FECLEAREXCEPT(3) | Library Functions Manual | FECLEAREXCEPT(3) |
feclearexcept
, fegetexceptflag
,
feraiseexcept
,
fesetexceptflag
, fetestexcept
—
#include <fenv.h>
#pragma STDC FENV_ACCESS ON
int
feclearexcept
(int
excepts);
int
fegetexceptflag
(fexcept_t
*flagp, int
excepts);
int
feraiseexcept
(int
excepts);
int
fesetexceptflag
(const
fexcept_t *flagp, int
excepts);
int
fetestexcept
(int
excepts);
feclearexcept
() routine clears the floating-point
exception flags specified by excepts, whereas
feraiseexcept
() raises the specified exceptions.
Raising an exception causes the corresponding flag to be set, and a
SIGFPE
is delivered to the process if the exception is
unmasked.
The fetestexcept
() function determines
which flags are currently set, of those specified by
excepts.
The fegetexceptflag
() function stores the
state of the exception flags specified in excepts in
the opaque object pointed to by flagp. Similarly,
fesetexceptflag
() changes the specified exception
flags to reflect the state stored in the object pointed to by
flagp. Note that the flags restored with
fesetexceptflag
() must be a (not necessarily proper)
subset of the flags recorded by a prior call to
fegetexceptflag
().
For all of these functions, the possible types of exceptions include those described in fenv(3). Some architectures may define other types of floating-point exceptions.
The fegetexceptflag
() and
fesetexceptflag
() routines are preferred to
fetestexcept
() and
feraiseexcept
(), respectively, for saving and
restoring exception flags. The latter do not re-raise exceptions and may
preserve architecture-specific information such as addresses where
exceptions occurred.
feclearexcept
(),
fegetexceptflag
(),
feraiseexcept
(), and
fesetexceptflag
() functions return 0 upon success, and
non-zero otherwise. The fetestexcept
() function
returns the bitwise OR of the values of the current exception flags that were
requested.
feclearexcept
(),
fegetexceptflag
(),
feraiseexcept
(),
fesetexceptflag
(), and
fetestexcept
() routines conform to
ISO/IEC 9899:1999 (“ISO C99”).
May 8, 2004 | NetBSD 9.2 |