1 /* mpf_sqrt -- Compute the square root of a float.
3 Copyright (C) 1993, 1994, 1996 Free Software Foundation, Inc.
5 This file is part of the GNU MP Library.
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of the GNU Library General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or (at your
10 option) any later version.
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
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
15 License for more details.
17 You should have received a copy of the GNU Library General Public License
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. */
27 mpf_sqrt (mpf_ptr r, mpf_srcptr u)
43 usize = 1 - 1 / (usize == 0); /* Divide by zero for negative OP. */
44 r->_mp_size = usize; /* cheat flow by using usize here */
52 rexp = (u->_mp_exp + 1) >> 1; /* round towards -inf */
53 tsize = 2 * prec + (u->_mp_exp & 1);
56 tp = (mp_ptr) TMP_ALLOC (tsize * BYTES_PER_MP_LIMB);
62 MPN_COPY (tp, up, tsize);
66 MPN_ZERO (tp, tsize - usize);
67 MPN_COPY (tp + (tsize - usize), up, usize);
70 mpn_sqrtrem (r->_mp_d, NULL, tp, tsize);
72 r->_mp_size = (tsize + 1) / 2;