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Annotation of OpenXM_contrib/gmp/mpz/mul.c, Revision 1.1.1.2

1.1       maekawa     1: /* mpz_mul -- Multiply two integers.
                      2:
1.1.1.2 ! maekawa     3: Copyright (C) 1991, 1993, 1994, 1996, 2000 Free Software Foundation, Inc.
1.1       maekawa     4:
                      5: This file is part of the GNU MP Library.
                      6:
                      7: The GNU MP Library is free software; you can redistribute it and/or modify
1.1.1.2 ! maekawa     8: it under the terms of the GNU Lesser General Public License as published by
        !             9: the Free Software Foundation; either version 2.1 of the License, or (at your
1.1       maekawa    10: option) any later version.
                     11:
                     12: The GNU MP Library is distributed in the hope that it will be useful, but
                     13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
1.1.1.2 ! maekawa    14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1.1       maekawa    15: License for more details.
                     16:
1.1.1.2 ! maekawa    17: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    18: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
                     19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     20: MA 02111-1307, USA. */
                     21:
1.1.1.2 ! maekawa    22: #include <stdio.h> /* for NULL */
1.1       maekawa    23: #include "gmp.h"
                     24: #include "gmp-impl.h"
1.1.1.2 ! maekawa    25: #ifdef BERKELEY_MP
        !            26: #include "mp.h"
        !            27: #endif
1.1       maekawa    28:
                     29: #ifndef BERKELEY_MP
                     30: void
                     31: #if __STDC__
                     32: mpz_mul (mpz_ptr w, mpz_srcptr u, mpz_srcptr v)
                     33: #else
                     34: mpz_mul (w, u, v)
                     35:      mpz_ptr w;
                     36:      mpz_srcptr u;
                     37:      mpz_srcptr v;
                     38: #endif
                     39: #else /* BERKELEY_MP */
                     40: void
                     41: #if __STDC__
                     42: mult (mpz_srcptr u, mpz_srcptr v, mpz_ptr w)
                     43: #else
                     44: mult (u, v, w)
                     45:      mpz_srcptr u;
                     46:      mpz_srcptr v;
                     47:      mpz_ptr w;
                     48: #endif
                     49: #endif /* BERKELEY_MP */
                     50: {
                     51:   mp_size_t usize = u->_mp_size;
                     52:   mp_size_t vsize = v->_mp_size;
                     53:   mp_size_t wsize;
                     54:   mp_size_t sign_product;
                     55:   mp_ptr up, vp;
                     56:   mp_ptr wp;
                     57:   mp_ptr free_me = NULL;
                     58:   size_t free_me_size;
                     59:   mp_limb_t cy_limb;
                     60:   TMP_DECL (marker);
                     61:
                     62:   TMP_MARK (marker);
                     63:   sign_product = usize ^ vsize;
                     64:   usize = ABS (usize);
                     65:   vsize = ABS (vsize);
                     66:
                     67:   if (usize < vsize)
                     68:     {
                     69:       /* Swap U and V.  */
                     70:       {const __mpz_struct *t = u; u = v; v = t;}
                     71:       {mp_size_t t = usize; usize = vsize; vsize = t;}
                     72:     }
                     73:
                     74:   up = u->_mp_d;
                     75:   vp = v->_mp_d;
                     76:   wp = w->_mp_d;
                     77:
                     78:   /* Ensure W has space enough to store the result.  */
                     79:   wsize = usize + vsize;
                     80:   if (w->_mp_alloc < wsize)
                     81:     {
                     82:       if (wp == up || wp == vp)
                     83:        {
                     84:          free_me = wp;
                     85:          free_me_size = w->_mp_alloc;
                     86:        }
                     87:       else
                     88:        (*_mp_free_func) (wp, w->_mp_alloc * BYTES_PER_MP_LIMB);
                     89:
                     90:       w->_mp_alloc = wsize;
                     91:       wp = (mp_ptr) (*_mp_allocate_func) (wsize * BYTES_PER_MP_LIMB);
                     92:       w->_mp_d = wp;
                     93:     }
                     94:   else
                     95:     {
                     96:       /* Make U and V not overlap with W.  */
                     97:       if (wp == up)
                     98:        {
                     99:          /* W and U are identical.  Allocate temporary space for U.  */
                    100:          up = (mp_ptr) TMP_ALLOC (usize * BYTES_PER_MP_LIMB);
                    101:          /* Is V identical too?  Keep it identical with U.  */
                    102:          if (wp == vp)
                    103:            vp = up;
                    104:          /* Copy to the temporary space.  */
                    105:          MPN_COPY (up, wp, usize);
                    106:        }
                    107:       else if (wp == vp)
                    108:        {
                    109:          /* W and V are identical.  Allocate temporary space for V.  */
                    110:          vp = (mp_ptr) TMP_ALLOC (vsize * BYTES_PER_MP_LIMB);
                    111:          /* Copy to the temporary space.  */
                    112:          MPN_COPY (vp, wp, vsize);
                    113:        }
                    114:     }
                    115:
                    116:   if (vsize == 0)
                    117:     {
                    118:       wsize = 0;
                    119:     }
                    120:   else
                    121:     {
                    122:       cy_limb = mpn_mul (wp, up, usize, vp, vsize);
                    123:       wsize = usize + vsize;
                    124:       wsize -= cy_limb == 0;
                    125:     }
                    126:
                    127:   w->_mp_size = sign_product < 0 ? -wsize : wsize;
                    128:   if (free_me != NULL)
                    129:     (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB);
                    130:   TMP_FREE (marker);
                    131: }