reactos/include/msvcrt/float.h

   1 /*
   2  * float.h
   3  *
   4  * Constants related to floating point arithmetic.
   5  *
   6  * Also included here are some non-ANSI bits for accessing the floating
   7  * point controller.
   8  *
   9  * NOTE: GCC provides float.h, and it is probably more accurate than this,
  10  *       but it doesn't include the non-standard stuff for accessing the
  11  *       fp controller. (TODO: Move those bits elsewhere?) Thus it is
  12  *       probably not a good idea to use the GCC supplied version instead
  13  *       of this header.
  14  *
  15  * This file is part of the Mingw32 package.
  16  *
  17  * Contributors:
  18  *  Created by Colin Peters <colin@bird.fu.is.saga-u.ac.jp>
  19  *
  20  *  THIS SOFTWARE IS NOT COPYRIGHTED
  21  *
  22  *  This source code is offered for use in the public domain. You may
  23  *  use, modify or distribute it freely.
  24  *
  25  *  This code is distributed in the hope that it will be useful but
  26  *  WITHOUT ANY WARRANTY. ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
  27  *  DISCLAIMED. This includes but is not limited to warranties of
  28  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  29  *
  30  * $Revision: 1.5 $
  31  * $Author$
  32  * $Date$
  33  *
  34  */
  35
  36 #ifndef _FLOAT_H_
  37 #define _FLOAT_H_
  38
  39
  40 #define FLT_ROUNDS      1
  41 #define FLT_GUARD       1
  42 #define FLT_NORMALIZE   1
  43
  44 /*
  45  * The characteristics of float.
  46  */
  47
  48 /* The radix for floating point representation. */
  49 #define FLT_RADIX       2
  50
  51 /* Decimal digits of precision. */
  52 #define FLT_DIG         6
  53
  54 /* Smallest number such that 1+x != 1 */
  55 #define FLT_EPSILON     1.19209290e-07F
  56
  57 /* The number of base FLT_RADIX digits in the mantissa. */
  58 #define FLT_MANT_DIG    24
  59
  60 /* The maximum floating point number. */
  61 #define FLT_MAX         3.40282347e+38F
  62
  63 /* Maximum n such that FLT_RADIX^n - 1 is representable. */
  64 #define FLT_MAX_EXP     128
  65
  66 /* Maximum n such that 10^n is representable. */
  67 #define FLT_MAX_10_EXP  38
  68
  69 /* Minimum normalized floating-point number. */
  70 #define FLT_MIN         1.17549435e-38F
  71
  72 /* Minimum n such that FLT_RADIX^n is a normalized number. */
  73 #define FLT_MIN_EXP     (-125)
  74
  75 /* Minimum n such that 10^n is a normalized number. */
  76 #define FLT_MIN_10_EXP  (-37)
  77
  78
  79 /*
  80  * The characteristics of double.
  81  */
  82 #define DBL_DIG         15
  83 #define DBL_EPSILON     1.1102230246251568e-16
  84 #define DBL_MANT_DIG    53
  85 #define DBL_MAX         1.7976931348623157e+308
  86 #define DBL_MAX_EXP     1024
  87 #define DBL_MAX_10_EXP  308
  88 #define DBL_MIN         2.2250738585072014e-308
  89 #define DBL_MIN_EXP     (-1021)
  90 #define DBL_MIN_10_EXP  (-307)
  91
  92
  93 /*
  94  * The characteristics of long double.
  95  * NOTE: long double is the same as double.
  96  */
  97 #define LDBL_DIG        15
  98 #define LDBL_EPSILON    1.1102230246251568e-16L
  99 #define LDBL_MANT_DIG   53
 100 #define LDBL_MAX        1.7976931348623157e+308L
 101 #define LDBL_MAX_EXP    1024
 102 #define LDBL_MAX_10_EXP 308
 103 #define LDBL_MIN        2.2250738585072014e-308L
 104 #define LDBL_MIN_EXP    (-1021)
 105 #define LDBL_MIN_10_EXP (-307)
 106
 107
 108 /*
 109  * Functions and definitions for controlling the FPU.
