23 lines
694 B
C
23 lines
694 B
C
|
#include <fenv.h>
|
||
|
|
#include <math.h>
|
||
|
|
#include <errno.h>
|
||
|
|
#define FE_ROUNDING_MASK \
|
||
|
|
(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO)
|
||
|
|
|
||
|
|
long double
|
||
|
|
modfl (long double value, long double* iptr)
|
||
|
|
{
|
||
|
|
long double int_part;
|
||
|
|
unsigned short saved_cw;
|
||
|
|
unsigned short tmp_cw;
|
||
|
|
/* truncate */
|
||
|
|
asm ("fnstcw %0;" : "=m" (saved_cw)); /* save control word */
|
||
|
|
tmp_cw = (saved_cw & ~FE_ROUNDING_MASK) | FE_TOWARDZERO;
|
||
|
|
asm ("fldcw %0;" : : "m" (tmp_cw));
|
||
|
|
asm ("frndint;" : "=t" (int_part) : "0" (value)); /* round */
|
||
|
|
asm ("fldcw %0;" : : "m" (saved_cw)); /* restore saved cw */
|
||
|
|
if (iptr)
|
||
|
|
*iptr = int_part;
|
||
|
|
return (isinf (value) ? 0.0L : value - int_part);
|
||
|
|
}
|