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Annotation of OpenXM_contrib/gmp/mpf/integer.c, Revision 1.1

1.1     ! maekawa     1: /* mpf_trunc, mpf_floor, mpf_ceil -- Assign a float from another float while
        !             2:    rounding it to an integer.
        !             3:
        !             4: Copyright (C) 1997, 1998, 2000 Free Software Foundation, Inc.
        !             5:
        !             6: This file is part of the GNU MP Library.
        !             7:
        !             8: The GNU MP Library is free software; you can redistribute it and/or modify
        !             9: it under the terms of the GNU Lesser General Public License as published by
        !            10: the Free Software Foundation; either version 2.1 of the License, or (at your
        !            11: option) any later version.
        !            12:
        !            13: The GNU MP Library is distributed in the hope that it will be useful, but
        !            14: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            15: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
        !            16: License for more details.
        !            17:
        !            18: You should have received a copy of the GNU Lesser General Public License
        !            19: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
        !            20: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
        !            21: MA 02111-1307, USA. */
        !            22:
        !            23: #include "gmp.h"
        !            24: #include "gmp-impl.h"
        !            25:
        !            26:
        !            27: #if defined (OPERATION_floor)
        !            28: #define _MPF_FLOOR_OR_CEIL
        !            29: #define FUNC_NAME mpf_floor
        !            30: #define MPF_FLOOR 1
        !            31: #define MPF_CEIL 0
        !            32:
        !            33: #elif defined (OPERATION_ceil)
        !            34: #define _MPF_FLOOR_OR_CEIL
        !            35: #define FUNC_NAME mpf_ceil
        !            36: #define MPF_CEIL 1
        !            37: #define MPF_FLOOR 0
        !            38:
        !            39: #elif defined (OPERATION_trunc)
        !            40: #define FUNC_NAME mpf_trunc
        !            41:
        !            42: #else
        !            43: Error, error, unrecognised OPERATION
        !            44: #endif
        !            45:
        !            46:
        !            47: #ifdef _MPF_FLOOR_OR_CEIL
        !            48: static int
        !            49: #if __STDC__
        !            50: mpn_zero_p (mp_ptr p, mp_size_t n)
        !            51: #else
        !            52: mpn_zero_p (p, n)
        !            53:      mp_ptr p;
        !            54:      mp_size_t n;
        !            55: #endif
        !            56: {
        !            57:   mp_size_t i;
        !            58:
        !            59:   for (i = 0; i < n; i++)
        !            60:     {
        !            61:       if (p[i] != 0)
        !            62:        return 0;
        !            63:     }
        !            64:
        !            65:   return 1;
        !            66: }
        !            67: #endif
        !            68:
        !            69: void
        !            70: #if __STDC__
        !            71: FUNC_NAME (mpf_ptr r, mpf_srcptr u)
        !            72: #else
        !            73: FUNC_NAME (r, u)
        !            74:      mpf_ptr r;
        !            75:      mpf_srcptr u;
        !            76: #endif
        !            77: {
        !            78:   mp_ptr rp, up;
        !            79:   mp_size_t size, asize;
        !            80:   mp_size_t prec;
        !            81:   mp_size_t ignored_n;
        !            82:   mp_exp_t exp;
        !            83:
        !            84:   size = u->_mp_size;
        !            85:   rp = r->_mp_d;
        !            86:   exp = u->_mp_exp;
        !            87:
        !            88:   /* Single out the case where |u| < 1.  */
        !            89:   if (exp <= 0)
        !            90:     {
        !            91: #ifdef _MPF_FLOOR_OR_CEIL
        !            92:       if ((MPF_FLOOR && size < 0) || (MPF_CEIL && size >= 0))
        !            93:        {
        !            94:          rp[0] = 1;
        !            95:          r->_mp_size = MPF_FLOOR ? -1 : 1;
        !            96:          r->_mp_exp = 1;
        !            97:          return;
        !            98:        }
        !            99: #endif
        !           100:       r->_mp_size = 0;
        !           101:       return;
        !           102:     }
        !           103:
        !           104:   prec = r->_mp_prec /* + 1 */;
        !           105:   asize = ABS (size);
        !           106:
        !           107: #ifdef _MPF_FLOOR_OR_CEIL
        !           108:   ignored_n = 0;
        !           109: #endif
        !           110:   up = u->_mp_d;
        !           111:
        !           112:   if (asize > prec)
        !           113:     {
        !           114: #ifdef _MPF_FLOOR_OR_CEIL
        !           115:       ignored_n = asize - prec;
        !           116: #endif
        !           117:       up += asize - prec;
        !           118:       asize = prec;
        !           119:     }
        !           120:
        !           121:   if (asize > exp)
        !           122:     {
        !           123:       long diff = asize - exp;
        !           124: #ifdef _MPF_FLOOR_OR_CEIL
        !           125:       ignored_n += diff;
        !           126: #endif
        !           127:       up += diff;
        !           128:       asize = exp;
        !           129:     }
        !           130:
        !           131: #ifdef _MPF_FLOOR_OR_CEIL
        !           132:   if (((MPF_FLOOR && size < 0) || (MPF_CEIL && size >= 0))
        !           133:       && ! mpn_zero_p (up - ignored_n, ignored_n))
        !           134:     {
        !           135:       mp_limb_t cy;
        !           136:       cy = mpn_add_1 (rp, up, asize, (mp_limb_t) 1);
        !           137:       if (cy != 0)
        !           138:        {
        !           139:          rp[asize++] = cy;
        !           140:          exp++;
        !           141:        }
        !           142:     }
        !           143:   else
        !           144: #endif
        !           145:   MPN_COPY_INCR (rp, up, asize);
        !           146:
        !           147:   r->_mp_exp = exp;
        !           148:   r->_mp_size = size >= 0 ? asize : -asize;
        !           149: }