Optimize DateOnly, TimeOnly, ISOWeek (#111244)

* Optimize DateOnly, TimeOnly, ISOWeek

* Address PR feedback

Author: pentp

src/libraries/System.Private.CoreLib/src/System/DateOnly.cs

@@ -21,21 +21,21 @@ public readonly struct DateOnly
           ISpanParsable<DateOnly>,
           IUtf8SpanFormattable
     {
-        private readonly int _dayNumber;
+        private readonly uint _dayNumber;
 
         // Maps to Jan 1st year 1
         private const int MinDayNumber = 0;
 
         // Maps to December 31 year 9999.
         private const int MaxDayNumber = DateTime.DaysTo10000 - 1;
 
-        private static int DayNumberFromDateTime(DateTime dt) => (int)((ulong)dt.Ticks / TimeSpan.TicksPerDay);
+        private static uint DayNumberFromDateTime(DateTime dt) => (uint)((ulong)dt.Ticks / TimeSpan.TicksPerDay);
 
-        internal DateTime GetEquivalentDateTime() => DateTime.UnsafeCreate(_dayNumber * TimeSpan.TicksPerDay);
+        internal DateTime GetEquivalentDateTime() => DateTime.CreateUnchecked(_dayNumber * TimeSpan.TicksPerDay);
 
-        private DateOnly(int dayNumber)
+        private DateOnly(uint dayNumber)
         {
-            Debug.Assert((uint)dayNumber <= MaxDayNumber);
+            Debug.Assert(dayNumber <= MaxDayNumber);
             _dayNumber = dayNumber;
         }
 
@@ -77,7 +77,7 @@ public static DateOnly FromDayNumber(int dayNumber)
                 ThrowHelper.ThrowArgumentOutOfRange_DayNumber(dayNumber);
             }
 
-            return new DateOnly(dayNumber);
+            return new DateOnly((uint)dayNumber);
         }
 
         /// <summary>
@@ -98,7 +98,7 @@ public static DateOnly FromDayNumber(int dayNumber)
         /// <summary>
         /// Gets the day of the week represented by this instance.
         /// </summary>
-        public DayOfWeek DayOfWeek => (DayOfWeek)(((uint)_dayNumber + 1) % 7);
+        public DayOfWeek DayOfWeek => (DayOfWeek)((_dayNumber + 1) % 7);
 
         /// <summary>
         /// Gets the day of the year represented by this instance.
@@ -108,7 +108,7 @@ public static DateOnly FromDayNumber(int dayNumber)
         /// <summary>
         /// Gets the number of days since January 1, 0001 in the Proleptic Gregorian calendar represented by this instance.
         /// </summary>
-        public int DayNumber => _dayNumber;
+        public int DayNumber => (int)_dayNumber;
 
         /// <summary>
         /// Adds the specified number of days to the value of this instance.
@@ -120,8 +120,8 @@ public static DateOnly FromDayNumber(int dayNumber)
         /// </exception>
         public DateOnly AddDays(int value)
         {
-            int newDayNumber = _dayNumber + value;
-            if ((uint)newDayNumber > MaxDayNumber)
+            uint newDayNumber = _dayNumber + (uint)value;
+            if (newDayNumber > MaxDayNumber)
             {
                 ThrowOutOfRange();
             }
@@ -214,15 +214,15 @@ public void Deconstruct(out int year, out int month, out int day)
         /// </summary>
         /// <param name="time">The time of the day.</param>
         /// <returns>The DateTime instance composed of the date of the current DateOnly instance and the time specified by the input time.</returns>
-        public DateTime ToDateTime(TimeOnly time) => new DateTime(_dayNumber * TimeSpan.TicksPerDay + time.Ticks);
+        public DateTime ToDateTime(TimeOnly time) => DateTime.CreateUnchecked(_dayNumber * TimeSpan.TicksPerDay + time.Ticks);
 
         /// <summary>
         /// Returns a DateTime instance with the specified input kind that is set to the date of this DateOnly instance and the time of specified input time.
         /// </summary>
         /// <param name="time">The time of the day.</param>
         /// <param name="kind">One of the enumeration values that indicates whether ticks specifies a local time, Coordinated Universal Time (UTC), or neither.</param>
         /// <returns>The DateTime instance composed of the date of the current DateOnly instance and the time specified by the input time.</returns>
-        public DateTime ToDateTime(TimeOnly time, DateTimeKind kind) => new DateTime(_dayNumber * TimeSpan.TicksPerDay + time.Ticks, kind);
+        public DateTime ToDateTime(TimeOnly time, DateTimeKind kind) => DateTime.SpecifyKind(ToDateTime(time), kind);
 
