netcore/System.Private.CoreLib/shared/System/Double.cs

   1 // Licensed to the .NET Foundation under one or more agreements.
   2 // The .NET Foundation licenses this file to you under the MIT license.
   3 // See the LICENSE file in the project root for more information.
   4
   5 /*============================================================
   6 **
   7 **
   8 **
   9 ** Purpose: A representation of an IEEE double precision
  10 **          floating point number.
  11 **
  12 **
  13 ===========================================================*/
  14
  15 using System.Globalization;
  16 using System.Runtime.CompilerServices;
  17 using System.Runtime.InteropServices;
  18 using System.Runtime.Versioning;
  19
  20 using Internal.Runtime.CompilerServices;
  21
  22 namespace System
  23 {
  24     [Serializable]
  25     [StructLayout(LayoutKind.Sequential)]
  26     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
  27     public readonly struct Double : IComparable, IConvertible, IFormattable, IComparable<double>, IEquatable<double>, ISpanFormattable
  28     {
  29         private readonly double m_value; // Do not rename (binary serialization)
  30
  31         //
  32         // Public Constants
  33         //
  34         public const double MinValue = -1.7976931348623157E+308;
  35         public const double MaxValue = 1.7976931348623157E+308;
  36
  37         // Note Epsilon should be a double whose hex representation is 0x1
  38         // on little endian machines.
  39         public const double Epsilon = 4.9406564584124654E-324;
  40         public const double NegativeInfinity = (double)-1.0 / (double)(0.0);
  41         public const double PositiveInfinity = (double)1.0 / (double)(0.0);
  42         public const double NaN = (double)0.0 / (double)0.0;
  43
  44         // We use this explicit definition to avoid the confusion between 0.0 and -0.0.
  45         internal const double NegativeZero = -0.0;
  46
  47         //
  48         // Constants for manipulating the private bit-representation
  49         //
  50
  51         internal const ulong SignMask = 0x8000_0000_0000_0000;
  52         internal const int SignShift = 63;
  53         internal const int ShiftedSignMask = (int)(SignMask >> SignShift);
  54
  55         internal const ulong ExponentMask = 0x7FF0_0000_0000_0000;
  56         internal const int ExponentShift = 52;
  57         internal const int ShiftedExponentMask = (int)(ExponentMask >> ExponentShift);
  58
  59         internal const ulong SignificandMask = 0x000F_FFFF_FFFF_FFFF;
  60
  61         internal const byte MinSign = 0;
  62         internal const byte MaxSign = 1;
  63
  64         internal const ushort MinExponent = 0x0000;
  65         internal const ushort MaxExponent = 0x07FF;
  66
  67         internal const ulong MinSignificand = 0x0000_0000_0000_0000;
  68         internal const ulong MaxSignificand = 0x000F_FFFF_FFFF_FFFF;
  69
  70         /// <summary>Determines whether the specified value is finite (zero, subnormal, or normal).</summary>
  71         [NonVersionable]
  72         [MethodImpl(MethodImplOptions.AggressiveInlining)]
  73         public static unsafe bool IsFinite(double d)
  74         {
  75             long bits = BitConverter.DoubleToInt64Bits(d);
  76             return (bits & 0x7FFFFFFFFFFFFFFF) < 0x7FF0000000000000;
  77         }
  78
  79         /// <summary>Determines whether the specified value is infinite.</summary>
  80         [NonVersionable]
  81         [MethodImpl(MethodImplOptions.AggressiveInlining)]
  82         public static unsafe bool IsInfinity(double d)
  83         {
  84             long bits = BitConverter.DoubleToInt64Bits(d);
  85             return (bits & 0x7FFFFFFFFFFFFFFF) == 0x7FF0000000000000;
  86         }
  87
  88         /// <summary>Determines whether the specified value is NaN.</summary>
  89         [NonVersionable]
  90         [MethodImpl(MethodImplOptions.AggressiveInlining)]
  91         public static unsafe bool IsNaN(double d)
  92         {
  93             long bits = BitConverter.DoubleToInt64Bits(d);
  94             return (bits & 0x7FFFFFFFFFFFFFFF) > 0x7FF0000000000000;
  95         }
  96
  97         /// <summary>Determines whether the specified value is negative.</summary>
  98         [NonVersionable]
