#include <fenv.h>
int fegetround(void);
int fesetround(int round);
The fegetround() function shall get the current rounding direction.
The fesetround() function shall establish the rounding direction represented by its argument round. If the argument is not equal to the value of a rounding direction macro, the rounding direction is not changed.
The fegetround() function shall return the value of the rounding direction macro representing the current rounding direction or a negative value if there is no such rounding direction macro or the current rounding direction is not determinable.
The fesetround() function shall return a zero value if and only if the requested rounding direction was established.
No errors are defined.
The following sections are informative.
The following example saves, sets, and restores the rounding direction, reporting an error and aborting if setting the rounding direction fails:
#include <fenv.h>
#include <assert.h>
void f(int round_dir)
{
#pragma STDC FENV_ACCESS ON
int save_round;
int setround_ok;
save_round = fegetround();
setround_ok = fesetround(round_dir);
assert(setround_ok == 0);
/* ... */
fesetround(save_round);
/* ... */
}
The Base Definitions volume of IEEE Std 1003.1-2001, <fenv.h>