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| | #include "libm.h"
#ifdef LONG_DOUBLE_IS_BINARY64
long double truncl(long double x)
{
return trunc(x);
}
#elif defined(LONG_DOUBLE_IS_X87_EXTENDED) || defined(LONG_DOUBLE_IS_BINARY128)
static const long double toint = 1/LDBL_EPSILON;
long double truncl(long double x)
{
union ldshape u = {x};
int e = u.i.se & 0x7fff;
int s = u.i.se >> 15;
long double y;
if (e >= 0x3fff+LDBL_MANT_DIG-1)
return x;
if (e <= 0x3fff-1) {
FORCE_EVAL(x + 0x1p120f);
return x*0;
}
/* y = int(|x|) - |x|, where int(|x|) is an integer neighbor of |x| */
if (s)
x = -x;
y = x + toint - toint - x;
if (y > 0)
y -= 1;
x += y;
return s ? -x : x;
}
#endif
|