30 lines
563 B
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;
|
|
}
|