Return to add.c CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / php / ext / bcmath / libbcmath / src

Annotation of embedaddon/php/ext/bcmath/libbcmath/src/add.c, revision 1.1

1.1     ! misho       1: /* add.c: bcmath library file. */
        !             2: /*
        !             3:     Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
        !             4:     Copyright (C) 2000 Philip A. Nelson
        !             5: 
        !             6:     This library is free software; you can redistribute it and/or
        !             7:     modify it under the terms of the GNU Lesser General Public
        !             8:     License as published by the Free Software Foundation; either
        !             9:     version 2 of the License, or (at your option) any later version.
        !            10: 
        !            11:     This library is distributed in the hope that it will be useful,
        !            12:     but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            13:     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
        !            14:     Lesser General Public License for more details.  (COPYING.LIB)
        !            15: 
        !            16:     You should have received a copy of the GNU Lesser General Public
        !            17:     License along with this library; if not, write to:
        !            18: 
        !            19:       The Free Software Foundation, Inc.
        !            20:       59 Temple Place, Suite 330
        !            21:       Boston, MA 02111-1307 USA.
        !            22: 
        !            23:     You may contact the author by:
        !            24:        e-mail:  philnelson@acm.org
        !            25:       us-mail:  Philip A. Nelson
        !            26:                 Computer Science Department, 9062
        !            27:                 Western Washington University
        !            28:                 Bellingham, WA 98226-9062
        !            29:        
        !            30: *************************************************************************/
        !            31: 
        !            32: #include <config.h>
        !            33: #include <stdio.h>
        !            34: #include <assert.h>
        !            35: #include <stdlib.h>
        !            36: #include <ctype.h>
        !            37: #include <stdarg.h>
        !            38: #include "bcmath.h"
        !            39: #include "private.h"
        !            40: 
        !            41: 
        !            42: /* Here is the full add routine that takes care of negative numbers.
        !            43:    N1 is added to N2 and the result placed into RESULT.  SCALE_MIN
        !            44:    is the minimum scale for the result. */
        !            45: 
        !            46: void
        !            47: bc_add (n1, n2, result, scale_min)
        !            48:      bc_num n1, n2, *result;
        !            49:      int scale_min;
        !            50: {
        !            51:   bc_num sum = NULL;
        !            52:   int cmp_res;
        !            53:   int res_scale;
        !            54: 
        !            55:   if (n1->n_sign == n2->n_sign)
        !            56:     {
        !            57:       sum = _bc_do_add (n1, n2, scale_min);
        !            58:       sum->n_sign = n1->n_sign;
        !            59:     }
        !            60:   else
        !            61:     {
        !            62:       /* subtraction must be done. */
        !            63:       cmp_res = _bc_do_compare (n1, n2, FALSE, FALSE);  /* Compare magnitudes. */
        !            64:       switch (cmp_res)
        !            65:        {
        !            66:        case -1:
        !            67:          /* n1 is less than n2, subtract n1 from n2. */
        !            68:          sum = _bc_do_sub (n2, n1, scale_min);
        !            69:          sum->n_sign = n2->n_sign;
        !            70:          break;
        !            71:        case  0:
        !            72:          /* They are equal! return zero with the correct scale! */
        !            73:          res_scale = MAX (scale_min, MAX(n1->n_scale, n2->n_scale));
        !            74:          sum = bc_new_num (1, res_scale);
        !            75:          memset (sum->n_value, 0, res_scale+1);
        !            76:          break;
        !            77:        case  1:
        !            78:          /* n2 is less than n1, subtract n2 from n1. */
        !            79:          sum = _bc_do_sub (n1, n2, scale_min);
        !            80:          sum->n_sign = n1->n_sign;
        !            81:        }
        !            82:     }
        !            83: 
        !            84:   /* Clean up and return. */
        !            85:   bc_free_num (result);
        !            86:   *result = sum;
        !            87: }
        !            88: