https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113455
--- Comment #5 from newbie-02 <newbie-02 at gmx dot de> ---
> If you're doing arithmetic with constant operands, it might be folded at
> compile time; make sure you're using -frounding-math to avoid that.
hmmmmm... that issue is left. From your comment I was in hope the following
program would work:
````
// compile with 'gcc -std=gnu99 -I/usr/local/include/dfp -frounding-math -o
round_constants_ties_away round_constants_ties_away.c -ldfp',
#define __STDC_WANT_DEC_FP__
// req. for decimal rounding mode,
#include <fenv.h>
// req. for decimal rounding mode,
#include <stdio.h>
// reg. e.g. printf and perror,
int main( int argc, char *argv[ ] ) {
fe_dec_setround( 4 );
printf( "fe_dec_rounding_mode : %d \n", fe_dec_getround() );
volatile _Decimal64 x1DD = 8.0000000000000015DD;
volatile _Decimal64 x2DD = 8.0000000000000025DD;
printf( "Read in of 8.0000000000000015 produced : %.17DE \n", x1DD );
printf( "Read in of 8.0000000000000025 produced : %.17DE \n", x2DD );
printf( "In operation it works : %.17DE \n", x2DD +
5E-16DD );
return( 0 );
}
````
It works, but doesn't round the constants as wanted:
````
└─$ ./round_constants_ties_away
fe_dec_rounding_mode : 4
Read in of 8.0000000000000015 produced : 8.00000000000000200E+00
Read in of 8.0000000000000025 produced : 8.00000000000000200E+00
In operation it works : 8.00000000000000300E+00
````
