| /* Round double to integer away from zero. |
| Copyright (C) 1997 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) |
| { |
| int32_t i0, j0; |
| u_int32_t i1; |
| |
| EXTRACT_WORDS (i0, i1, x); |
| j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; |
| if (j0 < 20) |
| { |
| if (j0 < 0) |
| { |
| if (huge + x > 0.0) |
| { |
| i0 &= 0x80000000; |
| if (j0 == -1) |
| i0 |= 0x3ff00000; |
| i1 = 0; |
| } |
| } |
| else |
| { |
| u_int32_t i = 0x000fffff >> j0; |
| if (((i0 & i) | i1) == 0) |
| /* X is integral. */ |
| return x; |
| if (huge + x > 0.0) |
| { |
| /* Raise inexact if x != 0. */ |
| i0 += 0x00080000 >> j0; |
| i0 &= ~i; |
| i1 = 0; |
| } |
| } |
| } |
| else if (j0 > 51) |
| { |
| if (j0 == 0x400) |
| /* Inf or NaN. */ |
| return x + x; |
| else |
| return x; |
| } |
| else |
| { |
| u_int32_t i = 0xffffffff >> (j0 - 20); |
| if ((i1 & i) == 0) |
| /* X is integral. */ |
| return x; |
| |
| if (huge + x > 0.0) |
| { |
| /* Raise inexact if x != 0. */ |
| u_int32_t j = i1 + (1 << (51 - j0)); |
| if (j < i1) |
| i0 += 1; |
| i1 = j; |
| } |
| i1 &= ~i; |
| } |
| |
| INSERT_WORDS (x, i0, i1); |
| return x; |
| } |
| weak_alias (__round, round) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__round, __roundl) |
| weak_alias (__round, roundl) |
| #endif |
