1 /* s_rintf.c -- float version of s_rint.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16 #include <float.h>
17 #include <stdint.h>
18
19 #include "math.h"
20 #include "math_private.h"
21
22 static const float
23 TWO23[2]={
24 8.3886080000e+06, /* 0x4b000000 */
25 -8.3886080000e+06, /* 0xcb000000 */
26 };
27
28 float
rintf(float x)29 rintf(float x)
30 {
31 int32_t i0,j0,sx;
32 float w,t;
33 GET_FLOAT_WORD(i0,x);
34 sx = (i0>>31)&1;
35 j0 = ((i0>>23)&0xff)-0x7f;
36 if(j0<23) {
37 if(j0<0) {
38 if((i0&0x7fffffff)==0) return x;
39 STRICT_ASSIGN(float,w,TWO23[sx]+x);
40 t = w-TWO23[sx];
41 GET_FLOAT_WORD(i0,t);
42 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
43 return t;
44 }
45 STRICT_ASSIGN(float,w,TWO23[sx]+x);
46 return w-TWO23[sx];
47 }
48 if(j0==0x80) return x+x; /* inf or NaN */
49 else return x; /* x is integral */
50 }
51