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:
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