cosmopolitan/libc/math/lrintl.c

37 lines
697 B
C

#include "libc/limits.h"
#include "libc/math/fenv.h"
#include "libc/math/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