| /* Round double to integer away from zero. |
| Copyright (C) 1997, 2009 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. |
| |
| 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, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <math.h> |
| |
| #include "math_private.h" |
| |
| |
| static const double huge = 1.0e300; |
| |
| |
| double |
| __round (double x) |
| { |
| int64_t i0, j0; |
| |
| EXTRACT_WORDS64 (i0, x); |
| j0 = ((i0 >> 52) & 0x7ff) - 0x3ff; |
| if (__builtin_expect (j0 < 52, 1)) |
| { |
| if (j0 < 0) |
| { |
| if (huge + x > 0.0) |
| { |
| i0 &= UINT64_C(0x8000000000000000); |
| if (j0 == -1) |
| i0 |= UINT64_C(0x3ff0000000000000); |
| } |
| } |
| else |
| { |
| uint64_t i = UINT64_C(0x000fffffffffffff) >> j0; |
| if ((i0 & i) == 0) |
| /* X is integral. */ |
| return x; |
| if (huge + x > 0.0) |
| { |
| /* Raise inexact if x != 0. */ |
| i0 += UINT64_C(0x0008000000000000) >> j0; |
| i0 &= ~i; |
| } |
| } |
| } |
| else |
| { |
| if (j0 == 0x400) |
| /* Inf or NaN. */ |
| return x + x; |
| else |
| return x; |
| } |
| |
| INSERT_WORDS64 (x, i0); |
| return x; |
| } |
| weak_alias (__round, round) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__round, __roundl) |
| weak_alias (__round, roundl) |
| #endif |
