)
{
if (str == null)
Expand Down Expand Up @@ -528,11 +538,13 @@ internal static void ToUpperAsciiInvariant(ReadOnlySpan<char> source, Span<char>
}
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static char ToLowerAsciiInvariant(char c)
{
if ((uint)(c - 'A') <= (uint)('Z' - 'A'))
if (UnicodeUtility.IsInRangeInclusive(c, 'A', 'Z'))
{
c = (char)(c | 0x20);
// on x86, extending BYTE -> DWORD is more efficient than WORD -> DWORD
c = (char)(byte)(c | 0x20);
}
return c;
}
Expand All @@ -543,14 +555,24 @@ private static char ToLowerAsciiInvariant(char c)
/// </summary>
public char ToUpper(char c)
{
if (GlobalizationMode.Invariant || (IsAscii(c) && IsAsciiCasingSameAsInvariant))
if (GlobalizationMode.Invariant || (UnicodeUtility.IsAsciiCodePoint(c) && IsAsciiCasingSameAsInvariant))
{
return ToUpperAsciiInvariant(c);
}

return ChangeCase(c, toUpper: true);
}

internal static char ToUpperInvariant(char c)
{
if (GlobalizationMode.Invariant || UnicodeUtility.IsAsciiCodePoint(c))
{
return ToUpperAsciiInvariant(c);
}

return Invariant.ChangeCase(c, toUpper: true);
}

public string ToUpper(string str)
{
if (str == null)
Expand All @@ -566,17 +588,16 @@ public string ToUpper(string str)
return ChangeCaseCommon<ToUpperConversion>(str);
}

internal static char ToUpperAsciiInvariant(char c)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static char ToUpperAsciiInvariant(char c)
{
if ((uint)(c - 'a') <= (uint)('z' - 'a'))
if (UnicodeUtility.IsInRangeInclusive(c, 'a', 'z'))
{
c = (char)(c & ~0x20);
c = (char)(c & 0x5F); // = low 7 bits of ~0x20
}
return c;
}

private static bool IsAscii(char c) => c < 0x80;

private bool IsAsciiCasingSameAsInvariant
{
[MethodImpl(MethodImplOptions.AggressiveInlining)]
Expand Down