         /// <summary>
         /// Returns a DateOnly instance that is set to the date part of the specified dateTime.
@@ -272,7 +272,7 @@ public int CompareTo(object? value)
         /// Returns the hash code for this instance.
         /// </summary>
         /// <returns>A 32-bit signed integer hash code.</returns>
-        public override int GetHashCode() => _dayNumber;
+        public override int GetHashCode() => (int)_dayNumber;
 
         private const ParseFlags ParseFlagsDateMask = ParseFlags.HaveHour | ParseFlags.HaveMinute | ParseFlags.HaveSecond | ParseFlags.HaveTime | ParseFlags.TimeZoneUsed |
                                                       ParseFlags.TimeZoneUtc | ParseFlags.CaptureOffset | ParseFlags.UtcSortPattern;
@@ -498,12 +498,12 @@ private static ParseFailureKind TryParseExactInternal(ReadOnlySpan<char> s, Read
                 {
                     case 'o':
                         format = OFormat;
-                        provider = CultureInfo.InvariantCulture.DateTimeFormat;
+                        provider = DateTimeFormat.InvariantFormatInfo;
                         break;
 
                     case 'r':
                         format = RFormat;
-                        provider = CultureInfo.InvariantCulture.DateTimeFormat;
+                        provider = DateTimeFormat.InvariantFormatInfo;
                         break;
                 }
             }
@@ -575,12 +575,12 @@ private static ParseFailureKind TryParseExactInternal(ReadOnlySpan<char> s, stri
                     {
                         case 'o':
                             format = OFormat;
-                            dtfiToUse = CultureInfo.InvariantCulture.DateTimeFormat;
+                            dtfiToUse = DateTimeFormat.InvariantFormatInfo;
                             break;
 
                         case 'r':
                             format = RFormat;
-                            dtfiToUse = CultureInfo.InvariantCulture.DateTimeFormat;
+                            dtfiToUse = DateTimeFormat.InvariantFormatInfo;
                             break;
                     }
                 }
@@ -718,7 +718,7 @@ private static void ThrowOnError(ParseFailureKind result, ReadOnlySpan<char> s)
         /// The DateOnly object will be formatted in short form.
         /// </summary>
         /// <returns>A string that contains the short date string representation of the current DateOnly object.</returns>
-        public override string ToString() => ToString("d");
+        public override string ToString() => DateTimeFormat.Format(GetEquivalentDateTime(), "d", null);
 
         /// <summary>
         /// Converts the value of the current DateOnly object to its equivalent string representation using the specified format and the formatting conventions of the current culture.
@@ -732,7 +732,7 @@ private static void ThrowOnError(ParseFailureKind result, ReadOnlySpan<char> s)
         /// </summary>
         /// <param name="provider">An object that supplies culture-specific formatting information.</param>
         /// <returns>A string representation of value of the current DateOnly object as specified by provider.</returns>
-        public string ToString(IFormatProvider? provider) => ToString("d", provider);
+        public string ToString(IFormatProvider? provider) => DateTimeFormat.Format(GetEquivalentDateTime(), "d", provider);
 
         /// <summary>
         /// Converts the value of the current DateOnly object to its equivalent string representation using the specified culture-specific format information.
@@ -753,13 +753,13 @@ public string ToString([StringSyntax(StringSyntaxAttribute.DateOnlyFormat)] stri
                 {
                     'o' => string.Create(10, this, (destination, value) =>
                            {
-                               DateTimeFormat.TryFormatDateOnlyO(value.Year, value.Month, value.Day, destination, out int charsWritten);
+                               DateTimeFormat.TryFormatDateOnlyO(value, destination, out int charsWritten);
                                Debug.Assert(charsWritten == destination.Length);
                            }),
 
                     'r' => string.Create(16, this, (destination, value) =>
                            {
-                               DateTimeFormat.TryFormatDateOnlyR(value.DayOfWeek, value.Year, value.Month, value.Day, destination, out int charsWritten);
+                               DateTimeFormat.TryFormatDateOnlyR(value, destination, out int charsWritten);
                                Debug.Assert(charsWritten == destination.Length);
                            }),
 
