source: Daodan/MinGW/include/float.h@ 1126

#ifndef _MINGW_FLOAT_H_
/*
 * float.h
 *
 * This file has no copyright assigned and is placed in the Public Domain.
 * This file is a part of the mingw-runtime package.
 * No warranty is given; refer to the file DISCLAIMER within the package.
 *
 * Constants related to floating point arithmetic.
 *
 * Also included here are some non-ANSI bits for accessing the floating
 * point controller.
 *
 */
#define _MINGW_FLOAT_H_
/*
 * NOTE:
 *
 * GCC provides float.h, but it doesn't include the non-standard stuff for
 * accessing the fp controller.  We parse the GCC-supplied header, for its
 * standard content, and then define the MS-specific extensions here.
 *
 * In a MinGW standard Win32 hosted environment, this should be the float.h
 * found by a system include path search, but this can't be guaranteed; for
 * a cross-compiler setup, the GCC-supplied header, which is guarded by the
 * _FLOAT_H___ macro, may be found first, thus...
 *
 */
#if !defined(_FLOAT_H___) && !defined(__FLOAT_H)

 /*
  * ...when we didn't find the GCC-supplied header first, we want to pull
  * it in now; include_next should achieve this, (and we must rely on the
  * GCC header maintainers to extend us the same courtesy, to get this one
  * pulled in, when the GCC-supplied header is found first).
  *
  */
# include_next <float.h>
#endif

/* All the headers include this file. */
#include <_mingw.h>

/*
 * Functions and definitions for controlling the FPU.
 */
#ifndef __STRICT_ANSI__

/* TODO: These constants are only valid for x86 machines */

/* Control word masks for unMask */
#define _MCW_EM         0x0008001F      /* Error masks */
#define _MCW_IC         0x00040000      /* Infinity */
#define _MCW_RC         0x00000300      /* Rounding */
#define _MCW_PC         0x00030000      /* Precision */

/* Control word values for unNew (use with related unMask above) */
#define _EM_INVALID     0x00000010
#define _EM_DENORMAL    0x00080000
#define _EM_ZERODIVIDE  0x00000008
#define _EM_OVERFLOW    0x00000004
#define _EM_UNDERFLOW   0x00000002
#define _EM_INEXACT     0x00000001
#define _IC_AFFINE      0x00040000
#define _IC_PROJECTIVE  0x00000000
#define _RC_CHOP        0x00000300
#define _RC_UP          0x00000200
#define _RC_DOWN        0x00000100
#define _RC_NEAR        0x00000000
#define _PC_24          0x00020000
#define _PC_53          0x00010000
#define _PC_64          0x00000000

/* These are also defined in Mingw math.h, needed to work around
   GCC build issues.  */
/* Return values for fpclass. */
#ifndef __MINGW_FPCLASS_DEFINED
#define __MINGW_FPCLASS_DEFINED 1
#define _FPCLASS_SNAN   0x0001  /* Signaling "Not a Number" */
#define _FPCLASS_QNAN   0x0002  /* Quiet "Not a Number" */
#define _FPCLASS_NINF   0x0004  /* Negative Infinity */
#define _FPCLASS_NN     0x0008  /* Negative Normal */
#define _FPCLASS_ND     0x0010  /* Negative Denormal */
#define _FPCLASS_NZ     0x0020  /* Negative Zero */
#define _FPCLASS_PZ     0x0040  /* Positive Zero */
#define _FPCLASS_PD     0x0080  /* Positive Denormal */
#define _FPCLASS_PN     0x0100  /* Positive Normal */
#define _FPCLASS_PINF   0x0200  /* Positive Infinity */
#endif /* __MINGW_FPCLASS_DEFINED */

/* invalid subconditions (_SW_INVALID also set) */
#define _SW_UNEMULATED          0x0040  /* unemulated instruction */
#define _SW_SQRTNEG             0x0080  /* square root of a neg number */
#define _SW_STACKOVERFLOW       0x0200  /* FP stack overflow */
#define _SW_STACKUNDERFLOW      0x0400  /* FP stack underflow */

/*  Floating point error signals and return codes */
#define _FPE_INVALID            0x81
#define _FPE_DENORMAL           0x82
#define _FPE_ZERODIVIDE         0x83
#define _FPE_OVERFLOW           0x84
#define _FPE_UNDERFLOW          0x85
#define _FPE_INEXACT            0x86
#define _FPE_UNEMULATED         0x87
#define _FPE_SQRTNEG            0x88
#define _FPE_STACKOVERFLOW      0x8a
#define _FPE_STACKUNDERFLOW     0x8b
#define _FPE_EXPLICITGEN        0x8c    /* raise( SIGFPE ); */

#ifndef RC_INVOKED

#ifdef  __cplusplus
extern "C" {
#endif

/* Set the FPU control word as cw = (cw & ~unMask) | (unNew & unMask),
 * i.e. change the bits in unMask to have the values they have in unNew,
 * leaving other bits unchanged. */
_CRTIMP unsigned int __cdecl __MINGW_NOTHROW _controlfp (unsigned int unNew, unsigned int unMask);
_CRTIMP unsigned int __cdecl __MINGW_NOTHROW _control87 (unsigned int unNew, unsigned int unMask);


_CRTIMP unsigned int __cdecl __MINGW_NOTHROW _clearfp (void);   /* Clear the FPU status word */
_CRTIMP unsigned int __cdecl __MINGW_NOTHROW _statusfp (void);  /* Report the FPU status word */
#define         _clear87        _clearfp
#define         _status87       _statusfp


/*
   MSVCRT.dll _fpreset initializes the control register to 0x27f,
   the status register to zero and the tag word to 0FFFFh.
   This differs from asm instruction finit/fninit which set control
   word to 0x37f (64 bit mantissa precison rather than 53 bit).
   By default, the mingw version of _fpreset sets fp control as
   per fninit. To use the MSVCRT.dll _fpreset, include CRT_fp8.o when
   building your application.
*/
void __cdecl __MINGW_NOTHROW _fpreset (void);
void __cdecl __MINGW_NOTHROW fpreset (void);

/* Global 'variable' for the current floating point error code. */
_CRTIMP int * __cdecl __MINGW_NOTHROW __fpecode(void);
#define _fpecode        (*(__fpecode()))

/*
 * IEEE recommended functions.  MS puts them in float.h
 * but they really belong in math.h.
 */

_CRTIMP double __cdecl __MINGW_NOTHROW _chgsign (double);
_CRTIMP double __cdecl __MINGW_NOTHROW _copysign (double, double);
_CRTIMP double __cdecl __MINGW_NOTHROW _logb (double);
_CRTIMP double __cdecl __MINGW_NOTHROW _nextafter (double, double);
_CRTIMP double __cdecl __MINGW_NOTHROW _scalb (double, long);

_CRTIMP int __cdecl __MINGW_NOTHROW _finite (double);
_CRTIMP int __cdecl __MINGW_NOTHROW _fpclass (double);
_CRTIMP int __cdecl __MINGW_NOTHROW _isnan (double);

#ifdef  __cplusplus
}
#endif

#endif  /* Not RC_INVOKED */

#endif  /* Not __STRICT_ANSI__ */

#endif /* _MINGW_FLOAT_H_ */