zig/lib/libc/mingw/math/lround.c

38 lines
762 B
C

/**
* This file has no copyright assigned and is placed in the Public Domain.
* This file is part of the mingw-w64 runtime package.
* No warranty is given; refer to the file DISCLAIMER.PD within this package.
*/
#include <math.h>
#include <limits.h>
#include <errno.h>
long
lround (double x)
{
double res;
if (x >= 0.0)
{
res = ceil (x);
if (res - x > 0.5)
res -= 1.0;
}
else
{
res = ceil (-x);
if (res + x > 0.5)
res -= 1.0;
res = -res;
}
if (!isfinite (res)
|| res > (double) LONG_MAX
|| res < (double) LONG_MIN)
{
errno = ERANGE;
/* Undefined behaviour, so we could return anything. */
/* return res > 0.0 ? LONG_MAX : LONG_MIN; */
}
return (long) res;
}