1 /* rintq.c -- __float128 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 /*
17 * rintq(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
28 static const __float128
29 TWO112[2]={
30 5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
31 -5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
32 };
33
34 __float128
rintq(__float128 x)35 rintq (__float128 x)
36 {
37 int64_t i0,j0,sx;
38 uint64_t i1;
39 __float128 w,t;
40 GET_FLT128_WORDS64(i0,i1,x);
41 sx = (((uint64_t)i0)>>63);
42 j0 = ((i0>>48)&0x7fff)-0x3fff;
43 if(j0<112) {
44 if(j0<0) {
45 w = TWO112[sx]+x;
46 t = w-TWO112[sx];
47 GET_FLT128_MSW64(i0,t);
48 SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
49 return t;
50 }
51 } else {
52 if(j0==0x4000) return x+x; /* inf or NaN */
53 else return x; /* x is integral */
54 }
55 w = TWO112[sx]+x;
56 return w-TWO112[sx];
57 }
58