  99         [MethodImpl(MethodImplOptions.AggressiveInlining)]
 100         public static unsafe bool IsNegative(double d)
 101         {
 102             return BitConverter.DoubleToInt64Bits(d) < 0;
 103         }
 104
 105         /// <summary>Determines whether the specified value is negative infinity.</summary>
 106         [NonVersionable]
 107         [MethodImpl(MethodImplOptions.AggressiveInlining)]
 108         public static bool IsNegativeInfinity(double d)
 109         {
 110             return d == double.NegativeInfinity;
 111         }
 112
 113         /// <summary>Determines whether the specified value is normal.</summary>
 114         [NonVersionable]
 115         // This is probably not worth inlining, it has branches and should be rarely called
 116         public static unsafe bool IsNormal(double d)
 117         {
 118             long bits = BitConverter.DoubleToInt64Bits(d);
 119             bits &= 0x7FFFFFFFFFFFFFFF;
 120             return (bits < 0x7FF0000000000000) && (bits != 0) && ((bits & 0x7FF0000000000000) != 0);
 121         }
 122
 123         /// <summary>Determines whether the specified value is positive infinity.</summary>
 124         [NonVersionable]
 125         [MethodImpl(MethodImplOptions.AggressiveInlining)]
 126         public static bool IsPositiveInfinity(double d)
 127         {
 128             return d == double.PositiveInfinity;
 129         }
 130
 131         /// <summary>Determines whether the specified value is subnormal.</summary>
 132         [NonVersionable]
 133         // This is probably not worth inlining, it has branches and should be rarely called
 134         public static unsafe bool IsSubnormal(double d)
 135         {
 136             long bits = BitConverter.DoubleToInt64Bits(d);
 137             bits &= 0x7FFFFFFFFFFFFFFF;
 138             return (bits < 0x7FF0000000000000) && (bits != 0) && ((bits & 0x7FF0000000000000) == 0);
 139         }
 140
 141         internal static int ExtractExponentFromBits(ulong bits)
 142         {
 143             return (int)(bits >> ExponentShift) & ShiftedExponentMask;
 144         }
 145
 146         internal static ulong ExtractSignificandFromBits(ulong bits)
 147         {
 148             return bits & SignificandMask;
 149         }
 150
 151         // Compares this object to another object, returning an instance of System.Relation.
 152         // Null is considered less than any instance.
 153         //
 154         // If object is not of type Double, this method throws an ArgumentException.
 155         //
 156         // Returns a value less than zero if this  object
 157         //
 158         public int CompareTo(object? value)
 159         {
 160             if (value == null)
 161             {
 162                 return 1;
 163             }
 164
 165             if (value is double d)
 166             {
 167                 if (m_value < d) return -1;
 168                 if (m_value > d) return 1;
 169                 if (m_value == d) return 0;
 170
 171                 // At least one of the values is NaN.
 172                 if (IsNaN(m_value))
 173                     return IsNaN(d) ? 0 : -1;
 174                 else
 175                     return 1;
 176             }
 177
 178             throw new ArgumentException(SR.Arg_MustBeDouble);
 179         }
 180
 181         public int CompareTo(double value)
 182         {
 183             if (m_value < value) return -1;
 184             if (m_value > value) return 1;
 185             if (m_value == value) return 0;
 186
 187             // At least one of the values is NaN.
 188             if (IsNaN(m_value))
 189                 return IsNaN(value) ? 0 : -1;
 190             else
 191                 return 1;
 192         }
 193
 194         // True if obj is another Double with the same value as the current instance.  This is
 195         // a method of object equality, that only returns true if obj is also a double.
 196         public override bool Equals(object? obj)
 197         {
 198             if (!(obj is double))
 199             {
 200                 return false;
 201             }
 202             double temp = ((double)obj).m_value;
 203             // This code below is written this way for performance reasons i.e the != and == check is intentional.
