1#include "libm.h"
2
3double trunc(double x)
4{
5	union {double f; uint64_t i;} u = {x};
6	int e = (int)(u.i >> 52 & 0x7ff) - 0x3ff + 12;
7	uint64_t m;
8
9	if (e >= 52 + 12)
10		return x;
11	if (e < 12)
12		e = 1;
13	m = -1ULL >> e;
14	if ((u.i & m) == 0)
15		return x;
16	FORCE_EVAL(x + 0x1p120f);
17	u.i &= ~m;
18	return u.f;
19}
20