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 <sys/cdefs.h>
17 __FBSDID("$FreeBSD$");
18
19 #include <float.h>
20 #include <stdint.h>
21
22 #include "math.h"
23 #include "math_private.h"
24
25 static const float
26 TWO23[2]={
27 8.3886080000e+06, /* 0x4b000000 */
28 -8.3886080000e+06, /* 0xcb000000 */
29 };
30
31 float
rintf(float x)32 rintf(float x)
33 {
34 int32_t i0,j0,sx;
35 float w,t;
36 GET_FLOAT_WORD(i0,x);
37 sx = (i0>>31)&1;
38 j0 = ((i0>>23)&0xff)-0x7f;
39 if(j0<23) {
40 if(j0<0) {
41 if((i0&0x7fffffff)==0) return x;
42 STRICT_ASSIGN(float,w,TWO23[sx]+x);
43 t = w-TWO23[sx];
44 GET_FLOAT_WORD(i0,t);
45 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
46 return t;
47 }
48 STRICT_ASSIGN(float,w,TWO23[sx]+x);
49 return w-TWO23[sx];
50 }
51 if(j0==0x80) return x+x; /* inf or NaN */
52 else return x; /* x is integral */
53 }
54