 204             if (temp == m_value)
 205             {
 206                 return true;
 207             }
 208             return IsNaN(temp) && IsNaN(m_value);
 209         }
 210
 211         [NonVersionable]
 212         public static bool operator ==(double left, double right) => left == right;
 213
 214         [NonVersionable]
 215         public static bool operator !=(double left, double right) => left != right;
 216
 217         [NonVersionable]
 218         public static bool operator <(double left, double right) => left < right;
 219
 220         [NonVersionable]
 221         public static bool operator >(double left, double right) => left > right;
 222
 223         [NonVersionable]
 224         public static bool operator <=(double left, double right) => left <= right;
 225
 226         [NonVersionable]
 227         public static bool operator >=(double left, double right) => left >= right;
 228
 229         public bool Equals(double obj)
 230         {
 231             if (obj == m_value)
 232             {
 233                 return true;
 234             }
 235             return IsNaN(obj) && IsNaN(m_value);
 236         }
 237
 238         // The hashcode for a double is the absolute value of the integer representation
 239         // of that double.
 240         [MethodImpl(MethodImplOptions.AggressiveInlining)] // 64-bit constants make the IL unusually large that makes the inliner to reject the method
 241         public override int GetHashCode()
 242         {
 243             long bits = Unsafe.As<double, long>(ref Unsafe.AsRef(in m_value));
 244
 245             // Optimized check for IsNan() || IsZero()
 246             if (((bits - 1) & 0x7FFFFFFFFFFFFFFF) >= 0x7FF0000000000000)
 247             {
 248                 // Ensure that all NaNs and both zeros have the same hash code
 249                 bits &= 0x7FF0000000000000;
 250             }
 251
 252             return unchecked((int)bits) ^ ((int)(bits >> 32));
 253         }
 254
 255         public override string ToString()
 256         {
 257             return Number.FormatDouble(m_value, null, NumberFormatInfo.CurrentInfo);
 258         }
 259
 260         public string ToString(string? format)
 261         {
 262             return Number.FormatDouble(m_value, format, NumberFormatInfo.CurrentInfo);
 263         }
 264
 265         public string ToString(IFormatProvider? provider)
 266         {
 267             return Number.FormatDouble(m_value, null, NumberFormatInfo.GetInstance(provider));
 268         }
 269
 270         public string ToString(string? format, IFormatProvider? provider)
 271         {
 272             return Number.FormatDouble(m_value, format, NumberFormatInfo.GetInstance(provider));
 273         }
 274
 275         public bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format = default, IFormatProvider? provider = null)
 276         {
 277             return Number.TryFormatDouble(m_value, format, NumberFormatInfo.GetInstance(provider), destination, out charsWritten);
 278         }
 279
 280         public static double Parse(string s)
 281         {
 282             if (s == null) ThrowHelper.ThrowArgumentNullException(ExceptionArgument.s);
 283             return Number.ParseDouble(s, NumberStyles.Float | NumberStyles.AllowThousands, NumberFormatInfo.CurrentInfo);
 284         }
 285
 286         public static double Parse(string s, NumberStyles style)
 287         {
 288             NumberFormatInfo.ValidateParseStyleFloatingPoint(style);
 289             if (s == null) ThrowHelper.ThrowArgumentNullException(ExceptionArgument.s);
 290             return Number.ParseDouble(s, style, NumberFormatInfo.CurrentInfo);
 291         }
 292
 293         public static double Parse(string s, IFormatProvider? provider)
 294         {
 295             if (s == null) ThrowHelper.ThrowArgumentNullException(ExceptionArgument.s);
 296             return Number.ParseDouble(s, NumberStyles.Float | NumberStyles.AllowThousands, NumberFormatInfo.GetInstance(provider));
 297         }
 298
 299         public static double Parse(string s, NumberStyles style, IFormatProvider? provider)
 300         {
 301             NumberFormatInfo.ValidateParseStyleFloatingPoint(style);
 302             if (s == null) ThrowHelper.ThrowArgumentNullException(ExceptionArgument.s);
 303             return Number.ParseDouble(s, style, NumberFormatInfo.GetInstance(provider));
 304         }
 305
 306         // Parses a double from a String in the given style.  If
 307         // a NumberFormatInfo isn't specified, the current culture's
 308         // NumberFormatInfo is assumed.
 309         //
 310         // This method will not throw an OverflowException, but will return
 311         // PositiveInfinity or NegativeInfinity for a number that is too
 312         // large or too small.