 110  */
 111 #ifndef __STRICT_ANSI__
 112
 113 /* TODO: These constants are only valid for x86 machines */
 114
 115 /* Control word masks for unMask */
 116 #define _MCW_EM         0x0008001F      /* Error masks */
 117 #define _MCW_IC         0x00040000      /* Infinity */
 118 #define _MCW_RC         0x00000300      /* Rounding */
 119 #define _MCW_PC         0x00030000      /* Precision */
 120
 121 /* Control word values for unNew (use with related unMask above) */
 122 #define _EM_INVALID     0x00000010
 123 #define _EM_DENORMAL    0x00080000
 124 #define _EM_ZERODIVIDE  0x00000008
 125 #define _EM_OVERFLOW    0x00000004
 126 #define _EM_UNDERFLOW   0x00000002
 127 #define _EM_INEXACT     0x00000001
 128 #define _IC_AFFINE      0x00040000
 129 #define _IC_PROJECTIVE  0x00000000
 130 #define _RC_CHOP        0x00000300
 131 #define _RC_UP          0x00000200
 132 #define _RC_DOWN        0x00000100
 133 #define _RC_NEAR        0x00000000
 134 #define _PC_24          0x00020000
 135 #define _PC_53          0x00010000
 136 #define _PC_64          0x00000000
 137
 138 /* Return values for fpclass. */
 139 #define _FPCLASS_SNAN   0x0001  /* Signaling "Not a Number" */
 140 #define _FPCLASS_QNAN   0x0002  /* Quiet "Not a Number" */
 141 #define _FPCLASS_NINF   0x0004  /* Negative Infinity */
 142 #define _FPCLASS_NN     0x0008  /* Negative Normal */
 143 #define _FPCLASS_ND     0x0010  /* Negative Denormal */
 144 #define _FPCLASS_NZ     0x0020  /* Negative Zero */
 145 #define _FPCLASS_PZ     0x0040  /* Positive Zero */
 146 #define _FPCLASS_PD     0x0080  /* Positive Denormal */
 147 #define _FPCLASS_PN     0x0100  /* Positive Normal */
 148 #define _FPCLASS_PINF   0x0200  /* Positive Infinity */
 149
 150
 151 #ifdef  __cplusplus
 152 extern "C" {
 153 #endif
 154
 155
 156 /* Set the FPU control word as cw = (cw & ~unMask) | (unNew & unMask),
 157  * i.e. change the bits in unMask to have the values they have in unNew,
 158  * leaving other bits unchanged. */
 159 unsigned int    _controlfp(unsigned int unNew, unsigned int unMask);
 160 unsigned int    _control87(unsigned int unNew, unsigned int unMask);
 161
 162
 163 unsigned int    _clearfp(void);        /* Clear the FPU status word */
 164 unsigned int    _statusfp(void);       /* Report the FPU status word */
 165 #define         _clear87        _clearfp
 166 #define         _status87       _statusfp
 167
 168
 169 /*
 170    MSVCRT.dll _fpreset initializes the control register to 0x27f,
 171    the status register to zero and the tag word to 0FFFFh.
 172    This differs from asm instruction finit/fninit which set control
 173    word to 0x37f (64 bit mantissa precison rather than 53 bit).
 174    By default, the mingw version of _fpreset sets fp control as
 175    per fninit. To use the MSVCRT.dll _fpreset, include CRT_fp8.o when
 176    building your application.
 177 */
 178 void _fpreset(void);        /* Reset the FPU */
 179
 180 /* Global 'variable' for the current floating point error code. */
 181 int*  __fpecode(void);
 182 #define _fpecode  (*(__fpecode()))
 183
 184 /*
 185  * IEEE recommended functions.  MS puts them in float.h
 186  * but they really belong in math.h.
 187  */
 188
 189 double  _chgsign        (double);
 190 double  _copysign       (double, double);
 191 double  _logb           (double);
 192 double  _nextafter      (double, double);
 193 double  _scalb          (double, long);
 194
 195 int     _finite         (double);
 196 int     _fpclass        (double);
 197 int     _isnan          (double);
 198
 199 int     _isinf          (double); /* not exported */
 200 int     _isnanl         (long double); /* not exported */
 201 int     _isinfl         (long double); /* not exported */
 202
 203 #define isnan(x)        _isnan(x)
 204 #define isinf(x)        _isinf(x)
 205
 206
 207 #ifdef  __cplusplus
 208 }
 209 #endif
 210
 211 #endif  /* Not __STRICT_ANSI__ */
 212
 213 #endif /* _FLOAT_H_ */
 214