Delete redundant DivMod implementation (#45652)

src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Utf8Formatter/FormattingHelpers.cs

@@ -149,32 +149,6 @@ public static void WriteTwoDecimalDigits(uint value, Span<byte> buffer, int star
 
  #endregion UTF-8 Helper methods
 
- #region Math Helper methods
-
- /// <summary>
- /// We don't have access to Math.DivRem, so this is a copy of the implementation.
- /// </summary>
- [MethodImpl(MethodImplOptions.AggressiveInlining)]
- public static ulong DivMod(ulong numerator, ulong denominator, out ulong modulo)
- {
- ulong div = numerator / denominator;
- modulo = numerator - (div * denominator);
- return div;
- }
-
- /// <summary>
- /// We don't have access to Math.DivRem, so this is a copy of the implementation.
- /// </summary>
- [MethodImpl(MethodImplOptions.AggressiveInlining)]
- public static uint DivMod(uint numerator, uint denominator, out uint modulo)
- {
- uint div = numerator / denominator;
- modulo = numerator - (div * denominator);
- return div;
- }
-
- #endregion Math Helper methods
-
  //
  // Enable use of ThrowHelper from TryFormat() routines without introducing dozens of non-code-coveraged "bytesWritten = 0; return false" boilerplate.
  //

src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Utf8Formatter/Utf8Formatter.TimeSpan.cs

@@ -70,7 +70,8 @@ public static bool TryFormat(TimeSpan value, Span<byte> destination, out int byt
  }
  }
 
- totalSecondsRemaining = FormattingHelpers.DivMod((ulong)Math.Abs(value.Ticks), TimeSpan.TicksPerSecond, out ulong fraction64);
+ ulong fraction64;
+ (totalSecondsRemaining, fraction64) = Math.DivRem((ulong)Math.Abs(value.Ticks), TimeSpan.TicksPerSecond);
  fraction = (uint)fraction64;
  }
 
@@ -114,7 +115,7 @@ public static bool TryFormat(TimeSpan value, Span<byte> destination, out int byt
  if (totalSecondsRemaining > 0)
  {
  // Only compute minutes if the TimeSpan has an absolute value of >= 1 minute.
- totalMinutesRemaining = FormattingHelpers.DivMod(totalSecondsRemaining, 60 /* seconds per minute */, out seconds);
+ (totalMinutesRemaining, seconds) = Math.DivRem(totalSecondsRemaining, 60 /* seconds per minute */);
  }
 
  Debug.Assert(seconds < 60);
@@ -124,7 +125,7 @@ public static bool TryFormat(TimeSpan value, Span<byte> destination, out int byt
  if (totalMinutesRemaining > 0)
  {
  // Only compute hours if the TimeSpan has an absolute value of >= 1 hour.
- totalHoursRemaining = FormattingHelpers.DivMod(totalMinutesRemaining, 60 /* minutes per hour */, out minutes);
+ (totalHoursRemaining, minutes) = Math.DivRem(totalMinutesRemaining, 60 /* minutes per hour */);
  }
 
  Debug.Assert(minutes < 60);
@@ -137,7 +138,7 @@ public static bool TryFormat(TimeSpan value, Span<byte> destination, out int byt
  if (totalHoursRemaining > 0)
  {
  // Only compute days if the TimeSpan has an absolute value of >= 1 day.
- days = FormattingHelpers.DivMod((uint)totalHoursRemaining, 24 /* hours per day */, out hours);
+ (days, hours) = Math.DivRem((uint)totalHoursRemaining, 24 /* hours per day */);
  }
 
  Debug.Assert(hours < 24);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/JsonWriterHelper.Date.cs

@@ -69,7 +69,7 @@ public static void TrimDateTimeOffset(Span<byte> buffer, out int bytesWritten)
  // Remove trailing zeros
  while (true)
  {
- uint quotient = DivMod(fraction, 10, out uint remainder);
+ (uint quotient, uint remainder) = DivRem(fraction, 10);
  if (remainder != 0)
  {
  break;
@@ -132,14 +132,13 @@ public static void TrimDateTimeOffset(Span<byte> buffer, out int bytesWritten)
  }
  }
 
- // We don't have access to System.Buffers.Text.FormattingHelpers.DivMod,
+ // We don't always have access to System.Math.DivRem,
  // so this is a copy of the implementation.
  [MethodImpl(MethodImplOptions.AggressiveInlining)]
- private static uint DivMod(uint numerator, uint denominator, out uint modulo)
+ public static (uint Quotient, uint Remainder) DivRem(uint left, uint right)
  {
- uint div = numerator / denominator;
- modulo = numerator - (div * denominator);
- return div;
+ uint quotient = left / right;
+ return (quotient, left - (quotient * right));
  }
  }
 }