1/* Set NaN payload. ldbl-128 version.
2 Copyright (C) 2016-2017 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 <http://www.gnu.org/licenses/>. */
18
19#include <math.h>
20#include <math_private.h>
21#include <nan-high-order-bit.h>
22#include <stdint.h>
23
24#define SET_HIGH_BIT (HIGH_ORDER_BIT_IS_SET_FOR_SNAN ? SIG : !SIG)
25#define BIAS 0x3fff
26#define PAYLOAD_DIG 111
27#define EXPLICIT_MANT_DIG 112
28
29int
30FUNC (_Float128 *x, _Float128 payload)
31{
32 uint64_t hx, lx;
33 GET_LDOUBLE_WORDS64 (hx, lx, payload);
34 int exponent = hx >> (EXPLICIT_MANT_DIG - 64);
35 /* Test if argument is (a) negative or too large; (b) too small,
36 except for 0 when allowed; (c) not an integer. */
37 if (exponent >= BIAS + PAYLOAD_DIG
38 || (exponent < BIAS && !(SET_HIGH_BIT && hx == 0 && lx == 0)))
39 {
40 SET_LDOUBLE_WORDS64 (*x, 0, 0);
41 return 1;
42 }
43 int shift = BIAS + EXPLICIT_MANT_DIG - exponent;
44 if (shift < 64
45 ? (lx & ((1ULL << shift) - 1)) != 0
46 : (lx != 0 || (hx & ((1ULL << (shift - 64)) - 1)) != 0))
47 {
48 SET_LDOUBLE_WORDS64 (*x, 0, 0);
49 return 1;
50 }
51 if (exponent != 0)
52 {
53 hx &= (1ULL << (EXPLICIT_MANT_DIG - 64)) - 1;
54 hx |= 1ULL << (EXPLICIT_MANT_DIG - 64);
55 if (shift >= 64)
56 {
57 lx = hx >> (shift - 64);
58 hx = 0;
59 }
60 else if (shift != 0)
61 {
62 lx = (lx >> shift) | (hx << (64 - shift));
63 hx >>= shift;
64 }
65 }
66 hx |= 0x7fff000000000000ULL | (SET_HIGH_BIT ? 0x800000000000ULL : 0);
67 SET_LDOUBLE_WORDS64 (*x, hx, lx);
68 return 0;
69}
70