blob: e8210af5621aa392543616d308200ddb22523281 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
#include "libm.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 roundf(float x)
{
union {float f; uint32_t i;} u = {x};
int e = u.i >> 23 & 0xff;
float_t y;
if (e >= 0x7f+23)
return x;
if (u.i >> 31)
x = -x;
if (e < 0x7f-1) {
FORCE_EVAL(x + toint);
return 0*u.f;
}
y = x + toint - toint - x;
if (y > 0.5f)
y = y + x - 1;
else if (y <= -0.5f)
y = y + x + 1;
else
y = y + x;
if (u.i >> 31)
y = -y;
return y;
}
|