1/* nearbyintq.c -- __float128 version of s_nearbyint.c.
2 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
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/*
17 * nearbyintq(x)
18 * Return x rounded to integral value according to the prevailing
19 * rounding mode.
20 * Method:
21 * Using floating addition.
22 * Exception:
23 * Inexact flag raised if x not equal to rintq(x).
24 */
25
26#include "quadmath-imp.h"
27#ifdef HAVE_FENV_H
28# include <fenv.h>
29# if defined HAVE_FEHOLDEXCEPT && defined HAVE_FESETENV
30# define USE_FENV_H
31# endif
32#endif
33
34static const __float128
35TWO112[2]={
36 5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
37 -5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
38};
39
40__float128
41nearbyintq(__float128 x)
42{
43#ifdef USE_FENV_H
44 fenv_t env;
45#endif
46 int64_t i0,j0,sx;
47 uint64_t i1 __attribute__ ((unused));
48 __float128 w,t;
49 GET_FLT128_WORDS64(i0,i1,x);
50 sx = (((uint64_t)i0)>>63);
51 j0 = ((i0>>48)&0x7fff)-0x3fff;
52 if(j0<112) {
53 if(j0<0) {
54#ifdef USE_FENV_H
55 feholdexcept (&env);
56#endif
57 w = TWO112[sx]+x;
58 t = w-TWO112[sx];
59 math_force_eval (t);
60#ifdef USE_FENV_H
61 fesetenv (&env);
62#endif
63 GET_FLT128_MSW64(i0,t);
64 SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
65 return t;
66 }
67 } else {
68 if(j0==0x4000) return x+x; /* inf or NaN */
69 else return x; /* x is integral */
70 }
71#ifdef USE_FENV_H
72 feholdexcept (&env);
73#endif
74 w = TWO112[sx]+x;
75 t = w-TWO112[sx];
76 math_force_eval (t);
77#ifdef USE_FENV_H
78 fesetenv (&env);
79#endif
80 return t;
81}
82