1 /* s_rintl.c -- long double version of s_rint.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 #if defined(LIBM_SCCS) && !defined(lint)
17 static char rcsid[] = "$NetBSD: $";
18 #endif
19
20 /*
21 * rintq(x)
22 * Return x rounded to integral value according to the prevailing
23 * rounding mode.
24 * Method:
25 * Using floating addition.
26 * Exception:
27 * Inexact flag raised if x not equal to rintq(x).
28 */
29
30 #define NO_MATH_REDIRECT
31
32 #include "quadmath-imp.h"
33
34 static const __float128
35 TWO112[2]={
36 5.19229685853482762853049632922009600E+33L, /* 0x406F000000000000, 0 */
37 -5.19229685853482762853049632922009600E+33L /* 0xC06F000000000000, 0 */
38 };
39
rintq(__float128 x)40 __float128 rintq(__float128 x)
41 {
42 int64_t i0,j0,sx;
43 uint64_t i1 __attribute__ ((unused));
44 __float128 w,t;
45 GET_FLT128_WORDS64(i0,i1,x);
46 sx = (((uint64_t)i0)>>63);
47 j0 = ((i0>>48)&0x7fff)-0x3fff;
48 if(j0<112) {
49 if(j0<0) {
50 w = TWO112[sx]+x;
51 t = w-TWO112[sx];
52 GET_FLT128_MSW64(i0,t);
53 SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
54 return t;
55 }
56 } else {
57 if(j0==0x4000) return x+x; /* inf or NaN */
58 else return x; /* x is integral */
59 }
60 w = TWO112[sx]+x;
61 return w-TWO112[sx];
62 }
63