1*2fe8fb19SBen Gras /* s_rintf.c -- float version of s_rint.c.
2*2fe8fb19SBen Gras * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3*2fe8fb19SBen Gras */
4*2fe8fb19SBen Gras
5*2fe8fb19SBen Gras /*
6*2fe8fb19SBen Gras * ====================================================
7*2fe8fb19SBen Gras * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*2fe8fb19SBen Gras *
9*2fe8fb19SBen Gras * Developed at SunPro, a Sun Microsystems, Inc. business.
10*2fe8fb19SBen Gras * Permission to use, copy, modify, and distribute this
11*2fe8fb19SBen Gras * software is freely granted, provided that this notice
12*2fe8fb19SBen Gras * is preserved.
13*2fe8fb19SBen Gras * ====================================================
14*2fe8fb19SBen Gras */
15*2fe8fb19SBen Gras
16*2fe8fb19SBen Gras #include <sys/cdefs.h>
17*2fe8fb19SBen Gras #if defined(LIBM_SCCS) && !defined(lint)
18*2fe8fb19SBen Gras __RCSID("$NetBSD: s_rintf.c,v 1.9 2008/04/25 22:21:53 christos Exp $");
19*2fe8fb19SBen Gras #endif
20*2fe8fb19SBen Gras
21*2fe8fb19SBen Gras #include "math.h"
22*2fe8fb19SBen Gras #include "math_private.h"
23*2fe8fb19SBen Gras
24*2fe8fb19SBen Gras static const float
25*2fe8fb19SBen Gras TWO23[2]={
26*2fe8fb19SBen Gras 8.3886080000e+06, /* 0x4b000000 */
27*2fe8fb19SBen Gras -8.3886080000e+06, /* 0xcb000000 */
28*2fe8fb19SBen Gras };
29*2fe8fb19SBen Gras
30*2fe8fb19SBen Gras float
rintf(float x)31*2fe8fb19SBen Gras rintf(float x)
32*2fe8fb19SBen Gras {
33*2fe8fb19SBen Gras int32_t i0,jj0,sx;
34*2fe8fb19SBen Gras u_int32_t i,i1;
35*2fe8fb19SBen Gras #ifdef __i386__ /* XXX gcc4 will omit the rounding otherwise */
36*2fe8fb19SBen Gras volatile
37*2fe8fb19SBen Gras #endif
38*2fe8fb19SBen Gras float w;
39*2fe8fb19SBen Gras float t;
40*2fe8fb19SBen Gras GET_FLOAT_WORD(i0,x);
41*2fe8fb19SBen Gras sx = (i0>>31)&1;
42*2fe8fb19SBen Gras jj0 = ((i0>>23)&0xff)-0x7f;
43*2fe8fb19SBen Gras if(jj0<23) {
44*2fe8fb19SBen Gras if(jj0<0) {
45*2fe8fb19SBen Gras if((i0&0x7fffffff)==0) return x;
46*2fe8fb19SBen Gras i1 = (i0&0x07fffff);
47*2fe8fb19SBen Gras i0 &= 0xfff00000;
48*2fe8fb19SBen Gras i0 |= ((i1|-i1)>>9)&0x400000;
49*2fe8fb19SBen Gras SET_FLOAT_WORD(x,i0);
50*2fe8fb19SBen Gras w = TWO23[sx]+x;
51*2fe8fb19SBen Gras t = w-TWO23[sx];
52*2fe8fb19SBen Gras GET_FLOAT_WORD(i0,t);
53*2fe8fb19SBen Gras SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
54*2fe8fb19SBen Gras return t;
55*2fe8fb19SBen Gras } else {
56*2fe8fb19SBen Gras i = (0x007fffff)>>jj0;
57*2fe8fb19SBen Gras if((i0&i)==0) return x; /* x is integral */
58*2fe8fb19SBen Gras i>>=1;
59*2fe8fb19SBen Gras if((i0&i)!=0) i0 = (i0&(~i))|((0x100000)>>jj0);
60*2fe8fb19SBen Gras }
61*2fe8fb19SBen Gras } else {
62*2fe8fb19SBen Gras if(jj0==0x80) return x+x; /* inf or NaN */
63*2fe8fb19SBen Gras else return x; /* x is integral */
64*2fe8fb19SBen Gras }
65*2fe8fb19SBen Gras SET_FLOAT_WORD(x,i0);
66*2fe8fb19SBen Gras w = TWO23[sx]+x;
67*2fe8fb19SBen Gras return w-TWO23[sx];
68*2fe8fb19SBen Gras }
69