 313
 314         public static double Parse(ReadOnlySpan<char> s, NumberStyles style = NumberStyles.Float | NumberStyles.AllowThousands, IFormatProvider? provider = null)
 315         {
 316             NumberFormatInfo.ValidateParseStyleFloatingPoint(style);
 317             return Number.ParseDouble(s, style, NumberFormatInfo.GetInstance(provider));
 318         }
 319
 320         public static bool TryParse(string? s, out double result)
 321         {
 322             if (s == null)
 323             {
 324                 result = 0;
 325                 return false;
 326             }
 327
 328             return TryParse((ReadOnlySpan<char>)s, NumberStyles.Float | NumberStyles.AllowThousands, NumberFormatInfo.CurrentInfo, out result);
 329         }
 330
 331         public static bool TryParse(ReadOnlySpan<char> s, out double result)
 332         {
 333             return TryParse(s, NumberStyles.Float | NumberStyles.AllowThousands, NumberFormatInfo.CurrentInfo, out result);
 334         }
 335
 336         public static bool TryParse(string? s, NumberStyles style, IFormatProvider? provider, out double result)
 337         {
 338             NumberFormatInfo.ValidateParseStyleFloatingPoint(style);
 339
 340             if (s == null)
 341             {
 342                 result = 0;
 343                 return false;
 344             }
 345
 346             return TryParse((ReadOnlySpan<char>)s, style, NumberFormatInfo.GetInstance(provider), out result);
 347         }
 348
 349         public static bool TryParse(ReadOnlySpan<char> s, NumberStyles style, IFormatProvider? provider, out double result)
 350         {
 351             NumberFormatInfo.ValidateParseStyleFloatingPoint(style);
 352             return TryParse(s, style, NumberFormatInfo.GetInstance(provider), out result);
 353         }
 354
 355         private static bool TryParse(ReadOnlySpan<char> s, NumberStyles style, NumberFormatInfo info, out double result)
 356         {
 357             return Number.TryParseDouble(s, style, info, out result);
 358         }
 359
 360         //
 361         // IConvertible implementation
 362         //
 363
 364         public TypeCode GetTypeCode()
 365         {
 366             return TypeCode.Double;
 367         }
 368
 369         bool IConvertible.ToBoolean(IFormatProvider? provider)
 370         {
 371             return Convert.ToBoolean(m_value);
 372         }
 373
 374         char IConvertible.ToChar(IFormatProvider? provider)
 375         {
 376             throw new InvalidCastException(SR.Format(SR.InvalidCast_FromTo, "Double", "Char"));
 377         }
 378
 379         sbyte IConvertible.ToSByte(IFormatProvider? provider)
 380         {
 381             return Convert.ToSByte(m_value);
 382         }
 383
 384         byte IConvertible.ToByte(IFormatProvider? provider)
 385         {
 386             return Convert.ToByte(m_value);
 387         }
 388
 389         short IConvertible.ToInt16(IFormatProvider? provider)
 390         {
 391             return Convert.ToInt16(m_value);
 392         }
 393
 394         ushort IConvertible.ToUInt16(IFormatProvider? provider)
 395         {
 396             return Convert.ToUInt16(m_value);
 397         }
 398
 399         int IConvertible.ToInt32(IFormatProvider? provider)
 400         {
 401             return Convert.ToInt32(m_value);
 402         }
 403
 404         uint IConvertible.ToUInt32(IFormatProvider? provider)
 405         {
 406             return Convert.ToUInt32(m_value);
 407         }
 408
 409         long IConvertible.ToInt64(IFormatProvider? provider)
 410         {
 411             return Convert.ToInt64(m_value);
 412         }
 413
 414         ulong IConvertible.ToUInt64(IFormatProvider? provider)
 415         {
 416             return Convert.ToUInt64(m_value);
 417         }
 418
 419         float IConvertible.ToSingle(IFormatProvider? provider)
 420         {
 421             return Convert.ToSingle(m_value);
 422         }
 423
 424         double IConvertible.ToDouble(IFormatProvider? provider)
 425         {
 426             return m_value;
 427         }
 428
 429         decimal IConvertible.ToDecimal(IFormatProvider? provider)
 430         {
 431             return Convert.ToDecimal(m_value);
 432         }
 433
 434         DateTime IConvertible.ToDateTime(IFormatProvider? provider)
 435         {
 436             throw new InvalidCastException(SR.Format(SR.InvalidCast_FromTo, "Double", "DateTime"));
 437         }
 438
 439         object IConvertible.ToType(Type type, IFormatProvider? provider)
 440         {
 441             return Convert.DefaultToType((IConvertible)this, type, provider);
 442         }
 443     }
 444 }