1 /* Return the least floating-point number greater than X.
2    Copyright (C) 2016-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <float.h>
20 #include <math.h>
21 #include <math_private.h>
22 #include <libm-alias-ldouble.h>
23 
24 /* Return the least floating-point number greater than X.  */
25 _Float128
__nextupl(_Float128 x)26 __nextupl (_Float128 x)
27 {
28   int64_t hx, ix;
29   uint64_t lx;
30 
31   GET_LDOUBLE_WORDS64 (hx, lx, x);
32   ix = hx & 0x7fffffffffffffffLL;
33 
34   /* x is nan.  */
35   if (((ix >= 0x7fff000000000000LL)
36        && ((ix - 0x7fff000000000000LL) | lx) != 0))
37     return x + x;
38   if ((ix | lx) == 0)
39     return LDBL_TRUE_MIN;
40   if (hx >= 0)
41     {				/* x > 0.  */
42       if (isinf (x))
43         return x;
44       lx++;
45       if (lx == 0)
46         hx++;
47     }
48   else
49     {				/* x < 0.  */
50       if (lx == 0)
51         hx--;
52       lx--;
53     }
54   SET_LDOUBLE_WORDS64 (x, hx, lx);
55   return x;
56 }
57 
58 libm_alias_ldouble (__nextup, nextup)
59