1 | /* Set NaN payload. ldbl-96 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 62 |
27 | #define EXPLICIT_MANT_DIG 63 |
28 | |
29 | int |
30 | FUNC (long double *x, long double payload) |
31 | { |
32 | uint32_t hx, lx; |
33 | uint16_t exponent; |
34 | GET_LDOUBLE_WORDS (exponent, hx, lx, payload); |
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 |
39 | && exponent == 0 && hx == 0 && lx == 0))) |
40 | { |
41 | SET_LDOUBLE_WORDS (*x, 0, 0, 0); |
42 | return 1; |
43 | } |
44 | int shift = BIAS + EXPLICIT_MANT_DIG - exponent; |
45 | if (shift < 32 |
46 | ? (lx & ((1U << shift) - 1)) != 0 |
47 | : (lx != 0 || (hx & ((1U << (shift - 32)) - 1)) != 0)) |
48 | { |
49 | SET_LDOUBLE_WORDS (*x, 0, 0, 0); |
50 | return 1; |
51 | } |
52 | if (exponent != 0) |
53 | { |
54 | if (shift >= 32) |
55 | { |
56 | lx = hx >> (shift - 32); |
57 | hx = 0; |
58 | } |
59 | else if (shift != 0) |
60 | { |
61 | lx = (lx >> shift) | (hx << (32 - shift)); |
62 | hx >>= shift; |
63 | } |
64 | } |
65 | hx |= 0x80000000 | (SET_HIGH_BIT ? 0x40000000 : 0); |
66 | SET_LDOUBLE_WORDS (*x, 0x7fff, hx, lx); |
67 | return 0; |
68 | } |
69 | |