source: azure_iot_hub/trunk/musl-1.1.18/src/math/lrintl.c@ 388

#include <limits.h>
#include <fenv.h>
#include "libm.h"


#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long lrintl(long double x)
{
        return lrint(x);
}
#elif defined(FE_INEXACT)
/*
see comments in lrint.c

Note that if LONG_MAX == 0x7fffffffffffffff && LDBL_MANT_DIG == 64
then x == 2**63 - 0.5 is the only input that overflows and
raises inexact (with tonearest or upward rounding mode)
*/
long lrintl(long double x)
{
        #pragma STDC FENV_ACCESS ON
        int e;

        e = fetestexcept(FE_INEXACT);
        x = rintl(x);
        if (!e && (x > LONG_MAX || x < LONG_MIN))
                feclearexcept(FE_INEXACT);
        /* conversion */
        return x;
}
#else
long lrintl(long double x)
{
        return rintl(x);
}
#endif