math/fenv.h

   1 /* Copyright (C) 1997, 1999, 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  * ISO C99 7.6: Floating-point environment      <fenv.h>
  21  */
  22
  23 #ifndef _FENV_H
  24 #define _FENV_H 1
  25
  26 #include <features.h>
  27
  28 /* Get the architecture dependend definitions.  The following definitions
  29    are expected to be done:
  30
  31    fenv_t       type for object representing an entire floating-point
  32                 environment
  33
  34    FE_DFL_ENV   macro of type pointer to fenv_t to be used as the argument
  35                 to functions taking an argument of type fenv_t; in this
  36                 case the default environment will be used
  37
  38    fexcept_t    type for object representing the floating-point exception
  39                 flags including status associated with the flags
  40
  41    The following macros are defined iff the implementation supports this
  42    kind of exception.
  43    FE_INEXACT           inexact result
  44    FE_DIVBYZERO         division by zero
  45    FE_UNDERFLOW         result not representable due to underflow
  46    FE_OVERFLOW          result not representable due to overflow
  47    FE_INVALID           invalid operation
  48
  49    FE_ALL_EXCEPT        bitwise OR of all supported exceptions
  50
  51    The next macros are defined iff the appropriate rounding mode is
  52    supported by the implementation.
  53    FE_TONEAREST         round to nearest
  54    FE_UPWARD            round toward +Inf
  55    FE_DOWNWARD          round toward -Inf
  56    FE_TOWARDZERO        round toward 0
  57 */
  58 #include <bits/fenv.h>
  59
  60 __BEGIN_DECLS
  61
  62 /* Floating-point exception handling.  */
  63
  64 /* Clear the supported exceptions represented by EXCEPTS.  */
  65 extern int feclearexcept (int __excepts) __THROW;
  66
  67 /* Store implementation-defined representation of the exception flags
  68    indicated by EXCEPTS in the object pointed to by FLAGP.  */
  69 extern int fegetexceptflag (fexcept_t *__flagp, int __excepts) __THROW;
  70
  71 /* Raise the supported exceptions represented by EXCEPTS.  */
  72 extern int feraiseexcept (int __excepts) __THROW;
  73
  74 /* Set complete status for exceptions indicated by EXCEPTS according to
  75    the representation in the object pointed to by FLAGP.  */
  76 extern int fesetexceptflag (__const fexcept_t *__flagp, int __excepts) __THROW;
  77
  78 /* Determine which of subset of the exceptions specified by EXCEPTS are
  79    currently set.  */
  80 extern int fetestexcept (int __excepts) __THROW;
  81
  82
  83 /* Rounding control.  */
  84
  85 /* Get current rounding direction.  */
  86 extern int fegetround (void) __THROW;
  87
  88 /* Establish the rounding direction represented by ROUND.  */
  89 extern int fesetround (int __rounding_direction) __THROW;
  90
  91
  92 /* Floating-point environment.  */
  93
  94 /* Store the current floating-point environment in the object pointed
  95    to by ENVP.  */
  96 extern int fegetenv (fenv_t *__envp) __THROW;
  97
  98 /* Save the current environment in the object pointed to by ENVP, clear
  99    exception flags and install a non-stop mode (if available) for all
 100    exceptions.  */
 101 extern int feholdexcept (fenv_t *__envp) __THROW;
 102
 103 /* Establish the floating-point environment represented by the object
 104    pointed to by ENVP.  */
 105 extern int fesetenv (__const fenv_t *__envp) __THROW;
 106
 107 /* Save current exceptions in temporary storage, install environment
 108    represented by object pointed to by ENVP and raise exceptions
 109    according to saved exceptions.  */
 110 extern int feupdateenv (__const fenv_t *__envp) __THROW;
 111
 112
 113 /* Include optimization.  */
 114 #ifdef __OPTIMIZE__
 115 # include <bits/fenvinline.h>
 116 #endif
 117
 118 #ifdef __USE_GNU
 119
 120 /* Enable individual exceptions.  Will not enable more exceptions than
 121    EXCEPTS specifies.  Returns the previous enabled exceptions if all
 122    exceptions are successfully set, otherwise returns -1.  */
 123 extern int feenableexcept (int __excepts) __THROW;
 124
 125 /* Disable individual exceptions.  Will not disable more exceptions than
 126    EXCEPTS specifies.  Returns the previous enabled exceptions if all
 127    exceptions are successfully disabled, otherwise returns -1.  */
 128 extern int fedisableexcept (int __excepts) __THROW;
 129
 130 /* Return enabled exceptions.  */
 131 extern int fegetexcept (void) __THROW;
 132 #endif
 133
 134 __END_DECLS
 135
 136 #endif /* fenv.h */