| /* Return the least floating-point number greater than X. |
| Copyright (C) 2016-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <math.h> |
| #include <math_private.h> |
| #include <math_ldbl_opt.h> |
| |
| /* Return the least floating-point number greater than X. */ |
| long double |
| __nextupl (long double x) |
| { |
| int64_t hx, ihx, lx; |
| double xhi, xlo, yhi; |
| |
| ldbl_unpack (x, &xhi, &xlo); |
| EXTRACT_WORDS64 (hx, xhi); |
| EXTRACT_WORDS64 (lx, xlo); |
| ihx = hx & 0x7fffffffffffffffLL; |
| |
| if (ihx > 0x7ff0000000000000LL) /* x is nan. */ |
| return x + x; /* Signal the nan. */ |
| if (ihx == 0) |
| return LDBL_TRUE_MIN; |
| |
| long double u; |
| if ((hx == 0x7fefffffffffffffLL) && (lx == 0x7c8ffffffffffffeLL)) |
| return INFINITY; |
| if ((uint64_t) hx >= 0xfff0000000000000ULL) |
| { |
| u = -0x1.fffffffffffff7ffffffffffff8p+1023L; |
| return u; |
| } |
| if (ihx <= 0x0360000000000000LL) |
| { /* x <= LDBL_MIN. */ |
| x += LDBL_TRUE_MIN; |
| if (x == 0.0L) /* Handle negative LDBL_TRUE_MIN case. */ |
| x = -0.0L; |
| return x; |
| } |
| /* If the high double is an exact power of two and the low |
| double is the opposite sign, then 1ulp is one less than |
| what we might determine from the high double. Similarly |
| if X is an exact power of two, and negative, because |
| making it a little larger will result in the exponent |
| decreasing by one and normalisation of the mantissa. */ |
| if ((hx & 0x000fffffffffffffLL) == 0 |
| && ((lx != 0 && lx != 0x8000000000000000LL && (hx ^ lx) < 0) |
| || ((lx == 0 || lx == 0x8000000000000000LL) && hx < 0))) |
| ihx -= 1LL << 52; |
| if (ihx < (106LL << 52)) |
| { /* ulp will denormal. */ |
| INSERT_WORDS64 (yhi, ihx & (0x7ffLL << 52)); |
| u = yhi * 0x1p-105; |
| } |
| else |
| { |
| INSERT_WORDS64 (yhi, (ihx & (0x7ffLL << 52)) - (105LL << 52)); |
| u = yhi; |
| } |
| return x + u; |
| } |
| |
| weak_alias (__nextupl, nextupl) |
