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mul.c revision 1.1.1.1 
      1  1.1  mrg /* mpf_mul -- Multiply two floats.
      2  1.1  mrg 
      3  1.1  mrg Copyright 1993, 1994, 1996, 2001, 2005 Free Software Foundation, Inc.
      4  1.1  mrg 
      5  1.1  mrg This file is part of the GNU MP Library.
      6  1.1  mrg 
      7  1.1  mrg The GNU MP Library is free software; you can redistribute it and/or modify
      8  1.1  mrg it under the terms of the GNU Lesser General Public License as published by
      9  1.1  mrg the Free Software Foundation; either version 3 of the License, or (at your
     10  1.1  mrg option) any later version.
     11  1.1  mrg 
     12  1.1  mrg The GNU MP Library is distributed in the hope that it will be useful, but
     13  1.1  mrg WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
     14  1.1  mrg or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
     15  1.1  mrg License for more details.
     16  1.1  mrg 
     17  1.1  mrg You should have received a copy of the GNU Lesser General Public License
     18  1.1  mrg along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
     19  1.1  mrg 
     20  1.1  mrg #include "gmp.h"
     21  1.1  mrg #include "gmp-impl.h"
     22  1.1  mrg 
     23  1.1  mrg void
     24  1.1  mrg mpf_mul (mpf_ptr r, mpf_srcptr u, mpf_srcptr v)
     25  1.1  mrg {
     26  1.1  mrg   mp_srcptr up, vp;
     27  1.1  mrg   mp_size_t usize, vsize;
     28  1.1  mrg   mp_size_t sign_product;
     29  1.1  mrg   mp_size_t prec = r->_mp_prec;
     30  1.1  mrg   TMP_DECL;
     31  1.1  mrg 
     32  1.1  mrg   TMP_MARK;
     33  1.1  mrg   usize = u->_mp_size;
     34  1.1  mrg   vsize = v->_mp_size;
     35  1.1  mrg   sign_product = usize ^ vsize;
     36  1.1  mrg 
     37  1.1  mrg   usize = ABS (usize);
     38  1.1  mrg   vsize = ABS (vsize);
     39  1.1  mrg 
     40  1.1  mrg   up = u->_mp_d;
     41  1.1  mrg   vp = v->_mp_d;
     42  1.1  mrg   if (usize > prec)
     43  1.1  mrg     {
     44  1.1  mrg       up += usize - prec;
     45  1.1  mrg       usize = prec;
     46  1.1  mrg     }
     47  1.1  mrg   if (vsize > prec)
     48  1.1  mrg     {
     49  1.1  mrg       vp += vsize - prec;
     50  1.1  mrg       vsize = prec;
     51  1.1  mrg     }
     52  1.1  mrg 
     53  1.1  mrg   if (usize == 0 || vsize == 0)
     54  1.1  mrg     {
     55  1.1  mrg       r->_mp_size = 0;
     56  1.1  mrg       r->_mp_exp = 0;		/* ??? */
     57  1.1  mrg     }
     58  1.1  mrg   else
     59  1.1  mrg     {
     60  1.1  mrg       mp_size_t rsize;
     61  1.1  mrg       mp_limb_t cy_limb;
     62  1.1  mrg       mp_ptr rp, tp;
     63  1.1  mrg       mp_size_t adj;
     64  1.1  mrg 
     65  1.1  mrg       rsize = usize + vsize;
     66  1.1  mrg       tp = TMP_ALLOC_LIMBS (rsize);
     67  1.1  mrg       cy_limb = (usize >= vsize
     68  1.1  mrg 		 ? mpn_mul (tp, up, usize, vp, vsize)
     69  1.1  mrg 		 : mpn_mul (tp, vp, vsize, up, usize));
     70  1.1  mrg 
     71  1.1  mrg       adj = cy_limb == 0;
     72  1.1  mrg       rsize -= adj;
     73  1.1  mrg       prec++;
     74  1.1  mrg       if (rsize > prec)
     75  1.1  mrg 	{
     76  1.1  mrg 	  tp += rsize - prec;
     77  1.1  mrg 	  rsize = prec;
     78  1.1  mrg 	}
     79  1.1  mrg       rp = r->_mp_d;
     80  1.1  mrg       MPN_COPY (rp, tp, rsize);
     81  1.1  mrg       r->_mp_exp = u->_mp_exp + v->_mp_exp - adj;
     82  1.1  mrg       r->_mp_size = sign_product >= 0 ? rsize : -rsize;
     83  1.1  mrg     }
     84  1.1  mrg   TMP_FREE;
     85  1.1  mrg }
     86