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

30 lines
563 B
C

#include <fenv.h>
double
round (double x) {
double 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__ (
"frndint;"
: "=t" (retval)
: "0" (x)
); /* do the rounding */
__asm__ (
"fldcw %0;"
:
: "m" (saved_cw)
); /* restore control word */
return retval;
}