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
37
38
39
40
41
42
43
44
45
|
/* s_rintf.c -- float version of s_rint.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include <math.h>
#include "math_private.h"
static const float
TWO23[2]={
8.3886080000e+06, /* 0x4b000000 */
-8.3886080000e+06, /* 0xcb000000 */
};
float
rintf(float x)
{
int32_t i0,j0,sx;
volatile float w,t; /* volatile works around gcc bug */
GET_FLOAT_WORD(i0,x);
sx = (i0>>31)&1;
j0 = ((i0>>23)&0xff)-0x7f;
if(j0<23) {
if(j0<0) {
if((i0&0x7fffffff)==0) return x;
w = TWO23[sx]+x;
t = w-TWO23[sx];
return t;
}
w = TWO23[sx]+x;
return w-TWO23[sx];
}
if(j0==0x80) return x+x; /* inf or NaN */
else return x; /* x is integral */
}
|
