| 1 | /* Return the least floating-point number greater than X. |
| 2 | Copyright (C) 2016-2020 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 | long double |
| 26 | __nextupl (long double x) |
| 27 | { |
| 28 | uint32_t hx, ix; |
| 29 | uint32_t lx; |
| 30 | int32_t esx; |
| 31 | |
| 32 | GET_LDOUBLE_WORDS (esx, hx, lx, x); |
| 33 | ix = esx & 0x7fff; |
| 34 | |
| 35 | if (((ix == 0x7fff) && (((hx & 0x7fffffff) | lx) != 0))) /* x is nan. */ |
| 36 | return x + x; |
| 37 | if ((ix | hx | lx) == 0) |
| 38 | return LDBL_TRUE_MIN; |
| 39 | if (esx >= 0) |
| 40 | { /* x > 0. */ |
| 41 | if (isinf (x)) |
| 42 | return x; |
| 43 | lx += 1; |
| 44 | if (lx == 0) |
| 45 | { |
| 46 | hx += 1; |
| 47 | #if LDBL_MIN_EXP == -16381 |
| 48 | if (hx == 0 || (esx == 0 && hx == 0x80000000)) |
| 49 | #else |
| 50 | if (hx == 0) |
| 51 | #endif |
| 52 | { |
| 53 | esx += 1; |
| 54 | hx |= 0x80000000; |
| 55 | } |
| 56 | } |
| 57 | } |
| 58 | else |
| 59 | { /* x < 0. */ |
| 60 | if (lx == 0) |
| 61 | { |
| 62 | #if LDBL_MIN_EXP == -16381 |
| 63 | if (hx <= 0x80000000 && esx != 0xffff8000) |
| 64 | { |
| 65 | esx -= 1; |
| 66 | hx = hx - 1; |
| 67 | if ((esx & 0x7fff) > 0) |
| 68 | hx |= 0x80000000; |
| 69 | } |
| 70 | else |
| 71 | hx -= 1; |
| 72 | #else |
| 73 | if (ix != 0 && hx == 0x80000000) |
| 74 | hx = 0; |
| 75 | if (hx == 0) |
| 76 | esx -= 1; |
| 77 | hx -= 1; |
| 78 | #endif |
| 79 | } |
| 80 | lx -= 1; |
| 81 | } |
| 82 | SET_LDOUBLE_WORDS (x, esx, hx, lx); |
| 83 | return x; |
| 84 | } |
| 85 | |
| 86 | libm_alias_ldouble (__nextup, nextup) |
| 87 | |