1 /* mpz_mul -- Multiply two integers.
3 Copyright 1991, 1993, 1994, 1996, 2000, 2001, 2005 Free Software Foundation,
6 This file is part of the GNU MP Library.
8 The GNU MP Library is free software; you can redistribute it and/or modify
9 it under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or (at your
11 option) any later version.
13 The GNU MP Library is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
16 License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
21 #include <stdio.h> /* for NULL */
31 mpz_mul (mpz_ptr w, mpz_srcptr u, mpz_srcptr v)
32 #else /* BERKELEY_MP */
33 mult (mpz_srcptr u, mpz_srcptr v, mpz_ptr w)
34 #endif /* BERKELEY_MP */
36 mp_size_t usize = u->_mp_size;
37 mp_size_t vsize = v->_mp_size;
39 mp_size_t sign_product;
47 sign_product = usize ^ vsize;
53 MPZ_SRCPTR_SWAP (u, v);
54 MP_SIZE_T_SWAP (usize, vsize);
63 #if HAVE_NATIVE_mpn_mul_2
66 MPZ_REALLOC (w, usize+vsize);
69 cy_limb = mpn_mul_1 (wp, PTR(u), usize, PTR(v)[0]);
72 cy_limb = mpn_mul_2 (wp, PTR(u), usize, PTR(v));
76 usize += (cy_limb != 0);
77 SIZ(w) = (sign_product >= 0 ? usize : -usize);
83 MPZ_REALLOC (w, usize+1);
85 cy_limb = mpn_mul_1 (wp, PTR(u), usize, PTR(v)[0]);
87 usize += (cy_limb != 0);
88 SIZ(w) = (sign_product >= 0 ? usize : -usize);
99 /* Ensure W has space enough to store the result. */
100 wsize = usize + vsize;
101 if (w->_mp_alloc < wsize)
103 if (wp == up || wp == vp)
106 free_me_size = w->_mp_alloc;
109 (*__gmp_free_func) (wp, w->_mp_alloc * BYTES_PER_MP_LIMB);
111 w->_mp_alloc = wsize;
112 wp = (mp_ptr) (*__gmp_allocate_func) (wsize * BYTES_PER_MP_LIMB);
117 /* Make U and V not overlap with W. */
120 /* W and U are identical. Allocate temporary space for U. */
121 up = (mp_ptr) TMP_ALLOC (usize * BYTES_PER_MP_LIMB);
122 /* Is V identical too? Keep it identical with U. */
125 /* Copy to the temporary space. */
126 MPN_COPY (up, wp, usize);
130 /* W and V are identical. Allocate temporary space for V. */
131 vp = (mp_ptr) TMP_ALLOC (vsize * BYTES_PER_MP_LIMB);
132 /* Copy to the temporary space. */
133 MPN_COPY (vp, wp, vsize);
137 cy_limb = mpn_mul (wp, up, usize, vp, vsize);
138 wsize = usize + vsize;
139 wsize -= cy_limb == 0;
141 w->_mp_size = sign_product < 0 ? -wsize : wsize;
143 (*__gmp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB);