contrib/gmp/mpz/iset_si.c

   1 /* mpz_init_set_si(dest,val) -- Make a new multiple precision in DEST and
   2    assign VAL to the new number.
   3
   4 Copyright 1991, 1993, 1994, 1995, 2000, 2001, 2002 Free Software Foundation,
   5 Inc.
   6
   7 This file is part of the GNU MP Library.
   8
   9 The GNU MP Library is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU Lesser General Public License as published by
  11 the Free Software Foundation; either version 3 of the License, or (at your
  12 option) any later version.
  13
  14 The GNU MP Library is distributed in the hope that it will be useful, but
  15 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  17 License for more details.
  18
  19 You should have received a copy of the GNU Lesser General Public License
  20 along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
  21
  22 #include "gmp.h"
  23 #include "gmp-impl.h"
  24
  25 void
  26 mpz_init_set_si (mpz_ptr dest, signed long int val)
  27 {
  28   mp_size_t size;
  29   mp_limb_t vl;
  30
  31   dest->_mp_alloc = 1;
  32   dest->_mp_d = (mp_ptr) (*__gmp_allocate_func) (BYTES_PER_MP_LIMB);
  33
  34   vl = (mp_limb_t) (unsigned long int) (val >= 0 ? val : -val);
  35
  36   dest->_mp_d[0] = vl & GMP_NUMB_MASK;
  37   size = vl != 0;
  38
  39 #if GMP_NAIL_BITS != 0
  40   if (vl > GMP_NUMB_MAX)
  41     {
  42       MPZ_REALLOC (dest, 2);
  43       dest->_mp_d[1] = vl >> GMP_NUMB_BITS;
  44       size = 2;
  45     }
  46 #endif
  47
  48   dest->_mp_size = val >= 0 ? size : -size;
  49 }