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

20 lines
448 B
C

#include <math.h>
#include <limits.h>
#include <errno.h>
long
lround (double x)
{
/* Add +/- 0.5 then then round towards zero. */
double tmp = trunc (x + (x >= 0.0 ? 0.5 : -0.5));
if (!isfinite (tmp)
|| tmp > (double)LONG_MAX
|| tmp < (double)LONG_MIN)
{
errno = ERANGE;
/* Undefined behaviour, so we could return anything. */
/* return tmp > 0.0 ? LONG_MAX : LONG_MIN; */
}
return (long)tmp;
}