diff options
Diffstat (limited to 'gnu/lib/libgmp/mpz/get_str.c')
-rw-r--r-- | gnu/lib/libgmp/mpz/get_str.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/gnu/lib/libgmp/mpz/get_str.c b/gnu/lib/libgmp/mpz/get_str.c new file mode 100644 index 0000000..8ccf3ef --- /dev/null +++ b/gnu/lib/libgmp/mpz/get_str.c @@ -0,0 +1,118 @@ +/* mpz_get_str (string, base, mp_src) -- Convert the multiple precision + number MP_SRC to a string STRING of base BASE. If STRING is NULL + allocate space for the result. In any case, return a pointer to the + result. If STRING is not NULL, the caller must ensure enough space is + available to store the result. + +Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Library General Public License as published by +the Free Software Foundation; either version 2 of the License, or (at your +option) any later version. + +The GNU MP 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 Library General Public +License for more details. + +You should have received a copy of the GNU Library General Public License +along with the GNU MP Library; see the file COPYING.LIB. If not, write to +the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, +MA 02111-1307, USA. */ + +#include "gmp.h" +#include "gmp-impl.h" + +char * +#if __STDC__ +mpz_get_str (char *res_str, int base, mpz_srcptr x) +#else +mpz_get_str (res_str, base, x) + char *res_str; + int base; + mpz_srcptr x; +#endif +{ + mp_ptr xp; + mp_size_t x_size = x->_mp_size; + unsigned char *str; + char *return_str; + size_t str_size; + char *num_to_text; + int i; + TMP_DECL (marker); + + TMP_MARK (marker); + if (base >= 0) + { + if (base == 0) + base = 10; + num_to_text = "0123456789abcdefghijklmnopqrstuvwxyz"; + } + else + { + base = -base; + num_to_text = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; + } + + /* We allways allocate space for the string. If the caller passed a + NULL pointer for RES_STR, we allocate permanent space and return + a pointer to that to the caller. */ + str_size = ((size_t) (ABS (x_size) * BITS_PER_MP_LIMB + * __mp_bases[base].chars_per_bit_exactly)) + 3; + if (res_str == 0) + { + /* We didn't get a string from the user. Allocate one (and return + a pointer to it). */ + res_str = (char *) (*_mp_allocate_func) (str_size); + /* Make str, the variable used for raw result from mpn_get_str, + point to the same string, but just after a possible minus sign. */ + str = (unsigned char *) res_str + 1; + } + else + { + /* Use TMP_ALLOC to get temporary space, since we need a few extra bytes + that we can't expect to caller to supply us with. */ + str = (unsigned char *) TMP_ALLOC (str_size); + } + + return_str = res_str; + + if (x_size == 0) + { + res_str[0] = '0'; + res_str[1] = 0; + TMP_FREE (marker); + return res_str; + } + if (x_size < 0) + { + *res_str++ = '-'; + x_size = -x_size; + } + + /* Move the number to convert into temporary space, since mpn_get_str + clobbers its argument + needs one extra high limb.... */ + xp = (mp_ptr) TMP_ALLOC ((x_size + 1) * BYTES_PER_MP_LIMB); + MPN_COPY (xp, x->_mp_d, x_size); + + str_size = mpn_get_str (str, base, xp, x_size); + + /* mpn_get_str might make some leading zeros. Skip them. */ + while (*str == 0) + { + str_size--; + str++; + } + + /* Translate result to printable chars and move result to RES_STR. */ + for (i = 0; i < str_size; i++) + res_str[i] = num_to_text[str[i]]; + res_str[str_size] = 0; + + TMP_FREE (marker); + return return_str; +} |