reactos/include/crtdll/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  *  DISCLAMED. This includes but is not limited to warranties of
  28  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  29  *
  30  * $Revision: 1.5 $
  31  * $Author: ariadne $
  32  * $Date: 1999/04/23 18:43:00 $
  33  *
  34  */
  35
  36 #ifndef _FLOAT_H_
  37 #define _FLOAT_H_
  38
  39 #ifdef  __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 #define FLT_ROUNDS      1
  44 #define FLT_GUARD       1
  45 #define FLT_NORMALIZE   1
  46
  47 /*
  48  * The characteristics of float.
  49  */
  50
  51 /* The radix for floating point representation. */
  52 #define FLT_RADIX       2
  53
  54 /* Decimal digits of precision. */
  55 #define FLT_DIG         6
  56
  57 /* Smallest number such that 1+x != 1 */
  58 #define FLT_EPSILON     1.19209290e-07F
  59
  60 /* The number of base FLT_RADIX digits in the mantissa. */
  61 #define FLT_MANT_DIG    24
  62
  63 /* The maximum floating point number. */
  64 #define FLT_MAX         3.40282347e+38F
  65
  66 /* Maximum n such that FLT_RADIX^n - 1 is representable. */
  67 #define FLT_MAX_EXP     128
  68
  69 /* Maximum n such that 10^n is representable. */
  70 #define FLT_MAX_10_EXP  38
  71
  72 /* Minimum normalized floating-point number. */
  73 #define FLT_MIN         1.17549435e-38F
  74
  75 /* Minimum n such that FLT_RADIX^n is a normalized number. */
  76 #define FLT_MIN_EXP     (-125)
  77
  78 /* Minimum n such that 10^n is a normalized number. */
  79 #define FLT_MIN_10_EXP  (-37)
  80
  81
  82 /*
  83  * The characteristics of double.
  84  */
  85 #define DBL_DIG         15
  86 #define DBL_EPSILON     1.1102230246251568e-16
  87 #define DBL_MANT_DIG    53
  88 #define DBL_MAX         1.7976931348623157e+308
  89 #define DBL_MAX_EXP     1024
  90 #define DBL_MAX_10_EXP  308
  91 #define DBL_MIN         2.2250738585072014e-308
  92 #define DBL_MIN_EXP     (-1021)
  93 #define DBL_MIN_10_EXP  (-307)
  94
  95
  96 /*
  97  * The characteristics of long double.
  98  * NOTE: long double is the same as double.
  99  */
 100 #define LDBL_DIG        15
 101 #define LDBL_EPSILON    1.1102230246251568e-16L
 102 #define LDBL_MANT_DIG   53
 103 #define LDBL_MAX        1.7976931348623157e+308L
 104 #define LDBL_MAX_EXP    1024
 105 #define LDBL_MAX_10_EXP 308
 106 #define LDBL_MIN        2.2250738585072014e-308L
 107 #define LDBL_MIN_EXP    (-1021)
 108 #define LDBL_MIN_10_EXP (-307)
 109
 110
 111 /*
 112  * Functions and definitions for controlling the FPU.
 113  */
 114 #ifndef __STRICT_ANSI__
 115
 116 /* TODO: These constants are only valid for x86 machines */
 117
 118 /* Control word masks for unMask */
 119 #define _MCW_EM         0x0008001F      /* Error masks */
 120 #define _MCW_IC         0x00040000      /* Infinity */
 121 #define _MCW_RC         0x00000300      /* Rounding */
 122 #define _MCW_PC         0x00030000      /* Precision */
 123
 124 /* Control word values for unNew (use with related unMask above) */
 125 #define _EM_INVALID     0x00000010
 126 #define _EM_DENORMAL    0x00080000
 127 #define _EM_ZERODIVIDE  0x00000008
 128 #define _EM_OVERFLOW    0x00000004
 129 #define _EM_UNDERFLOW   0x00000002
 130 #define _EM_INEXACT     0x00000001
 131 #define _IC_AFFINE      0x00040000
 132 #define _IC_PROJECTIVE  0x00000000
 133 #define _RC_CHOP        0x00000300
 134 #define _RC_UP          0x00000200
 135 #define _RC_DOWN        0x00000100
 136 #define _RC_NEAR        0x00000000
 137 #define _PC_24          0x00020000
 138 #define _PC_53          0x00010000
 139 #define _PC_64          0x00000000
 140
 141
 142 /* Set the FPU control word as cw = (cw & ~unMask) | (unNew & unMask),
 143  * i.e. change the bits in unMask to have the values they have in unNew,
 144  * leaving other bits unchanged. */
 145 unsigned int    _controlfp (unsigned int unNew, unsigned int unMask);
 146 unsigned int    _control87 (unsigned int unNew, unsigned int unMask);
 147
 148
 149 unsigned int    _clearfp (void);        /* Clear the FPU status word */
 150 unsigned int    _statusfp (void);       /* Report the FPU status word */
 151 #define         _clear87        _clearfp
 152 #define         _status87       _statusfp
 153
 154 void            _fpreset (void);        /* Reset the FPU */
 155
 156 /* Global 'variable' for the current floating point error code. */
 157 int *   __fpecode(void);
 158 #define _fpecode        (*(__fpecode()))
 159
 160 /*
 161  * IEEE recommended functions
 162  */
 163
 164 double  _chgsign        (double x);
 165 double  _copysign       (double dTo, double dFrom);
 166 double  _logb           (double x);
 167 double  _nextafter      (double x, double y);
 168 double  _scalb          (double x, long n);
 169
 170 /* Return values for fpclass. */
 171 #define _FPCLASS_SNAN   0x0001  /* Signaling "Not a Number" */
 172 #define _FPCLASS_QNAN   0x0002  /* Quiet "Not a Number" */
 173 #define _FPCLASS_NINF   0x0004  /* Negative Infinity */
 174 #define _FPCLASS_NN     0x0008  /* Negative Normal */
 175 #define _FPCLASS_ND     0x0010  /* Negative Denormal */
 176 #define _FPCLASS_NZ     0x0020  /* Negative Zero */
 177 #define _FPCLASS_PZ     0x0040  /* Positive Zero */
 178 #define _FPCLASS_PD     0x0080  /* Positive Denormal */
 179 #define _FPCLASS_PN     0x0100  /* Positive Normal */
 180 #define _FPCLASS_PINF   0x0200  /* Positive Infinity */
 181
 182 int     _finite         (double x);
 183 int     _fpclass        (double x);
 184 int     _isnan          (double x);
 185 int     _isinf          (double x); // not exported
 186
 187 int     _isnanl         (long double x); // not exported
 188 int     _isinfl         (long double x); // not exported
 189
 190 #define isnan(x)        _isnan(x)
 191 #define isinf(x)        _isinf(x)
 192
 193 #endif  /* Not __STRICT_ANSI__ */
 194
 195 #ifdef  __cplusplus
 196 }
 197 #endif
 198
 199 #endif /* _FLOAT_H_ */