/* Round argument to nearest integral value according to current rounding direction. Copyright (C) 1997, 2004 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 */ }; libm_hidden_proto(lrint) 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) { if (j0 < -1) return 0; else { w = two52[sx] + x; t = w - two52[sx]; EXTRACT_WORDS (i0, i1, t); j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; i0 &= 0xfffff; i0 |= 0x100000; result = 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; } libm_hidden_def(lrint)