source: asp3_tinet_ecnl_rx/trunk/musl-1.1.18/src/math/rintf.c@ 337

#include <float.h>
#include <math.h>
#include <stdint.h>

#if FLT_EVAL_METHOD==0
#define EPS FLT_EPSILON
#elif FLT_EVAL_METHOD==1
#define EPS DBL_EPSILON
#elif FLT_EVAL_METHOD==2
#define EPS LDBL_EPSILON
#endif
static const float_t toint = 1/EPS;

float rintf(float x)
{
        union {float f; uint32_t i;} u = {x};
        int e = u.i>>23 & 0xff;
        int s = u.i>>31;
        float_t y;

        if (e >= 0x7f+23)
                return x;
        if (s)
                y = x - toint + toint;
        else
                y = x + toint - toint;
        if (y == 0)
                return s ? -0.0f : 0.0f;
        return y;
}