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

25 lines
582 B
C

#include <fenv.h>
#include <math.h>
long long
llround (double x) {
long long retval;
unsigned short saved_cw, _cw;
__asm__ (
"fnstcw %0;" : "=m" (saved_cw)
); /* save control word */
_cw = ~(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO)
| (x > 0.0 ? FE_UPWARD : FE_DOWNWARD); /* round away from zero */
__asm__ (
"fldcw %0;" : : "m" (_cw)
); /* load the rounding control */
__asm__ __volatile__ (
"fistpll %0" : "=m" (retval) : "t" (x) : "st"
);
__asm__ (
"fldcw %0;" : : "m" (saved_cw)
); /* restore control word */
return retval;
}