| /* Round argument to nearest integral value according to current rounding |
| direction. |
| Copyright (C) 1997, 2004, 2006 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 two52[2] = |
| { |
| 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */ |
| -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */ |
| }; |
| |
| |
| long int |
| __lrint (double x) |
| { |
| int32_t j0; |
| u_int32_t i0,i1; |
| volatile double w; |
| double t; |
| long int result; |
| int sx; |
| |
| EXTRACT_WORDS (i0, i1, x); |
| j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; |
| sx = i0 >> 31; |
| i0 &= 0xfffff; |
| i0 |= 0x100000; |
| |
| if (j0 < 20) |
| { |
| w = two52[sx] + x; |
| t = w - two52[sx]; |
| EXTRACT_WORDS (i0, i1, t); |
| j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; |
| i0 &= 0xfffff; |
| i0 |= 0x100000; |
| |
| result = (j0 < 0 ? 0 : i0 >> (20 - j0)); |
| } |
| else if (j0 < (int32_t) (8 * sizeof (long int)) - 1) |
| { |
| if (j0 >= 52) |
| result = ((long int) i0 << (j0 - 20)) | (i1 << (j0 - 52)); |
| else |
| { |
| w = two52[sx] + x; |
| t = w - two52[sx]; |
| EXTRACT_WORDS (i0, i1, t); |
| j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; |
| i0 &= 0xfffff; |
| i0 |= 0x100000; |
| |
| if (j0 == 20) |
| result = (long int) i0; |
| else |
| result = ((long int) i0 << (j0 - 20)) | (i1 >> (52 - j0)); |
| } |
| } |
| else |
| { |
| /* The number is too large. It is left implementation defined |
| what happens. */ |
| return (long int) x; |
| } |
| |
| return sx ? -result : result; |
| } |
| |
| weak_alias (__lrint, lrint) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__lrint, __lrintl) |
| weak_alias (__lrint, lrintl) |
| #endif |
