newlib-cygwin/winsup/mingw/mingwex/math/modfl.c

23 lines
672 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);
}