1#include "libm.h"
2
3#if FLT_EVAL_METHOD == 0
4#define EPS FLT_EPSILON
5#elif FLT_EVAL_METHOD == 1
6#define EPS DBL_EPSILON
7#elif FLT_EVAL_METHOD == 2
8#define EPS LDBL_EPSILON
9#endif
10static const float_t toint = 1 / EPS;
11
12float roundf(float x) {
13    union {
14        float f;
15        uint32_t i;
16    } u = {x};
17    int e = u.i >> 23 & 0xff;
18    float_t y;
19
20    if (e >= 0x7f + 23)
21        return x;
22    if (u.i >> 31)
23        x = -x;
24    if (e < 0x7f - 1) {
25        FORCE_EVAL(x + toint);
26        return 0 * u.f;
27    }
28    y = x + toint - toint - x;
29    if (y > 0.5f)
30        y = y + x - 1;
31    else if (y <= -0.5f)
32        y = y + x + 1;
33    else
34        y = y + x;
35    if (u.i >> 31)
36        y = -y;
37    return y;
38}
39