include/crt/fenv.h

   1 /**
   2  * This file has no copyright assigned and is placed in the Public Domain.
   3  * This file is part of the w64 mingw-runtime package.
   4  * No warranty is given; refer to the file DISCLAIMER within this package.
   5  */
   6 #ifndef _FENV_H_
   7 #define _FENV_H_
   8
   9 /* FPU status word exception flags */
  10 #define FE_INVALID      0x01
  11 #define FE_DENORMAL     0x02
  12 #define FE_DIVBYZERO    0x04
  13 #define FE_OVERFLOW     0x08
  14 #define FE_UNDERFLOW    0x10
  15 #define FE_INEXACT      0x20
  16 #define FE_ALL_EXCEPT (FE_INVALID | FE_DENORMAL | FE_DIVBYZERO \
  17                        | FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)
  18
  19 /* FPU control word rounding flags */
  20 #define FE_TONEAREST    0x0000
  21 #define FE_DOWNWARD     0x0400
  22 #define FE_UPWARD       0x0800
  23 #define FE_TOWARDZERO   0x0c00
  24
  25 /* The MXCSR exception flags are the same as the
  26    FE flags. */
  27 #define __MXCSR_EXCEPT_FLAG_SHIFT 0
  28
  29 /* How much to shift FE status word exception flags
  30    to get MXCSR rounding flags,  */
  31 #define __MXCSR_ROUND_FLAG_SHIFT 3
  32
  33 #ifndef RC_INVOKED
  34 /*
  35   For now, support only for the basic abstraction of flags that are
  36   either set or clear. fexcept_t could be  structure that holds more
  37   info about the fp environment.
  38 */
  39 typedef unsigned short fexcept_t;
  40
  41 /* This 32-byte struct represents the entire floating point
  42    environment as stored by fnstenv or fstenv, augmented by
  43    the  contents of the MXCSR register, as stored by stmxcsr
  44    (if CPU supports it). */
  45 typedef struct
  46 {
  47   unsigned short __control_word;
  48   unsigned short __unused0;
  49   unsigned short __status_word;
  50   unsigned short __unused1;
  51   unsigned short __tag_word;
  52   unsigned short __unused2;
  53   unsigned int   __ip_offset;    /* instruction pointer offset */
  54   unsigned short __ip_selector;
  55   unsigned short __opcode;
  56   unsigned int   __data_offset;
  57   unsigned short __data_selector;
  58   unsigned short __unused3;
  59   unsigned int   __mxcsr; /* contents of the MXCSR register  */
  60 } fenv_t;
  61
  62
  63 /*The C99 standard (7.6.9) allows us to define implementation-specific macros for
  64   different fp environments */
  65
  66 /* The default Intel x87 floating point environment (64-bit mantissa) */
  67 #define FE_PC64_ENV ((const fenv_t *)-1)
  68
  69 /* The floating point environment set by MSVCRT _fpreset (53-bit mantissa) */
  70 #define FE_PC53_ENV ((const fenv_t *)-2)
  71
  72 /* The FE_DFL_ENV macro is required by standard.
  73   fesetenv will use the environment set at app startup.*/
  74 #define FE_DFL_ENV ((const fenv_t *) 0)
  75
  76 #ifdef __cplusplus
  77 extern "C" {
  78 #endif
  79
  80 /*TODO: Some of these could be inlined */
  81 /* 7.6.2 Exception */
  82
  83 extern int __cdecl feclearexcept (int);
  84 extern int __cdecl fegetexceptflag (fexcept_t * flagp, int excepts);
  85 extern int __cdecl feraiseexcept (int excepts );
  86 extern int __cdecl fesetexceptflag (const fexcept_t *, int);
  87 extern int __cdecl fetestexcept (int excepts);
  88
  89 /* 7.6.3 Rounding */
  90
  91 extern int __cdecl fegetround (void);
  92 extern int __cdecl fesetround (int mode);
  93
  94 /* 7.6.4 Environment */
  95
  96 extern int __cdecl fegetenv(fenv_t * envp);
  97 extern int __cdecl fesetenv(const fenv_t * );
  98 extern int __cdecl feupdateenv(const fenv_t *);
  99 extern int __cdecl feholdexcept(fenv_t *);
 100
 101 #ifdef __cplusplus
 102 }
 103 #endif
 104 #endif  /* Not RC_INVOKED */
 105
 106 #endif /* ndef _FENV_H */