manpagez: man pages & more
man feupdateenv(3)
Home | html | info | man
fegetenv(3)              BSD Library Functions Manual              fegetenv(3)


NAME

     fegetenv, feholdexcept, fesetenv, feupdateenv -- functions providing
     access to the floating-point environment.


SYNOPSIS

     #include <fenv.h>

     int
     fegetenv(fenv_t *envp);

     int
     feholdexcept(fenvt_t *envp);

     int
     fesetenv(fenv_t *envp);

     int
     feupdateenv(fenv_t *envp);


DESCRIPTION

     These functions provide the means to manage the entire floating-point
     environment--including both status flags and control modes--as a single
     entity.

     The fegetenv() function attempts to store the current floating-point
     environment in the object pointed to by envp.  It returns zero if the
     environment was successfully stored, and a nonzero value otherwise.

     The feholdexcept() function saves the current floating-point environment
     in the object pointed to by envp, clears the floating-point status flags,
     and then installs a "non-stop" mode, if available, under which no traps
     are taken for floating-point exceptions (as is the case in default
     IEEE-754 floating-point execution).  It returns zero if and only if such
     a mode was successfully installed.

     The fesetenv() function attempts to establish the floating-point environ-
     ment represented by the object pointed to by envp.  This object shall
     have been set by a call to fegetenv() or feholdexcept(), or be equal to a
     floating-point environment macro defined in <fenv.h>.  Note that this
     function merely installs the floating-point status flags represented by
     its argument, and does not raise the corresponding floating-point excep-
     tions.  It returns zero if and only if the environment pointed to by envp
     was successfully installed.

     The feupdateenv() function attempts to save the currently raised float-
     ing-point flags, install the floating-point environment represented by
     *envp, and then raise the floating-point exceptions corresponding to the
     saved flags.  The object pointed to by envp shall have been set by a call
     to fegetenv() or feholdexcept(), or be equal to a floating-point environ-
     ment macro defined in <fenv.h>.  It returns zero if and only if all of
     the specified actions were successfully carried out.


SEE ALSO

     fenv(3), feclearexcept(3), fegetexceptflag(3), fegetround(3),
     feraiseexcept(3), fesetexceptflag(3), fesetround(3), feraiseexcept(3)


STANDARDS

     These functions conform to ISO/IEC 9899:TC3.

BSD                               May 9, 2011                              BSD

Mac OS X 10.8 - Generated Mon Aug 27 16:42:47 CDT 2012
© manpagez.com 2000-2024
Individual documents may contain additional copyright information.