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Annotation of OpenXM_contrib/gmp/mpz/mul.c, Revision 1.1.1.3

1.1       maekawa     1: /* mpz_mul -- Multiply two integers.
                      2:
1.1.1.3 ! ohara       3: Copyright 1991, 1993, 1994, 1996, 2000, 2001 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:
1.1.1.3 ! ohara      29:
1.1       maekawa    30: void
1.1.1.3 ! ohara      31: #ifndef BERKELEY_MP
1.1       maekawa    32: mpz_mul (mpz_ptr w, mpz_srcptr u, mpz_srcptr v)
                     33: #else /* BERKELEY_MP */
                     34: mult (mpz_srcptr u, mpz_srcptr v, mpz_ptr w)
                     35: #endif /* BERKELEY_MP */
                     36: {
                     37:   mp_size_t usize = u->_mp_size;
                     38:   mp_size_t vsize = v->_mp_size;
                     39:   mp_size_t wsize;
                     40:   mp_size_t sign_product;
                     41:   mp_ptr up, vp;
                     42:   mp_ptr wp;
1.1.1.3 ! ohara      43:   mp_ptr free_me;
1.1       maekawa    44:   size_t free_me_size;
                     45:   mp_limb_t cy_limb;
                     46:   TMP_DECL (marker);
                     47:
                     48:   sign_product = usize ^ vsize;
                     49:   usize = ABS (usize);
                     50:   vsize = ABS (vsize);
                     51:
                     52:   if (usize < vsize)
                     53:     {
1.1.1.3 ! ohara      54:       MPZ_SRCPTR_SWAP (u, v);
        !            55:       MP_SIZE_T_SWAP (usize, vsize);
1.1       maekawa    56:     }
                     57:
1.1.1.3 ! ohara      58:   if (vsize == 0)
        !            59:     {
        !            60:       SIZ(w) = 0;
        !            61:       return;
        !            62:     }
        !            63:
        !            64: #if HAVE_NATIVE_mpn_mul_2
        !            65:   if (vsize <= 2)
        !            66:     {
        !            67:       MPZ_REALLOC (w, usize+vsize);
        !            68:       wp = PTR(w);
        !            69:       if (vsize == 1)
        !            70:         cy_limb = mpn_mul_1 (wp, PTR(u), usize, PTR(v)[0]);
        !            71:       else
        !            72:         {
        !            73:           cy_limb = mpn_mul_2 (wp, PTR(u), usize, PTR(v));
        !            74:           usize++;
        !            75:         }
        !            76:       wp[usize] = cy_limb;
        !            77:       usize += (cy_limb != 0);
        !            78:       SIZ(w) = (sign_product >= 0 ? usize : -usize);
        !            79:       return;
        !            80:     }
        !            81: #else
        !            82:   if (vsize == 1)
        !            83:     {
        !            84:       MPZ_REALLOC (w, usize+1);
        !            85:       wp = PTR(w);
        !            86:       cy_limb = mpn_mul_1 (wp, PTR(u), usize, PTR(v)[0]);
        !            87:       wp[usize] = cy_limb;
        !            88:       usize += (cy_limb != 0);
        !            89:       SIZ(w) = (sign_product >= 0 ? usize : -usize);
        !            90:       return;
        !            91:     }
        !            92: #endif
        !            93:
        !            94:   TMP_MARK (marker);
        !            95:   free_me = NULL;
1.1       maekawa    96:   up = u->_mp_d;
                     97:   vp = v->_mp_d;
                     98:   wp = w->_mp_d;
                     99:
                    100:   /* Ensure W has space enough to store the result.  */
                    101:   wsize = usize + vsize;
                    102:   if (w->_mp_alloc < wsize)
                    103:     {
                    104:       if (wp == up || wp == vp)
                    105:        {
                    106:          free_me = wp;
                    107:          free_me_size = w->_mp_alloc;
                    108:        }
                    109:       else
1.1.1.3 ! ohara     110:        (*__gmp_free_func) (wp, w->_mp_alloc * BYTES_PER_MP_LIMB);
1.1       maekawa   111:
                    112:       w->_mp_alloc = wsize;
1.1.1.3 ! ohara     113:       wp = (mp_ptr) (*__gmp_allocate_func) (wsize * BYTES_PER_MP_LIMB);
1.1       maekawa   114:       w->_mp_d = wp;
                    115:     }
                    116:   else
                    117:     {
                    118:       /* Make U and V not overlap with W.  */
                    119:       if (wp == up)
                    120:        {
                    121:          /* W and U are identical.  Allocate temporary space for U.  */
                    122:          up = (mp_ptr) TMP_ALLOC (usize * BYTES_PER_MP_LIMB);
                    123:          /* Is V identical too?  Keep it identical with U.  */
                    124:          if (wp == vp)
                    125:            vp = up;
                    126:          /* Copy to the temporary space.  */
                    127:          MPN_COPY (up, wp, usize);
                    128:        }
                    129:       else if (wp == vp)
                    130:        {
                    131:          /* W and V are identical.  Allocate temporary space for V.  */
                    132:          vp = (mp_ptr) TMP_ALLOC (vsize * BYTES_PER_MP_LIMB);
                    133:          /* Copy to the temporary space.  */
                    134:          MPN_COPY (vp, wp, vsize);
                    135:        }
                    136:     }
                    137:
1.1.1.3 ! ohara     138:   cy_limb = mpn_mul (wp, up, usize, vp, vsize);
        !           139:   wsize = usize + vsize;
        !           140:   wsize -= cy_limb == 0;
1.1       maekawa   141:
                    142:   w->_mp_size = sign_product < 0 ? -wsize : wsize;
                    143:   if (free_me != NULL)
1.1.1.3 ! ohara     144:     (*__gmp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB);
1.1       maekawa   145:   TMP_FREE (marker);
                    146: }