FEGETENV(3) | Library Functions Manual | FEGETENV(3) |
fegetenv
, feholdexcept
,
fesetenv
, feupdateenv
—
#include <fenv.h>
#pragma STDC FENV_ACCESS ON
int
fegetenv
(fenv_t
*envp);
int
feholdexcept
(fenv_t
*envp);
int
fesetenv
(const
fenv_t *envp);
int
feupdateenv
(const
fenv_t *envp);
The fegetenv
() function stores the current
floating-point environment in the object pointed to by
envp, whereas feholdexcept
()
saves the current environment, then clears all exception flags and masks all
floating-point exceptions.
The fesetenv
() function restores a
previously saved environment. The feupdateenv
()
function restores a saved environment as well, but it also raises any
exceptions that were set in the environment it replaces.
The feholdexcept
() function is often used
with feupdateenv
() or
fesetenv
() to suppress spurious exceptions that
occur as a result of intermediate computations. An example in
fenv(3) demonstrates how to do
this.
fegetenv
(), feholdexcept
(),
fesetenv
(), and feupdateenv
()
functions return 0 if they succeed, and non-zero otherwise.
fegetenv
(), feholdexcept
(),
fesetenv
(), and feupdateenv
()
functions conform to ISO/IEC 9899:1999
(“ISO C99”).
May 8, 2004 | NetBSD 9.0 |