| /* Round to nearest integer value, rounding halfway cases to even. |
| ldbl-128ibm version. |
| 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> |
| |
| long double |
| __roundevenl (long double x) |
| { |
| double xh, xl, hi; |
| |
| ldbl_unpack (x, &xh, &xl); |
| |
| if (xh != 0 && isfinite (xh)) |
| { |
| hi = __roundeven (xh); |
| if (hi != xh) |
| { |
| /* The high part is not an integer; the low part only |
| affects the result if the high part is exactly half way |
| between two integers and the low part is nonzero in the |
| opposite direction to the rounding of the high part. */ |
| double diff = hi - xh; |
| if (fabs (diff) == 0.5) |
| { |
| if (xl < 0 && diff > 0) |
| xh = hi - 1; |
| else if (xl > 0 && diff < 0) |
| xh = hi + 1; |
| else |
| xh = hi; |
| } |
| else |
| xh = hi; |
| xl = 0; |
| } |
| else |
| { |
| /* The high part is a nonzero integer. Rounding the low |
| part to nearest, ties round to even, is always correct, |
| as a high part that is an odd integer together with a low |
| part with magnitude 0.5 is not a valid long double. */ |
| xl = __roundeven (xl); |
| xh = hi; |
| ldbl_canonicalize_int (&xh, &xl); |
| } |
| } |
| else |
| /* Quiet signaling NaN arguments. */ |
| xh += xh; |
| |
| return ldbl_pack (xh, xl); |
| } |
| weak_alias (__roundevenl, roundevenl) |