fe_dec_getround() — Get the current rounding mode

Standards

Format

#define __STDC_WANT_DEC_FP__
#include <fenv.h>

int fe_dec_getround(void);

General description

The fe_dec_getround function gets the current rounding mode for decimal floating-point operations.

The following rounding modes are defined for decimal floating-point, and are located in fenv.h:

FE_DEC_DOWNWARD

rounds towards minus infinity

FE_DEC_TONEAREST

rounds to nearest

FE_DEC_TOWARDZERO

rounds toward zero

FE_DEC_UPWARD

rounds toward plus infinity

FE_DEC_TONEARESTFROMZERO

rounds to nearest, ties away from zero

_FE_DEC_AWAYFROMZERO

rounds away from zero

_FE_DEC_TONEARESTTOWARDZERO

rounds to nearest, ties toward zero

_FE_DEC_PREPAREFORSHORTER

rounds to prepare for shorter precision

Returned value

If successful, returns the value of the current rounding mode for decimal floating-point operations.

If there is no such rounding mode or the current rounding mode can't be determined returns -1.

Example

⁄* CELEBF77

   sample program that issues fe_dec_getround()⁄setround()

   This program calls fe_dec_getround() to get the DFP rounding mode.
   Then it will compare the returned value with FE_DEC_TONEAREST
   rounding mode. If not the same, it will call fe_dec_setround() to
   set the rounding mode to the desired value FE_DEC_TONEAREST.
 *⁄

#define __STDC_WANT_DEC_FP__
#include <fenv.h>
#include <stdlib.h>
#include <stdio.h>

int main(int argc, char *argv[]){
   int r;
   if ((r = fe_dec_getround()) == -1){
     perror("fe_dec_getround");
     exit (-1);
   }
   printf("The Decimal floating point rounding mode is %d\n", r);
   if (r != FE_DEC_TONEAREST){
   	 printf("The DFP rounding mode is not FE_DEC_TONEAREST.\n");
     if (fe_dec_setround(FE_DEC_TONEAREST) == -1){
     	 perror("fe_dec_setround");
     	 exit (-1);
     }
   }
   printf("The DFP rounding mode has been set to FE_DEC_TONEAREST.\n");
   return 0;
}

Related information

• fenv.h
• fe_dec_setround() — Set the current rounding mode