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Annotation of OpenXM_contrib/gmp/mpz/get_str.c, Revision 1.1.1.1

1.1       maekawa     1: /* mpz_get_str (string, base, mp_src) -- Convert the multiple precision
                      2:    number MP_SRC to a string STRING of base BASE.  If STRING is NULL
                      3:    allocate space for the result.  In any case, return a pointer to the
                      4:    result.  If STRING is not NULL, the caller must ensure enough space is
                      5:    available to store the result.
                      6:
                      7: Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc.
                      8:
                      9: This file is part of the GNU MP Library.
                     10:
                     11: The GNU MP Library is free software; you can redistribute it and/or modify
                     12: it under the terms of the GNU Library General Public License as published by
                     13: the Free Software Foundation; either version 2 of the License, or (at your
                     14: option) any later version.
                     15:
                     16: The GNU MP Library is distributed in the hope that it will be useful, but
                     17: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
                     18: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
                     19: License for more details.
                     20:
                     21: You should have received a copy of the GNU Library General Public License
                     22: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
                     23: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     24: MA 02111-1307, USA. */
                     25:
                     26: #include "gmp.h"
                     27: #include "gmp-impl.h"
                     28:
                     29: char *
                     30: #if __STDC__
                     31: mpz_get_str (char *res_str, int base, mpz_srcptr x)
                     32: #else
                     33: mpz_get_str (res_str, base, x)
                     34:      char *res_str;
                     35:      int base;
                     36:      mpz_srcptr x;
                     37: #endif
                     38: {
                     39:   mp_ptr xp;
                     40:   mp_size_t x_size = x->_mp_size;
                     41:   unsigned char *str;
                     42:   char *return_str;
                     43:   size_t str_size;
                     44:   char *num_to_text;
                     45:   int i;
                     46:   TMP_DECL (marker);
                     47:
                     48:   TMP_MARK (marker);
                     49:   if (base >= 0)
                     50:     {
                     51:       if (base == 0)
                     52:        base = 10;
                     53:       num_to_text = "0123456789abcdefghijklmnopqrstuvwxyz";
                     54:     }
                     55:   else
                     56:     {
                     57:       base = -base;
                     58:       num_to_text = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
                     59:     }
                     60:
                     61:   /* We allways allocate space for the string.  If the caller passed a
                     62:      NULL pointer for RES_STR, we allocate permanent space and return
                     63:      a pointer to that to the caller.  */
                     64:   str_size = ((size_t) (ABS (x_size) * BITS_PER_MP_LIMB
                     65:                        * __mp_bases[base].chars_per_bit_exactly)) + 3;
                     66:   if (res_str == 0)
                     67:     {
                     68:       /* We didn't get a string from the user.  Allocate one (and return
                     69:         a pointer to it).  */
                     70:       res_str = (char *) (*_mp_allocate_func) (str_size);
                     71:       /* Make str, the variable used for raw result from mpn_get_str,
                     72:         point to the same string, but just after a possible minus sign.  */
                     73:       str = (unsigned char *) res_str + 1;
                     74:     }
                     75:   else
                     76:     {
                     77:       /* Use TMP_ALLOC to get temporary space, since we need a few extra bytes
                     78:         that we can't expect to caller to supply us with.  */
                     79:       str = (unsigned char *) TMP_ALLOC (str_size);
                     80:     }
                     81:
                     82:   return_str = res_str;
                     83:
                     84:   if (x_size == 0)
                     85:     {
                     86:       res_str[0] = '0';
                     87:       res_str[1] = 0;
                     88:       TMP_FREE (marker);
                     89:       return res_str;
                     90:     }
                     91:   if (x_size < 0)
                     92:     {
                     93:       *res_str++ = '-';
                     94:       x_size = -x_size;
                     95:     }
                     96:
                     97:   /* Move the number to convert into temporary space, since mpn_get_str
                     98:      clobbers its argument + needs one extra high limb....  */
                     99:   xp = (mp_ptr) TMP_ALLOC ((x_size + 1) * BYTES_PER_MP_LIMB);
                    100:   MPN_COPY (xp, x->_mp_d, x_size);
                    101:
                    102:   str_size = mpn_get_str (str, base, xp, x_size);
                    103:
                    104:   /* mpn_get_str might make some leading zeros.  Skip them.  */
                    105:   while (*str == 0)
                    106:     {
                    107:       str_size--;
                    108:       str++;
                    109:     }
                    110:
                    111:   /* Translate result to printable chars and move result to RES_STR.  */
                    112:   for (i = 0; i < str_size; i++)
                    113:     res_str[i] = num_to_text[str[i]];
                    114:   res_str[str_size] = 0;
                    115:
                    116:   TMP_FREE (marker);
                    117:   return return_str;
                    118: }