@@ -801,10 +801,10 @@ private bool TryFormatCore<TChar>(Span<TChar> destination, out int charsWritten,
                 switch (format[0] | 0x20)
                 {
                     case 'o':
-                        return DateTimeFormat.TryFormatDateOnlyO(Year, Month, Day, destination, out charsWritten);
+                        return DateTimeFormat.TryFormatDateOnlyO(this, destination, out charsWritten);
 
                     case 'r':
-                        return DateTimeFormat.TryFormatDateOnlyR(DayOfWeek, Year, Month, Day, destination, out charsWritten);
+                        return DateTimeFormat.TryFormatDateOnlyR(this, destination, out charsWritten);
 
                     case 'm':
                     case 'd':

src/libraries/System.Private.CoreLib/src/System/DateTime.cs

@@ -148,10 +148,11 @@ public DateTime(long ticks)
 
         private DateTime(ulong dateData)
         {
-            this._dateData = dateData;
+            Debug.Assert((dateData & TicksMask) <= MaxTicks);
+            _dateData = dateData;
         }
 
-        internal static DateTime UnsafeCreate(long ticks) => new DateTime((ulong)ticks);
+        internal static DateTime CreateUnchecked(long ticks) => new DateTime((ulong)ticks);
 
         public DateTime(long ticks, DateTimeKind kind)
         {
@@ -1086,7 +1087,7 @@ private static ulong DateToTicks(int year, int month, int day)
                 ThrowHelper.ThrowArgumentOutOfRange_BadYearMonthDay();
             }
 
-            ReadOnlySpan<uint> days = IsLeapYear(year) ? DaysToMonth366 : DaysToMonth365;
+            ReadOnlySpan<uint> days = RuntimeHelpers.IsKnownConstant(month) && month == 1 || IsLeapYear(year) ? DaysToMonth366 : DaysToMonth365;
             if ((uint)day > days[month] - days[month - 1])
             {
                 ThrowHelper.ThrowArgumentOutOfRange_BadYearMonthDay();

src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs

@@ -59,8 +59,8 @@ public readonly partial struct DateTimeOffset
 
         // Static Fields
         public static readonly DateTimeOffset MinValue;
-        public static readonly DateTimeOffset MaxValue = new DateTimeOffset(0, DateTime.UnsafeCreate(DateTime.MaxTicks));
-        public static readonly DateTimeOffset UnixEpoch = new DateTimeOffset(0, DateTime.UnsafeCreate(DateTime.UnixEpochTicks));
+        public static readonly DateTimeOffset MaxValue = new DateTimeOffset(0, DateTime.CreateUnchecked(DateTime.MaxTicks));
+        public static readonly DateTimeOffset UnixEpoch = new DateTimeOffset(0, DateTime.CreateUnchecked(DateTime.UnixEpochTicks));
 
         // Instance Fields
         private readonly DateTime _dateTime;
@@ -167,7 +167,7 @@ public DateTimeOffset(int year, int month, int day, int hour, int minute, int se
             : this(year, month, day, hour, minute, second, offset)
         {
             if ((uint)millisecond >= TimeSpan.MillisecondsPerSecond) DateTime.ThrowMillisecondOutOfRange();
-            _dateTime = DateTime.UnsafeCreate(UtcTicks + (uint)millisecond * (uint)TimeSpan.TicksPerMillisecond);
+            _dateTime = DateTime.CreateUnchecked(UtcTicks + (uint)millisecond * (uint)TimeSpan.TicksPerMillisecond);
         }
 
         // Constructs a DateTimeOffset from a given year, month, day, hour,
@@ -252,7 +252,7 @@ public DateTimeOffset(int year, int month, int day, int hour, int minute, int se
             : this(year, month, day, hour, minute, second, millisecond, offset)
         {
             if ((uint)microsecond >= TimeSpan.MicrosecondsPerMillisecond) DateTime.ThrowMicrosecondOutOfRange();
-            _dateTime = DateTime.UnsafeCreate(UtcTicks + (uint)microsecond * (uint)TimeSpan.TicksPerMicrosecond);
+            _dateTime = DateTime.CreateUnchecked(UtcTicks + (uint)microsecond * (uint)TimeSpan.TicksPerMicrosecond);
         }
 
         /// <summary>
@@ -326,14 +326,14 @@ public DateTimeOffset(int year, int month, int day, int hour, int minute, int se
             : this(year, month, day, hour, minute, second, millisecond, calendar, offset)
         {
             if ((uint)microsecond >= TimeSpan.MicrosecondsPerMillisecond) DateTime.ThrowMicrosecondOutOfRange();
-            _dateTime = DateTime.UnsafeCreate(UtcTicks + (uint)microsecond * (uint)TimeSpan.TicksPerMicrosecond);
+            _dateTime = DateTime.CreateUnchecked(UtcTicks + (uint)microsecond * (uint)TimeSpan.TicksPerMicrosecond);
         }
 
         public static DateTimeOffset UtcNow => new DateTimeOffset(0, DateTime.SpecifyKind(DateTime.UtcNow, DateTimeKind.Unspecified));
 
         public DateTime DateTime => ClockDateTime;
 
-        public DateTime UtcDateTime => DateTime.UnsafeCreate((long)(_dateTime._dateData | DateTime.KindUtc));
+        public DateTime UtcDateTime => DateTime.CreateUnchecked((long)(_dateTime._dateData | DateTime.KindUtc));
 
         public DateTime LocalDateTime => UtcDateTime.ToLocalTime();
 
@@ -346,7 +346,7 @@ public DateTimeOffset(int year, int month, int day, int hour, int minute, int se
         // The clock or visible time represented. This is just a wrapper around the internal date because this is
         // the chosen storage mechanism. Going through this helper is good for readability and maintainability.
         // This should be used for display but not identity.
-        private DateTime ClockDateTime => DateTime.UnsafeCreate(UtcTicks + _offsetMinutes * TimeSpan.TicksPerMinute);
+        private DateTime ClockDateTime => DateTime.CreateUnchecked(UtcTicks + _offsetMinutes * TimeSpan.TicksPerMinute);
 
         // Returns the date part of this DateTimeOffset. The resulting value
         // corresponds to this DateTimeOffset with the time-of-day part set to
@@ -587,12 +587,11 @@ public static DateTimeOffset FromUnixTimeSeconds(long seconds)
         {
             if (seconds < UnixMinSeconds || seconds > UnixMaxSeconds)
             {
-                throw new ArgumentOutOfRangeException(nameof(seconds),
-                    SR.Format(SR.ArgumentOutOfRange_Range, UnixMinSeconds, UnixMaxSeconds));
+                ThrowHelper.ThrowArgumentOutOfRange_Range(nameof(seconds), seconds, UnixMinSeconds, UnixMaxSeconds);
             }
 
             long ticks = seconds * TimeSpan.TicksPerSecond + DateTime.UnixEpochTicks;
-            return new DateTimeOffset(0, DateTime.UnsafeCreate(ticks));
+            return new DateTimeOffset(0, DateTime.CreateUnchecked(ticks));
         }
 
         public static DateTimeOffset FromUnixTimeMilliseconds(long milliseconds)
@@ -602,12 +601,11 @@ public static DateTimeOffset FromUnixTimeMilliseconds(long milliseconds)
 
             if (milliseconds < MinMilliseconds || milliseconds > MaxMilliseconds)
             {
-                throw new ArgumentOutOfRangeException(nameof(milliseconds),
-                    SR.Format(SR.ArgumentOutOfRange_Range, MinMilliseconds, MaxMilliseconds));
+                ThrowHelper.ThrowArgumentOutOfRange_Range(nameof(milliseconds), milliseconds, MinMilliseconds, MaxMilliseconds);
             }
 
             long ticks = milliseconds * TimeSpan.TicksPerMillisecond + DateTime.UnixEpochTicks;
-            return new DateTimeOffset(0, DateTime.UnsafeCreate(ticks));
+            return new DateTimeOffset(0, DateTime.CreateUnchecked(ticks));
         }
 
         // ----- SECTION: private serialization instance methods  ----------------*
@@ -788,7 +786,7 @@ private static DateTimeOffset ToLocalTime(DateTime utcDateTime, bool throwOnOver
                 localTicks = localTicks < DateTime.MinTicks ? DateTime.MinTicks : DateTime.MaxTicks;
             }
 
-            return CreateValidateOffset(DateTime.UnsafeCreate(localTicks), offset);
+            return CreateValidateOffset(DateTime.CreateUnchecked(localTicks), offset);
         }
 
         public override string ToString() =>
@@ -947,7 +945,7 @@ private static DateTime ValidateDate(DateTime dateTime, TimeSpan offset)
                 static void ThrowOutOfRange() => throw new ArgumentOutOfRangeException(nameof(offset), SR.Argument_UTCOutOfRange);
             }
             // make sure the Kind is set to Unspecified
-            return DateTime.UnsafeCreate(utcTicks);
+            return DateTime.CreateUnchecked(utcTicks);
         }
 
         private static DateTimeStyles ValidateStyles(DateTimeStyles styles)